Published by Takahisa Nishikawa

Summary Analysis of weekly 500 hPa geopotential height forecasts suggests that the rainy season onset across much of Honshu may arrive slightly later than normal this year. By contrast, the end of the rainy season in southern Kyushu could come slightly earlier than normal. This stands in sharp contrast to last year’s exceptionally early rainy season, which concluded across most of the country — except Tohoku — by the end of June.

Background: Normal Timing and Last Year’s Contrast

The rainy season typically begins across most of Honshu between early and mid-June, with the end arriving between mid- and late July. Last year was a notable exception — the rainy season onset was exceptionally early across most regions (excluding Tohoku), and the end of the rainy season was similarly advanced, wrapping up by late June almost everywhere outside of Tohoku. This year’s pattern looks set to be quite different.

Methodology: Reading the Baiu Front and Pacific High From 500 hPa Heights

A well-established framework links the 500 hPa geopotential height field to the rainy season pattern: the Baiu front typically corresponds to the 5820 m contour, while the western Pacific subtropical high is associated with the 5880 m contour. The following analysis uses weekly 500 hPa GPH anomaly forecasts to assess the likely timing of rainy season onset and end by region.

Week 2 (June 8–15): Southern Kyushu May See Rainy Season Onset

The 5820 m contour is forecast to sit over southern Kyushu during this period, but does not extend to other regions. The 5880 m contour remains south of Okinawa. The rainy season onset looks possible for southern Kyushu during this window, but most of Honshu remains too early.

Week 3 (June 15–22): Rainy Season Onset Likely for Much of Honshu

The 5820 m contour advances northward to cover northern Kyushu, Shikoku, southern Kansai, Tokai, and Kanto. The 5880 m contour moves to near Okinawa. The rainy season onset is possible across northern Kyushu, Shikoku, Kansai, Tokai, and Kanto during this period. Okinawa may also see the end of its rainy season around this time.

Week 4 (June 22–29): Front Reaches Tohoku; Amami May See Rainy Season End

The 5820 m contour continues northward to southern Tohoku, while the 5880 m contour nudges slightly north of Okinawa. The rainy season onset is possible across the Chugoku region, Hokuriku, and Tohoku by the end of this period. The Amami Islands may also see the end of their rainy season around this time.

Week 5 (June 29 – July 5): Southern Kyushu May See Rainy Season End

The 5820 m contour advances to northern Tohoku, and the 5880 m contour moves northward to southern Kyushu. This suggests the end of the rainy season in southern Kyushu could arrive during this window. Note that Week 5 forecasts carry significant uncertainty and should be treated as indicative rather than definitive.

Bottom line: Taken together, the 500 hPa height analysis points to a rainy season onset that is slightly later than normal across much of Japan this year, while the end of the rainy season in southern Kyushu may arrive slightly earlier than normal. Week 5 uncertainty limits confidence at that range, but the overall picture contrasts clearly with last year’s exceptionally early rainy season. Further updates will be provided as the sub-seasonal forecast evolves.

Published by Takahisa Nishikawa

Summary The IMD’s May 15 press release placed the monsoon onset over Kerala at May 26 ± 4 days, but current conditions and the near-term forecast pattern suggest a slight delay is possible. The Northern Limit of Monsoon line has stalled near the Andaman & Nicobar Islands over the past few days, and the 850 hPa Zonal Wind Anomaly map indicates that sufficiently moist low-level westerlies are unlikely to reach the Kerala area through the end of May. From June onward, strengthening low-level westerlies should bring the onset back within the normal range. With El Niño expected to suppress convective activity and push total monsoon rainfall below normal this year, an early onset — or at least one that doesn’t slip too far — is particularly important for limiting the dry season risk.

Northern Limit of Monsoon: Progress Has Stalled

The latest monsoon onset map for India shows the Northern Limit of Monsoon (NLM) line covering the Andaman & Nicobar Islands, but forward progress has effectively stalled over the past few days.

The IMD’s May 15 press release forecast the monsoon onset over Kerala for May 26 ± 4 days. Based on current weather maps and near-term guidance, however, a slight delay beyond that window cannot be ruled out.

Why the Delay? Low-Level Westerlies Are Tracking Too Far South

Precipitation forecasts out to ten days show a drier-than-normal tendency over Kerala and southern India. One key factor is that the low-level zonal wind flow is meandering slightly southward over southern India, limiting the delivery of sufficient moisture to the Kerala region.

The 850 hPa Zonal Wind Anomaly map supports this assessment, indicating that the moist low-level westerlies needed for a monsoon onset are unlikely to reach the Kerala area in meaningful strength through the end of May.

From June: Westerlies Strengthen, Onset Expected Within Normal Range

From June onward, low-level westerlies are expected to strengthen, bringing the monsoon onset back within the climatologically normal range. The current delay appears likely to be temporary, but continued monitoring of model updates will be important as the situation evolves.

El Niño Influence: Below-Normal Rainfall Risk This Season

El Niño is expected to suppress convective activity across India this year, with total monsoon season rainfall forecast to run below normal. In this context, the timing of the onset matters more than usual — every day the monsoon arrives earlier helps reduce the cumulative rainfall deficit for the season. The onset date will be closely watched by agricultural, water resource, and energy sector stakeholders alike.

Published by Takahisa Nishikawa

Summary The next 15 days split into two distinct risk periods: multiple low-pressure systems through late May, followed by tropical storm risk from June 2 onward. Track and intensity uncertainty for the potential tropical system is extremely high, but some models suggest a possible approach toward the Kanto region in early June. On the sub-seasonal scale, a ridge-dominant pattern near Japan is expected from early June through early July, keeping temperatures near to slightly above normal. The rainy season onset looks on schedule or slightly early, with an earlier-than-normal end to the rainy season possible for eastern Japan.

First Half (Through May 29): Multiple Low-Pressure Systems

The low that brought cloudy and rainy conditions through today has moved off to the east. A new low developing over the waters south of Japan is expected to pass along the southern coast on May 23–24, raising the risk of below-forecast solar output on the Pacific side of eastern and western Japan.

May 25 brings a brief respite, with a mobile high bringing broadly clear skies across Japan.

From May 26, however, a new low approaching from the Chinese mainland will bring cloudy and rainy conditions to western Japan on May 27, spreading to eastern and northern Japan from May 28.

From May 29, a deepening low tracking east across the northern Sea of Japan will bring strong winds, particularly for eastern Japan, with widespread cloud and rain across northern Japan on the same day. May 30–31 and June 1 see high pressure return, with broadly clear and settled conditions expected across Japan.

Second Half (From June 2): Tropical Storm Risk Emerges

No tropical storms are currently being monitored by the JTWC. However, from late May, several global models are suggesting the possibility of tropical cyclone development east of the Philippines. Track and intensity uncertainty is extremely high, but some models point to a possible approach toward the Kanto region in early June. Updates will be provided frequently as the situation develops.

Temperature

Temperatures in eastern Japan will run slightly below normal through May 24, before recovering to near- or slightly above-normal from May 25 onward. May 25 stands out as a potential midsummer-like day, with parts of the Kansai region possibly reaching 30°C under the influence of the high. The above-normal temperature tendency is expected to continue thereafter, though tropical storm uncertainty introduces meaningful variability risk to the temperature outlook from June onward.

Precipitation

Above-normal precipitation is expected across northern and eastern Japan through the period, with slightly above-normal totals also possible along the coast of western Japan. While no extreme dry risk is apparent, a low-pressure system around May 27 carries the risk of heavy rainfall in Kyushu. Precipitation forecasts for the latter half of the period are highly sensitive to the tropical storm track.

Solar

Solar output will be disrupted at times during the first half of the period due to frequent low-pressure passages, but May 25, 30, and 31 stand out as favorable days under high-pressure influence. Output looks modestly above normal from June 1, but remains highly sensitive to the tropical storm track.

Sub-Seasonal Outlook (Early June Through Early July)

A ridge-dominant pattern is expected near Japan from early June through early July, with positive height anomalies centered on eastern and northern Japan. A trough is consistently forecast near northern China and the Korean Peninsula through this period. Temperatures are expected to run near to slightly above normal, with medium confidence in this outlook.

A low-pressure anomaly is expected through mid-June, bringing slightly above-normal precipitation in the first half of June. From Week 4 onward, a high-pressure anomaly begins to emerge over eastern Japan, shifting eastern Japan toward near- to slightly below-normal precipitation, while western Japan remains prone to above-normal rainfall from moist southerly flow around the ridge.

Solar output will be slightly below normal for eastern Japan in the first half of the sub-seasonal period, shifting to below normal for western Japan around Week 5 (late June). In Week 6 (late June through early July), a scenario where high pressure covers all of Japan emerges, which could bring a favorable period for solar power generation.

The rainy season onset is expected near normal or slightly early. The end of the rainy season in eastern Japan may also arrive slightly ahead of schedule.

Tropical Storm Strike Risk

ECMWF Tropical Storm Strike Probability guidance shows elevated approach risk for eastern and western Japan through June. While tropical cyclone formation probability in the Philippine Sea and northwest Pacific from mid-June onward is not particularly high, there is also the possibility of extratropical low-pressure development near Japan. Either way, the guidance points to elevated heavy rainfall risk, and the track of any tropical or low-pressure disturbance warrants close monitoring.

Published by Ed Vallee

The 14 day national demand change since yesterday is +1.2 CDDs…

Modeled temperatures next 15 days:

Our forecast in terms CDDs with changes since yesterday:

Degree day info, noting we continue to be on the warmer side of guidance throughout the period.

Looking at day 15, June 2nd, ridging remains focused across the northern tier, but extreme heat is hard to come by: lots of 80s across MISO and PJM.

The 15 day precipitation forecast is starting to resemble El Nino, with precipitation focused across the southern tier, including Texas:

Published by Takahisa Nishikawa

This article summarizes the factors behind the cool conditions in late May last year, the warming trend from mid-June onward, and the outlook through the end of June this year.

In summary, we currently assess the risk of a significant cool spell in late May this year, similar to last year, as relatively low. On the other hand, for the latter half of June, while a prolonged period of strong heat like last year is not the base-case scenario at this stage, short-lived heat events may still require attention depending on the timing of any break in the rainy season.

Late May to Early June

Last year: Cool conditions in late May due to the influence of a trough and frequent rainfall

The main reason for the cool conditions in late May last year was that an upper-level trough, or a low-pressure trough, tended to remain near Japan, allowing cold air to flow into the region.

In particular, the 500 hPa height field showed that western Japan was prone to the influence of the trough. In the lower levels, moist air also flowed in easily, and the rainy season began early, leading to above-normal precipitation in late May.

As a result, the combined effects of cold air, frequent rainfall, and reduced sunshine made it difficult for temperatures to rise, leading to below-normal temperatures.

This year: A dominant ridge pattern makes a sustained cool spell like last year unlikely

By contrast, for late May to early June this year, the current forecasts have been relatively consistent in indicating a dominant ridge pattern, suggesting a tendency for temperatures to be above normal.

The ECMWF ensemble forecasts do not currently show a clear signal of a long-lasting trough near Japan, as was observed last year.

Therefore, at this stage, we consider the likelihood of a sustained period of significantly below-normal temperatures, similar to last year, to be low. That said, there may still be short periods when temperatures are near normal or slightly below normal.

Late June

Last year: Heat in late June driven by a ridge pattern and surface high pressure

From mid- to late June last year, a ridge pattern, or anticyclonic pattern, persisted in the upper levels near Japan.

In addition, surface high pressure frequently covered the region, creating conditions that were unusually favorable for temperatures to rise during the rainy season. As a result, Japan was covered by very warm air, leading to intense heat from mid- to late June.

This heat event was one of the key characteristics of last June.

This year: A ridge as strong as last year is unlikely at this stage, but short-lived heat events remain possible

For the latter half of June this year, current forecasts do not indicate a ridge pattern as strong as the one observed last year.

Therefore, a prolonged period of extreme heat similar to last June is not considered highly likely as the base-case scenario at this point.

However, if a break in the rainy season allows high pressure to cover Japan while the upper-level ridge strengthens at the same time, there is still a meaningful possibility that heat comparable to last year could persist for around two to three days.

Summary

Taking these points together, we currently assess that a sustained cool period similar to last year is unlikely from late May to early June this year. For the latter half of June, however, the main risk to monitor is not necessarily a prolonged extreme heat event, but rather short-lived periods of intense heat.

As the forecast may change with future updates, it will be important to continue monitoring the latest ensemble forecasts and cluster analysis and update the outlook accordingly.

Published by  Amy Hodgson

The Panama Canal is a major global shipping route, shortening transit times between the east and west coasts of the Americas. Severe drought in 2023 and into 2024 reduced Panama Canal transits by around 30% as low water levels limited canal operations. The main reservoir feeding the canal is Gatun Lake which has strong seasonal variability. The plot below shows the monthly average water levels over the past five years:

Taking a closer look at the yearly levels for May and August below, clearly shows the extremely low levels during the El Nino of 2023 and to begin 2024.

The strong El Nino through 2023-2024 is considered to have played a significant role in these drought conditions leading to the canal operating well below capacity. Daily transits dropped to as low as 24 vessels and maximum drafts fell below 44 feet. By later 2024 and through 2025, a change to La Nina conditions led to an increase in rains across the region and hence the canal returned to normal operations.

So, what is the current situation and the outlook through 2026?

Local observations show water levels in Gatun Lake ranging between 85.7ft to 86.2ft over the past week.

The water level projection plot below does forecast an increase in levels over the next month as expected due to strong precipitation seasonally  across the region.

The latest ENSO guidance from the ECMWF below forecasts a strong El Nino developing as we move through the summer and into autumn. A reminder that the 2023-2024 drought occurred during El Nino conditions.

El Nino generally brings drier conditions across the Caribbean, including the Panama Canal region through summer, therefore a close eye needs to be kept on the forecast heading through the year.

The C3S seasonal guidance shows generally shows near normal precipitation amounts in June, before then drier than normal conditions through the rest of summer and into autumn. This would therefore limit precipitation input into Lake Gatun and have implications on water levels in the Panama Canal through the summer and into autumn. There is the increasing risk that this summer could have vessel restrictions if the expected drought conditions come to fruition.

Bottom line: There is the increasing risk of drier than normal conditions returning across the Panama Canal region moving through 2026 as we transition to a possible strong El Nino state. Drier than normal conditions would limit precipitation input into Lake Gatun which is the main reservoir feeding into the canal. This would therefore have a knock on effect on canal levels which if water levels drop low enough, could potentially lead to vessel restrictions moving through the year.

Published by  Amy Hodgson

Here we take a look at the latest hydro situation across Brazil, and the precipitation outlook as we move through Spring and into Summer. The previous Brazil hydro blog issued late March can be found here https://www.ag2trader.com/1-15days/?blogPostID=190361

Brazil is one of the largest producers of hydroelectric power in the world, with the largest hydroelectric dam here being the Itaipu Dam. The primary reason for importing LNG into Brazil is to make up for the lack of electricity produced by the Itaipu Dam and other dams across Brazil, especially during times of drought. During times of drought, Brazil relies upon import LNG to meet its power needs. Therefore it’s crucial to monitor Brazilian precipitation.

Over the past 90 days, conditions have been slightly drier than normal across much of Brazil, except nearer normal across the far east. While over the past 30 days, it’s been particularly dry across south-eastern Brazil.

The latest soil moisture data from NASA shows largely dry soils, particularly across the interior regions of Brazil, although there are some localised wetter soils across the north-east:

Now looking at the latest hydropower reservoir levels (https://www.ons.org.br/paginas/energia-agora/reservatorios). Compared to our last update https://www.ag2trader.com/1-15days/?blogPostID=190361, levels have increased across all regions. However, southern regions still remain low.

Now looking ahead to the forecast, the precipitation anomalies from the ECMWF and the GFS over the next 15 days are shown below. Generally a dry outlook continuing across much of Brazil, the exception being wetter across the far south, and across the far north.

The latest ECMWF weekly below shows wetter conditions across the far north of Brazil weeks 21 and 22, with near normal to drier than normal across much of Brazil. Weeks 23 and 24, generally near normal precipitation across much of Brazil.

The C3S seasonal guidance below shows near normal precipitation forecast through the summer across central Brazil, with a generally drier far north and wetter south pattern.

El Nino conditions are forecast as we move through summer, possibly reaching strong levels. El Nino conditions through summer, generally favor a drier Caribbean and into northern Brazil as shown in the graphic below, which is in agreement with the C3S forecast for summer.

Bottom line: Over the past month reservoir levels across Brazil have increased slightly, however levels across the south remain low. The forecast over the 2 weeks is for generally a dry outlook continuing across much of Brazil, the exception being wetter across the far south, and across the far north. Then through the summer, the C3S seasonal guidance shows near normal precipitation forecast across central Brazil, with a generally drier far north and wetter south pattern. This drier north pattern is typical of an El Nino pattern which is forecast as we move through 2026.

Published by Ed Vallee

Changes:

Week 1-3: Cooler West, Warmer Central

Week 4: Cooler Northeast, Warmer Rockies

Week 5: Cooler PNW

CDD Info noting 10 CDDs gained versus yesterday’s forecast.

Published by Ed Vallee

Today’s 12z overview for the next 15 days is shown below.

Degree Day Info:

Published by  Takahisa Nishikawa

May 1: Cold Air Advection Drives Sharp Temperature Drop

Today’s AG2 forecast brings a meaningful downward revision to temperatures across Japan from April 29 through May 7. The most striking change is in Tokyo, where the daytime high on April 30 has been revised down by 4°C from yesterday’s forecast.

The main driver is cold air advection following a low-pressure system passage. Models are broadly aligned on the depth and position of the associated trough, lending relatively high confidence to this near-term forecast.

From April 29 to May 1, minimum temperatures are expected to fall to single digits across a wide area of northern and eastern Japan. This raises the prospect of an uptick in morning and evening heating demand that warrants attention from power and gas market participants.

From May 2: Ridge Returns, Temperatures Recover

Will this cold spell last? The answer is no.

From May 2, a ridge pattern is expected to establish itself over Japan, bringing a return to near- to slightly above-normal temperatures.

This cold episode should be seen as a short-term fluctuation rather than a signal of any sustained seasonal shift.

Published by Amy Hodgson

Here we take a look at the large scale atmospheric pattern through days 6-10 and 11-15.

The graphics below show the latest ensembles for mid week 16, Wednesday 15th April. The models are in close agreement of a Nordic high, with higher pressure extending across much of Europe.

Then by late week 17, the ensembles below show the high retrogressing to Greenland, with the NAO dropping to negative territory. There’s overall good model agreement in the broad pattern trend to a reduction in the NAO index.

This NAO drop late April has been highlighted for a while now, as the MJO moves across the western Hemisphere:

A quick look at the FRisk graphics below actually shows plenty of green across Europe from day 7 onwards indicating lower than normal forecast risk, or that there is higher than normal forecast confidence.

Expectations as the NAO drops to negative week 17?

The latest AG2 temperature forecast for the 11-15 day timeframe is shown below with northern-central to north-eastern Europe highlighted as the area where there is greatest cooler risk to the forecast. Conditions are also forecast to be drier than normal across northern and central Europe, with low winds and high solar here. While to the far south of Europe, slightly below normal to near normal precipitation, mostly low winds and below normal solar potential.

Published by Amy Hodgson

Here, we present the latest Saharan dust outlook across Europe through the rest of this week.

With lower pressure in the vicinity of Iberia, this is resulting in a southerly airflow around it’s western flank, transporting Saharan dust northwards across Iberia:

The latest dust load forecast from the University of Athens below shows the highest dust load currently across Iberia to western France. Then by Saturday, elevated levels are forecast across much of western Europe edging into central Europe and across Germany on Sunday which gives the downside risk to solar generation.

The Barcelona Dust Regional Centre dust load forecast below shows a similar pattern of higher levels across Iberia, with lower levels spreading to north-western and central Europe over the next few days.

So why Saharan dust important?

Saharan dust can have an impact on solar power generation both directly and indirectly. Directly, dust in the atmosphere blocks and scatters solar radiation from the sun, hence less incoming radiation hitting solar panels, thereby reducing generation. Dry deposition of the dust directly settling and building up on the panels will also reduce the power generation. Wet deposition, the process of removal of dust from the atmosphere by precipitation can also lead to dust build up on panels and reduced generation. Finally indirectly, Saharan dust in the atmosphere can act as cloud condensation nuclei (CCN), which is needed for clouds to form. Therefore dust in the atmosphere acting as CCN can lead to an increase in cloudiness, thereby reducing incoming solar radiation leading to a reduction in solar generation.

Risks are therefore to the downside for solar across Iberia through the rest of this week, with lower dust levels also reaching across France and then Germany by front weekend.

Published by Takahisa Nishikawa

Summary: NOAA puts the probability of El Niño this summer above 60%. However, spring forecasts are inherently uncertain. Past cases show that early signals often fail to materialize. Markets may price in El Niño risk, but overconfidence is risky. Treat forecasts as probabilities, not certainties.

Figure 1: ENSO Probabilities by NOAA as of March, 2026

Risks in Spring El Niño Forecasts

NOAA’s latest outlook may have led traders to price in El Niño trend. But building positions based on spring forecasts alone can be risky.

This is due to the “spring predictability barrier,” when forecast skill is structurally lower.

What History Tells Us

2014: Strong signal that failed

• Forecast pointed to a very strong El Niño
• Actual warming was limited
• Strong signals can lead to market overreaction

Figure 2: July SST analysis values ​​(left), forecast (center), and error (right) by JMA with initial values ​​in April 2014

2012: Event declaration reversed

• JMA initially declared an event
• Later revised to no event
• Even “declared” events may not hold

Figure 3: July SST analysis values ​​(left), forecast (center), and error (right) by JMA with initial values ​​in April 2012

Why Spring Forecasts Struggle

From March to May, trade winds and ocean temperatures fluctuate more. This makes initial conditions unstable in models. Forecast skill improves after June as ocean-atmosphere feedback stabilizes.

Trading Implications

1. Keep alternative scenarios

Even if an El Niño is forecast, the underlying warming trend means localized extreme heat cannot be ruled out.

Traders should therefore keep hedges for a “La Niña-like” hot scenario if the forecast fails.

In Japan, this risk is especially important. Under La Niña or neutral conditions, sea surface temperatures east of the Philippines tend to rise. This enhances convection, which strengthens the Pacific High (PJ pattern). As a result, the risk of extreme heat in Japan increases.

In short, even without El Niño, the risk of a hot summer remains significant.

2. Avoid full commitment until forecast convergence in June

Forecast skill tends to improve after June, once the spring predictability barrier passes.

JMA data shows that forecasts issued in April lose accuracy beyond a three-month horizon, while forecasts from June maintain relatively better skill up to six months ahead.

Figure 4: SST accuracy evaluation of the Niño 3.4 area with initial values ​​in April

Figure 5: SST accuracy evaluation of the Niño 3.4 area with initial values ​​in June

This highlights the high uncertainty in spring forecasts.

Until then, it is prudent to keep positions smaller and manage volatility using options or similar tools.

3. Watch the Pacific High directly

Japanese demand depends more on the Pacific High than ENSO itself. Monitoring its strength can help detect forecast errors early.

Bottom line: El Niño forecasts are probabilistic, not certain. History shows that forecasts can fail. Flexible scenario planning remains essential for energy markets.

Published by Ed Vallee

This blog takes a look at the latest drought monitor, which was issued on April 2nd.

The latest drought monitor is below, noting drought coverage is up to 80.01 % (up from 77.14% last week).

Month over month change maps are below. The most notable trends in the last month are wetter in parts of the Ohio River Valley and Northeast, but drier in parts of the Rockies, Plains, South, and West.

The forecast over the next 15 days is fairly dry across the West and Southeast, but the Central U.S. looks active!

Published by Amy Hodgson

This blog gives an overview of the latest German wind outlook through the end of March and into April.

Through mid this week, a cold plunge will move into northern-central Europe as a result of higher pressure to the west, with lower pressure to the north-east. Alongside the drop in temperatures, a tight pressure gradient across northern mainland Europe will lead to a peak in German winds to high levels on Wed 25th March, reaching mid 40GW levels.

Then through the end of the working week, a gradual decline in German winds is forecast as a ridge of higher pressure builds in by Fri 27th March with winds dropping to lower levels:

For week 14 (w/c 30th March), mostly moderate wind power potential is forecast for Germany due to the pressure gradient between higher heights to the west and lower heights to the north-east:

However through the end of week 14, higher pressure starts to try to extend north-eastwards. Therefore there is a downside risk to German wind power potential late week 14.

The latest EC46 then forecasts lower than normal wind power potential for Germany through weeks 15 and 16 under higher pressure.

Bottom line: A peak to high wind power potential for Germany this Wed 25th March in a strong northerly airflow off the North Sea, with peak levels forecast to reach mid 40GWs. Then through the end of this week, wind will drop back to lower levels as a brief ridge of high pressure moves in. For week 14, generally a moderate wind week is forecast to Germany in a decent pressure gradient between higher pressure to the west, lower pressure to the north-east. Risks appear more to the downside late week 14 as higher heights extend towards the north-east. Finally into weeks 15 and 16, the latest EC46 is forecasting low winds under higher pressure.

Published by: Amy Hodgson

The temperature forecast changes vs the previous forecast are shown below. Slightly milder across eastern Europe weeks 13 and 14. Otherwise, no significant changes.

Week 13

Pattern: +NAO. Higher heights across north-eastern Europe with weak troughing across the south.

Temperatures: Widely above normal, highest anomalies to the north-east. Nearer normal temperatures across Iberia.

Hydro: Mostly near normal. Wetter to the far south-east.

Wind: Above normal northern Europe. Below normal southern Europe.

Solar: Mostly slightly above normal except below across the south-east.

Risk/confidence: Majority of EC46 clusters continue to support a mild week, although with differences in exact pressure pattern. Continued risk that potential MJO movement towards the western hemisphere and potential stratospheric impacts could come into play late March/early April giving colder risks to the forecast, but uncertainty lies in the strength of this large scale forcing.

Week 14 

Pattern: -NAO. Higher heights across northern Europe, with weak troughing across southern Europe.

Temperatures: Above normal, highest to the east. With nearer normal temperatures to the south-west.

Hydro: Near normal to slightly drier than normal across northern Europe, wetter across the south.

Wind: Mostly near normal to slightly below normal.

Solar: Above normal across the northern half of Europe, below across the south.

Risk/confidence: Majority of EC46 clusters continue to favour a mild outlook but again differ in the exact details of the pattern. Trend towards a more blocked pattern/-NAO look seem reasonable with potential MJO and stratospheric impacts which could come into play late early April giving less mild/colder risks to the forecast.

Week 15

Pattern: -NAO. Weak troughing across north-eastern Europe.

Temperatures: Mostly near normal to slightly above normal.

Hydro: Mostly near normal, slightly above across the north-east.

Wind: Mostly near normal. Slightly below to the south-west.

Solar: Mostly near normal to slightly above.

Risk/confidence: Confidence dropping with more variable clusters – top two present colder risks across northern Europe. Clusters do support a continuation of some sort of high latitude ridging but differ in the details.

Week 16

Pattern: Weak -NAO with weak troughing across northern Europe, weak ridging across the south.

Temperatures: Slightly above across western and central Europe, nearer normal across the east.

Hydro: Mostly near normal. Slightly below eastern Iberia.

Wind: Mostly near normal. Slightly below Iberia.

Solar: Slightly above across western Europe and the Mediterranean. Below across eastern Europe.

Risk/confidence: Lower confidence with poor cluster agreement. Top two clusters (22% and 21%) bring back lower pressure to northern and western Europe. While third cluster (16%) persists with high latitude ridging.

GFS Weekly:

The latest GFS weekly below is forecasting a -NAO pattern weeks 13 to 15 bringing higher pressure to northern Europe, and lower heights to southern Europe. Generally in broad agreement with the EC46 large scale pattern, although detail differences in the exact placement of higher heights to the north and lower heights to the south.

Bottom line: The latest EC46 and GFS weekly are in broad agreement in a more -NAO/high latitude ridging pattern developing through late March and into April. Temperatures are overall forecast to trend less mild, albeit remaining slightly above the seasonal normal in the latest EC46 guidance which would generally bring a more settled northern Europe and more unsettled southern Europe pattern. There continues to be some colder risks from clusters, alongside MJO forcing and potential stratospheric implications although confidence in the detail is low.

The satellite image from yesterday below, clearly shows the hazier skies across Iberia, the Mediterranean to Italy associated with the current Saharan dust outbreak:

While the images below show the dustier skies now spreading across France towards the British Isles. Dust in the bottom image is shown by the pink shading.

The latest dust load forecast from the University of Athens below shows the highest dust load currently across parts of Iberia, France to southern areas of the British Isles today, before then spreading to Benelux and Germany tomorrow. Through front weekend, dust levels are forecast to remain elevated across northern Europe.

The Barcelona Dust Regional Centre forecast to aerosol optical depth (AOD) below shows a similar pattern of higher levels spreading across northern Europe over the next few days.

So why Saharan dust important?

Saharan dust can have an impact on solar power generation both directly and indirectly. Directly, dust in the atmosphere blocks and scatters solar radiation from the sun, hence less incoming radiation hitting solar panels, thereby reducing generation. Dry deposition of the dust directly settling and building up on the panels will also reduce the power generation. Wet deposition, the process of removal of dust from the atmosphere by precipitation can also lead to dust build up on panels and reduced generation. Finally indirectly, Saharan dust in the atmosphere can act as cloud condensation nuclei (CCN), which is needed for clouds to form. Therefore dust in the atmosphere acting as CCN can lead to an increase in cloudiness, thereby reducing incoming solar radiation leading to a reduction in solar generation.

Risks are therefore to the downside for solar across Iberia, France and the British Isles today, with the main downside risks on Friday being across the British Isles to Benelux and Germany. Then through front weekend, slight downside risks across northern Europe.

This is a follow-up blog to an earlier article available at https://www.ag2trader.com/1-15days/?blogPostID=190084, taking it to the main large-scale driver for Europe in the sub-seasonal space this time of the year (MJO and Stratosphere). The MJO could be speeding up and, reinforced by a Kelvin Wave, could start stimulating a pattern transition into the back half of March towards lower NAO values, while the unfolding SSW in the background struggles to show clear footprints.

Tropical convection is forecast to emerge in the Atlantic basin into mid-March, and it has been monitored for a while for its potential to be a cold trigger for Europe. The latest projections suggest that such convections could be supported by active phases of both the MJO and a Kelvin Wave. If those two oscillation synchronize could provide a larger magnitude forcing as a consequence on to the NAO index.

At the minute, as discussed in our previous blog, less +ve NAO conditions are forecast into W12. Based on the plots below, the risks is to see an increased downward forcing on that index W12+.

Compared to a couple of days back, the latest filtered velocity potential forecasts from ECMWF, show a quicker E’ward progression of tropical convection (some combination of MJO and Kelvin Wave) towards the Americas and the Atlantic. Quicker arrival of more organized convection into the Atlantic equals earlier and perhaps higher risks of seeing a colder or at least less mild shift in Europe.

The wheeler diagrams presented below shows that while EC now brings the MJO into phase 8 (increased colder risks for Europe) later in March, GFS lingers behind over the Pacific. Quite some spread there…

And obviously his highness, the Polar Vortex. A split-vortex type major SSW is unfolding.

Anomalous warmth is forecast to rapidly propagate downward through the stratosphere, but coupling with the troposphere doesn’t look too impressive at the minute. We should not ignore longer wave downwelling either, which could extend the risks of seeing stratospheric forcing later in the month if not even further.

The AO forecast is the main detractor of a stronger stratosphere-troposphere coupling event. Tighter coupling would in fact skew the AO towards negative values, while the latest projections resolve an overall +AO through the next couple of weeks, limiting the Arctic’s propensity to open its cold-air taps for now.

Bottom Line: The latest EC projections show a quicker E’ward propagation of the MJO towards the Atlantic by mid-month. If this is confirmed and aligns with a Kelvin Wave also reaching the Atlantic in a similar timeframe, we could see colder/less mild risks increase for Europe W12+, along with a descent of the NAO index. Meanwhile, an unfolding split-vortex type major SSW in the background also suggests colder risks through March if not beyond, while an AO seemingly locked in a +ve phase would limit the supply of colder air. We should however closely monitor any further MJO evolution now and as well as any potentially tighter coupling between stratosphere and troposphere for clearer signals towards stronger forcing to a pattern shift in Europe later in March.

Latest observations show that snowpack is below normal across most of Japan. Areas with above-normal snow are limited to parts of Hokkaido and northern Tohoku.

Reservoir storage is also low, with many dams sitting below 50% capacity, reflecting the dry winter conditions.

Precipitation over the next two weeks is very likely to remain below normal, and there is no strong signal for above-normal rainfall even out to around five weeks.

At the same time, the 3-month temperature outlook is near to above normal, suggesting earlier-than-usual snowmelt in mountain areas.

This creates a mixed hydro picture: earlier snowmelt could temporarily support hydro generation in March–April, but if rainfall remains limited into May and beyond, inflows may weaken and hydro availability could decline later in spring.

Summary

East Asia saw a broadly warm month, driven by a relatively mild upper-level pattern despite occasional cold intrusions. Over Japan, low- and high-pressure systems moved through in a fast cycle, and winter monsoon conditions did not persist for long. Early in the month, a brief but strong winter pattern pushed cold air south, producing heavy snowfall across the Sea of Japan side and, locally, the Pacific side. Mid-to-late month was generally dry as storm tracks were limited, before more organized rain arrived later, especially across northern/eastern Pacific-side Japan and western Japan. Temperatures were notably above normal across northern/eastern Japan and eastern/southern China. Solar conditions were generally favorable outside northern China.

Synoptic pattern

Low- and high-pressure systems moved through from China toward Japan in a recurring cycle. In Japan, winter-monsoon (“winter-type”) patterns did not persist for long, and there were periods dominated by mobile high pressure. Early in the month, a brief but strong winter pattern pushed cold air south, bringing heavy snow mainly to the Sea of Japan side of eastern and western Japan, with localized heavy snow also on the Pacific side.

Through the first part of the late month, storm and frontal impacts were limited and precipitation stayed generally low. From mid-to-late month, lows and fronts became more active again, bringing more organized rainfall, especially across northern/eastern Pacific-side Japan and western Japan.

Upper-level pattern (500mb GPH) and temperature anomalies

The polar-front jet occasionally dipped south near northern Japan, allowing some cold intrusions. However, 500mb height anomalies were often positive near Japan, limiting sustained upper-level cold influence. At the surface, both the Aleutian Low and the Siberian High were relatively weak.

Temperature

Temperatures were above normal across much of East Asia, with the strongest warm anomalies over northern/eastern Japan and eastern to southern China.

Precipitation

Precipitation was above normal in northern Japan, western Japan, Northeast China, and parts of eastern China, while eastern Japan, South Korea, and southern China were drier than normal.

Wind

Winds were stronger than normal in China, South Korea, and parts of northern Japan, while the Pacific side of Japan and the Okinawa region were relatively lighter.

Solar radiation / cloud cover

Solar conditions were favorable across Japan, South Korea, and eastern/southern China, while northern China saw slightly weaker solar due to cloudier conditions.

Archives

• January, 2026: https://www.ag2trader.com/1-15days/?blogPostID=189802
• December, 2025: https://www.ag2trader.com/1-15days/?blogPostID=189480

Temperature

This winter was warmer than normal across much of East Asia, except parts of northern China.

Comparing AG2’s late-November outlook for Dec 2025–Feb 2026 with NOAA reanalysis, results were generally strong for Japan and South Korea. In northern China, the forecast was warmer than observed, while in southern China it was cooler than observed.

Precipitation

Precipitation was below normal across eastern/western Japan, South Korea, and southern China, while northern Japan and northern China were slightly wetter than normal.

Against our late-November forecast, agreement was particularly good for Japan, South Korea, and southern China, suggesting the broad precipitation signal was captured well.

Sea-level pressure (SLP)

SLP was lower than normal across much of East Asia, while higher-than-normal pressure was present near the Aleutians. This setup made persistent “classic winter monsoon” patterns less likely. Cold-air outbreaks occurred mainly in January and early February, but they were generally short-lived.

500 hPa height anomalies (Z500)

Ridging near the Aleutians extended toward East Asia, and the jet stream tended to shift northward and meander more than usual.

However, a notable cold push reached northern China and Japan in late January to early February.

This has been linked to a negative Arctic Oscillation (AO) and enhanced convection east of the Philippines, which may have helped amplify a wave pattern and support blocking near Alaska (see JMA reference, Japanese only).

Tropical Cyclone Horacio is currently churning across the southwest Indian Ocean, east of Madagascar and near Mauritius and Réunion, displaying a well-defined spiral structure with a dense, powerful core. Satellite imagery shows tightly wound rainbands wrapping around a bright central mass of thunderstorms, a sign of an organized and strengthening system. Forecast data indicates Horacio has reached cyclone intensity, with winds around 110 mph and pressure near 963 mb at peak strength, and it is expected to gradually curve southward over open waters in the coming days. While the storm’s projected path keeps the most destructive winds offshore, outer rainbands could still bring rough seas, gusty winds, and heavy rainfall to nearby islands.

I’ve recently heard some chatter in the market and received several questions about whether warmer or cooler water temperatures around Baja California could meaningfully impact ERCOT’s summer outlook. While it’s a fair question — especially given how sensitive Texas power markets are to summer heat — the reality is that Baja sea surface temperature anomalies are rarely a primary driver on their own. There are bigger and more influential climate forces at play heading into summer 2026.

Water temperature anomalies around Baja California are often not studied in isolation, but instead as part of much larger Pacific Ocean patterns that influence weather across North America. In climate research, SST anomalies along the Baja and southern California coast are frequently embedded within broader ocean–atmosphere modes such as the Pacific Meridional Mode and the Pacific Decadal Oscillation. These patterns can extend from the northeast Pacific toward the tropics and are important because they help shape or even initiate larger climate events like El Niño and La Niña. Because Texas weather is strongly affected by these large-scale Pacific influences, Baja-region SST anomalies can sometimes serve as an indicator of broader Pacific conditions that may later impact temperature patterns farther inland — but they are typically a secondary signal rather than a standalone driver.

The dominant factor right now is ENSO. The current Niño 3.4 plume guidance shows a rapid transition toward a strong El Niño by late spring and summer 2026. When ENSO strengthens at that magnitude, it becomes the primary architect of hemispheric-scale circulation patterns. Strong El Niño events reshape jet stream positioning and subtropical ridging, altering storm tracks and heat distribution across North America. That larger Pacific base state will matter far more for ERCOT summer risk than marginal SST anomalies near Baja.

A useful analog is summer 2023. The composite reanalysis for June–August 2023 shows a distinctly hotter-than-normal signal across Texas, especially central and eastern portions of the ERCOT footprint. Precipitation anomalies during that summer were also below normal across much of Texas and the southern Plains. That combination — suppressed rainfall and persistent heat — drove elevated cooling demand and prolonged stress on the grid. The current setup shares some structural similarities, particularly in how Pacific forcing can favor ridging over the southern U.S.

JUNE-AUGUST 2023 PRECIPITATION ANOMALY

However, there is an important difference: drought conditions today are more widespread and more entrenched across parts of Texas and the southern Plains than they were in February 2023. Comparing the February 2023 drought monitor to the current map shows broader coverage of moderate to extreme drought categories. That matters because dry soils amplify heat. When the land surface lacks moisture, less energy goes into evaporation and more goes directly into warming the air. This land–atmosphere feedback can intensify heat waves and reduce afternoon cloud development, reinforcing a hotter and drier regime.

Current ocean data and seasonal forecast guidance point toward the development of a strong El Niño during summer 2026, and that shifts the discussion for Japan compared to the past two years. Japan’s summer weather plays a critical role in the global LNG market because the country is one of the world’s largest importers of liquefied natural gas. Hotter-than-normal summers drive strong electricity demand for air conditioning, which in turn increases gas-fired power generation and LNG imports. When Japan’s cooling demand surges, it can tighten spot LNG supply across Asia, influence benchmark prices such as JKM, and ripple into European gas markets as cargoes are redirected. As a result, even subtle shifts in Japan’s summer temperature outlook can have outsized effects on global LNG pricing and trade flows.

Looking back, the most recent strong El Niño peaked in late 2023 into early 2024, with Niño 3.4 sea surface temperature anomalies well above +2°C. By summer 2024, that event was already weakening toward neutral, and by late 2024 into 2025 the signal shifted slightly negative, reflecting weak La Niña conditions. As a result, summers 2024 and 2025 were not dominated by strong ENSO forcing; both occurred under weak La Niña or near-neutral backgrounds, meaning the tropical Pacific did not provide a pronounced large-scale driver.

The current C3S multi-system plume issued in February 2026, however, shows a clear upward trajectory in Niño 3.4 anomalies through boreal spring into summer, with many ensemble members reaching or exceeding +1.5°C and some approaching or surpassing +2°C by early to mid-summer. That places 2026 on track for a potentially strong El Niño.

Importantly, verification of the February 2023 C3S forecast for the 2023–24 event shows that the multi-model ensemble underforecast the eventual peak strength of El Niño. The observed anomalies ultimately rose higher than many of the ensemble members had projected at comparable lead times. This underforecast bias is worth keeping in mind for 2026: if models are again slightly conservative, the eventual strength of this summer’s El Niño could exceed the current ensemble mean.

Summary: During the month, East Asia experienced a highly variable winter pattern driven by a negative Arctic Oscillation and intermittent blocking over eastern Siberia. Winter-type pressure patterns dominated early and late in the month, bringing heavy snowfall to the Sea of Japan side of Japan. Mid-month, frequent low-pressure systems tracked across northern Japan, while eastern and western Japan remained under high pressure and relatively dry. Temperatures were near normal in Japan, below normal in Korea and northern China, and above normal across much of China. Precipitation was concentrated in northern regions, while solar radiation remained strong across much of Japan, Korea, and southern China, supporting generally favorable solar generation conditions.

Synoptic pattern

Source: JMA

During the early and late parts of the month, winter-type pressure patterns frequently developed. When these patterns strengthened, heavy snowfall occurred across the Sea of Japan side of northern, eastern, and western Japan.

In the middle of the month, low-pressure systems often moved from the Sea of Japan into northern Japan, while high pressure dominated eastern and western Japan.

Throughout the month, the Pacific side of eastern and western Japan was less affected by passing lows, and northern Japan’s Pacific side was also relatively sheltered during the early and late periods.

Upper-level pattern (500 hPa GPH) and temperature anomalies

Source: JMA

At 500 hPa, a negative Arctic Oscillation prevailed. As part of this pattern, a blocking high formed over eastern Siberia, allowing part of the polar vortex to extend southward toward Sakhalin.

The polar front jet stream meandered south near Japan, periodically allowing upper-level cold air to affect the region, especially northern Japan.

At the surface, negative pressure anomalies dominated from the Sea of Japan to the Okhotsk Sea. This led to alternating periods of strong winter monsoon flow with cold air outbreaks, and periods when warm air flowed toward lows tracking over the Sea of Japan.

At times, the Siberian High extended toward western Japan and even Okinawa, reducing the influence of low-pressure systems across much of Pacific-side Japan.

Temperature

Temperatures were generally near normal in Japan, below normal in Korea and northern China, and above normal across most other parts of China.

Precipitation

Precipitation was above normal along the Sea of Japan side of Japan, northeastern China, and parts of eastern China. Elsewhere, conditions were drier than normal, with particularly dry conditions on the Pacific side of Japan.

Wind

Winds were stronger than average across much of East Asia, while the Okinawa region experienced relatively lighter winds.

Solar radiation / cloud cover

Solar radiation was stronger than normal across eastern and western Japan, Korea, and eastern and southern China, but weaker than normal in northern China.

Archives

December, 2025: https://www.ag2trader.com/1-15days/?blogPostID=189480

The temperature forecast across PJM shows a clear progression from colder-than-normal conditions early in the period toward a gradual moderation later on. The initial stretch of below-normal temperatures will drive higher heating demand and elevated electricity load across the region, particularly during morning and evening peak hours. As the forecast trends closer to seasonal norms and eventually warmer-than-normal conditions, heating requirements ease, which should reduce overall system demand and lessen the intensity of peak load risk compared with the cold start.

The wind generation forecast will interact with this temperature-driven demand shift by influencing how much net load PJM must serve with dispatchable resources. During the colder phase, strong wind output can provide meaningful relief by offsetting part of the increased heating load. As temperatures warm and demand pressure declines, wind variability becomes less of a stress factor, though weaker wind periods could still tighten conditions if they coincide with remaining peak hours. Overall, improving temperatures reduce the demand burden, making the system less dependent on consistently high renewable output.

AG2’s PJM load forecast reflects this transition, with higher demand levels early in the colder portion of the outlook followed by a gradual softening as temperatures trend warmer. Daily peaks remain present throughout, but the magnitude of those peaks is expected to ease as heating load fades. This shift from cold-driven demand strength toward more moderate conditions suggests PJM will move from a higher-risk peak demand environment into a more balanced supply-demand outlook later in the forecast window.

Key takeaways from the January 2026 review:

Pattern: Overall a -NAO month with higher heights to the north-east of Europe with lower heights elsewhere.

Temps: Below normal temperatures across central and north-eastern Europe – coldest anomalies to the north-east. Nearer normal to the west, above normal to the south-east

Hydro: Drier north-eastern Europe, wetter than normal elsewhere.

Wind: Windiest southern Europe. Lower winds north.

Solar: Mostly below normal, except slightly above to the north-east.

C3S verification: Poor forecast with above normal temperatures forecast widely, highest anomalies to the north-east.

The NAO index through January is shown below. A -NAO initially to begin the month quickly trended to near neutral to mid month before then a downwards trend back to -NAO values through the second half of the month.

The 500mb geopotential height anomalies and corresponding temperature anomalies for the month of January are shown below. Overall, a -NAO due to higher heights across Greenland/Iceland. However, troughing dominated Europe, centred across the north-west, while higher heights were observed across north-eastern Europe. A very colder month across north-eastern Europe with temperatures well below the climatological normal here. Temperatures were nearer normal across western Europe, while above normal temperatures were observed across the south-east.

With regards to precipitation, drier conditions were observed to the north-east, with wetter conditions across western and southern Europe.

While for winds, the windiest conditions were across southern Europe with lower winds across the north.

Outgoing Longwave Radiation (OLR) is used here as a proxy for solar. A small region of positive solar generation anomalies (blues/purples from positive OLR) can been seen across north-eastern mainland Europe. While negative anomalies (warmer colours from negative OLR anomalies) were observed across western and southern Europe under cloudier skies here.

Now looking back at how well the C3S model forecast the month of January. Generally lower pressure was forecast to the north-west of Europe with higher pressure forecast to dominate elsewhere across much of Europe. When in reality, low pressure dominated across much of the continent. A poor forecast in terms of temperatures with the C3S model forecasting widely above normal temperatures while actual anomalies were the opposite of this, with the coldest anomalies to the north-east.

With more tamed cold risks coming from the stratosphere in February (more likely due to the lack of coupling with the troposphere), a more linear and reliable MJO signal could set us up for colder risks in March. We should monitor any slower downward propagation from the stratosphere, as it could align with that potentially colder MJO forcing in March.

In the light of recent events, the MJO is continuing to prove itself a very reliable predictor/driver in the sub-seasonal space this winter.

The recent fervent pulse of tropical convection over the W Hem, currently proceeding into Africa has triggered spells of cold weather across many high energy demand regions of the N Hem. The expectations for it to move through the Indian Ocean, Maritime Continent, and W Pac later in February supports the recent milder moves, which are finding less opposition from the stratosphere (https://www.ag2trader.com/1-15days/?blogPostID=189749).

Given the fairly large magnitude of the current MJO wave, we can assume that its rather linear E’ward propagation could bring that train of waves back towards regions where we typically observe a downward forcing to the NAO/AO set of indices (W Hem through Africa) sometime in March (mid-month?). 

Meanwhile, while expectations for quick stratosphere-troposphere coupling are fizzling out for the upcoming SSW event, if we argue that the November SSW event had slow downward propagation through the atmosphere, is there a risk that we could see new forcing from the start towards colder risks again in March?

After shifting more zonal and less blocked, the yesterday’s EC46 run brought back more blocked patters in its higher clusters towards the close of the run, with a “bridge ridge” in the leading position.

In Europe, those top clusters are pretty cold, to mention the lowest one…

Sudden Stratospheric Warming (SSW) events often attract significant attention, especially during winter, because they are sometimes associated with major cold outbreaks in the mid-latitudes. However, SSW-related charts and headlines are frequently misinterpreted. This article aims to clarify what common SSW diagnostics actually indicate — and what they do not.

SSW Does Not Automatically Mean Immediate Surface Impacts

An SSW is primarily a stratospheric phenomenon, characterized by a rapid warming of the polar stratosphere and a weakening or reversal of the zonal mean westerly winds near 10 hPa at high latitudes.

Crucially, the occurrence of an SSW does not imply an immediate impact on surface weather. While some SSWs are followed by notable tropospheric responses, others have little to no detectable influence at the surface. Even when an impact does occur, it typically emerges weeks later, not immediately.

Interpreting the 10 hPa Zonal Wind Ensemble Chart

Charts showing ensemble forecasts of zonal winds at 10 hPa are often used to assess SSW risk. These charts are useful for identifying the probability of a weakening or reversal of the stratospheric polar vortex.

However, they should not be interpreted as direct indicators of surface temperature outcomes. A projected wind reversal at 10 hPa signals an increased likelihood of an SSW event — nothing more.

Will the SSW Signal Propagate Downward?

Whether an SSW affects the troposphere depends on whether its signal propagates downward over time. This is not guaranteed.

One way to assess this potential is by monitoring polar temperature anomaly maps, which can reveal whether stratospheric anomalies are descending from the upper stratosphere toward the lower stratosphere and eventually into the troposphere.

The 12 day national demand change since Friday is +41.9 HDDs…

Modeled temperature anomalies for the next 15 days are below. Modeling offers a colder risk in the East through most of the period now with two distinct peaks – the first through Jan 20, and the second Jan 23-30. This second shot is mostly due to the EPO trending more (-) allows the ceiling to end January to rise quite a bit.

Our period maps are below noting very cold changes compared to Friday.

Changes since Friday, by day, are below for the next 12 days.

The stronger push of cold into Texas is driving a lot of these changes, in addition to the colder Midwest and Northeast trends. Look at these forecast changes in ERCOT since Friday.

HDDs rebound with two distinct peaks – the first through Jan 20, and the second Jan 23-30. There is a high chance we see a few 40 HDD days during the second peak, with our forecast offering multiple now. The 11-15 day sees HDDs slowly return closer to the 30 year normal as the EPO trends back positive and cold dissipates.

Our January HDD number is up to 938 (!!) given the colder weekend changes.

There is also likely a snowcover bias ongoing with ECMWF data, which is likely the cause of the colder outlook on this suite, by 30+ HDD in some cases. We favor a blend of data at this time.

Looking at day 15, February 2, there is still quite a bit of blocking near the Pole and Greenland, but the -EPO AK ridge is breaking down and being replaced with troughing. The result is a lingering cold in the Northeast, but much of the CONUS is warming.

The week of 2 FEB continues to suggest a marked warmer transition, but notice the week of 9 FEB is colder with more blocking again. We will continue to monitor.