Released November 24, 2025 | SUGAR LAND
en
Written by Aaron Studwell for Industrial Info Resources (Sugar Land, Texas)
Click on the image at right for the NERC Winter Reliability Risk Area Map.
Click on the image at right for the NOAA ENSO Ensemble Outlook.
Interaction between La Niña, an easterly Quasi-Biennial Oscillation (QBO), and a strongly disrupted stratospheric polar vortex (SPV) will yield a major early-season weakening of the polar vortex, which is expected to favor high-latitude blocking. Our analysis of analog winter seasons with a weak to moderate La Niña and a weakened or disrupted SPV highlight vertically coupled ridging over Arctic Canada.
Shifts to negative North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) phases will promote cold outbreaks into central and eastern North America, especially in December and January. The net result is a tale of two winters: early-season blocking and subsequent Arctic intrusions superimposed on a weak La Niña base state that still tends to keep the southern tier relatively warm and dry over the DJF mean.
Temperature Outlook Industrial Info's seasonal temperature outlook for DJF keeps above-normal temperatures favored across much of the southern and southeastern CONUS, while below-normal temperatures will reach from the interior Pacific Northwest through the northern Rockies, northern Plains and western Great Lakes. IIR's analysis leans colder than NOAA's Climate Prediction Center (CPC) in the interior U.S., specifically forecasting for a cold corridor from the Canadian Rockies into the Midwest and Ohio Valley, primarily in December and January.
These atmospheric drivers also intersect with NERC's regional reliability signals. The northern Rockies, northern Plains, and Great Lakes regions, where the outlook supports a colder and stormier DJF, are also areas where NERC flags elevated operational stress during extreme cold due to higher peak-load forecasts and dependence on wind and gas resources that can underperform during Arctic outbreaks. The Electric Reliability Council of Texas (ERCOT) remains particularly sensitive during early-morning high-net-load periods, which align with the timing of the anticipated strongest cold surges during December and January.
For Canada, the analog analysis and La Niña composites favor below-normal temperatures from western Canada across the prairies into central and eastern Canada, with the strongest anomalies early in the season as upper-level blocking patterns set up over northern Canada and Greenland. Coastal British Columbia is more variable, with milder interludes embedded in an active storm track.
Alaska shows a split signal: The CPC highlights warmer-than-normal conditions for western and northern Alaska tied to delayed sea-ice formation, but a slight cold tilt for the Panhandle and parts of southeast mainland Alaska, where troughing is more likely.
Across the southern tier of the contiguous United States (CONUS), there is strong alignment between forecast guidance and analog-season assessments. The outlook favors mild anomalies from the Desert Southwest through Texas, the Gulf Coast, and the Southeast, reflecting a weaker subtropical jet and the broader influence of a weak La Niña. While the three-month average leans warm, this does not rule out significant cold air intrusions reaching the Gulf Coast and Southeast, particularly during periods of high-latitude blocking.
A February warm-up along the East Coast also remains a reasonable scenario. If La Niña persists long enough, a more zonal pattern may briefly re-establish itself, allowing milder Pacific air to expand eastward and moderate temperatures along the I-95 corridor as winter progresses.
Click on the image at right for the IIR Temperature Outlook.
From a precipitation and snowfall standpoint, the enhanced northern-tier storminess and cold-air availability align with NERC's assessment that operational stress increases when wind output drops during Arctic outbreaks and when fuel supply chains tighten. These scenarios increase the likelihood of operators relying on emergency procedures during prolonged cold, especially in regions where storage-based resilience is limited. The combination of an active polar jet, upper-level blocking and regionally stressed fuel systems underscores the potential for impactful snow and ice events to amplify grid vulnerability.
When that wetter northern-tier signal is combined with a more blocked, colder regime, above-average snowfall is expected across the northern Rockies and around the Great Lakes, with an active polar jet supporting frequent clipper-type systems and lake-effect events. When the strong Arctic flow extends across the Southeast, barotropic development offshore from the region could lead to Nor'Easter development and subsequent wintry impacts east of the Appalachians.
For the interior South, a weaker subtropical jet and suppressed Gulf storm track argue for fewer classic Gulf lows and more stretches of dry, breezy weather, especially from the southern High Plains to the Southeast Coast.
Across Canada, the same jet configuration favors stormier, wetter conditions along the British Columbia coast and into the adjacent mountains, with near- to above-normal precipitation across portions of the Prairies and Great Lakes corridor, and more mixed signals in Atlantic Canada where blocking details will determine storm tracks.
Click on the image at right for the IIR Precipitation Outlook.
Finally, the winterization standards newly approved by the Federal Energy Regulatory Commission (FERC) will be in effect for the first time this season, requiring generator freeze‑protection upgrades and more robust cold‑weather preparedness. These measures should help mitigate some risks during the early‑season cold regime, particularly during the December-January window, when blocking and stratospheric disruption signals are strongest.
The main forecast uncertainty is how long the high-latitude blocking and weakened polar vortex persists. If blocking verifies through much of January, the season could verify colder than the forecast guidance alone from the Canadian Rockies to the Mid-Atlantic. Additionally, if La Niña trends toward a neutral state by February, bringing a more zonal pattern, warmth along the East and Gulf coasts may temper seasonal anomalies.
Either way, North American winter 2025-26 is unlikely to be uniformly mild or quiet, but instead a highly regional, regime-driven season where timing of cold shots and storm tracks could matter more than the seasonal averages.
Key Takeaways
About Industrial Info Resources
Industrial Info Resources (IIR) is the leading provider of industrial market intelligence. Since 1983, IIR has provided comprehensive research, news and analysis on the industrial process, manufacturing and energy related industries. IIR's Global Market Intelligence (GMI) platform helps companies identify and pursue trends across multiple markets with access to real, qualified and validated plant and project opportunities. Across the world, IIR is tracking more than 200,000 current and future projects worth $17.8 trillion (USD).
Summary
The winter of 2025-26 is expected to develop under a weak, short-lived La Niña that gradually transitions toward neutral conditions by early spring 2026. This pattern, combined with an early-season weakened polar vortex and intermittent high-latitude blocking, favors a colder-than-normal start across western Canada, the northern U.S., and into the Ohio Valley, while the Desert Southwest, Gulf Coast, and Southeast trend warmer.NERC Assessment
The North American power grid enters the season with a distinct set of reliability considerations. According to the North American Electric Reliability Corporation's (NERC) 2025-2026 Winter Reliability Assessment, nearly all assessment areas report year-on-year demand growth, with winter peak demand rising by more than 20 gigawatts (GW). Although resource additions continue, mainly from batteries and modest new gas capacity, supply growth lags demand, leaving several regions more sensitive to prolonged cold snaps. Extreme and persistent Arctic outbreaks could push systems into emergency conditions, especially where natural-gas-fired generation becomes fuel-limited during surges in heating demand.Large-Scale Climate Drivers
The National Oceanic and Atmospheric Administration's (NOAA)s latest El Niño-Southern Oscillation (ENSO) Diagnostics Discussion maintains a La Niña Advisory, with Niño-3.4 SST anomalies in the weak cold range and ensemble guidance showing a 50-55% probability of La Niña through the December-January-February (DJF) period 2025-26, before an ENSO-neutral phase becomes more likely in early 2026. This places Industrial Info's outlook in a regime where ENSO still influences the pattern, but does not fully lock it in.Interaction between La Niña, an easterly Quasi-Biennial Oscillation (QBO), and a strongly disrupted stratospheric polar vortex (SPV) will yield a major early-season weakening of the polar vortex, which is expected to favor high-latitude blocking. Our analysis of analog winter seasons with a weak to moderate La Niña and a weakened or disrupted SPV highlight vertically coupled ridging over Arctic Canada.
Shifts to negative North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) phases will promote cold outbreaks into central and eastern North America, especially in December and January. The net result is a tale of two winters: early-season blocking and subsequent Arctic intrusions superimposed on a weak La Niña base state that still tends to keep the southern tier relatively warm and dry over the DJF mean.
Temperature Outlook Industrial Info's seasonal temperature outlook for DJF keeps above-normal temperatures favored across much of the southern and southeastern CONUS, while below-normal temperatures will reach from the interior Pacific Northwest through the northern Rockies, northern Plains and western Great Lakes. IIR's analysis leans colder than NOAA's Climate Prediction Center (CPC) in the interior U.S., specifically forecasting for a cold corridor from the Canadian Rockies into the Midwest and Ohio Valley, primarily in December and January.
These atmospheric drivers also intersect with NERC's regional reliability signals. The northern Rockies, northern Plains, and Great Lakes regions, where the outlook supports a colder and stormier DJF, are also areas where NERC flags elevated operational stress during extreme cold due to higher peak-load forecasts and dependence on wind and gas resources that can underperform during Arctic outbreaks. The Electric Reliability Council of Texas (ERCOT) remains particularly sensitive during early-morning high-net-load periods, which align with the timing of the anticipated strongest cold surges during December and January.
For Canada, the analog analysis and La Niña composites favor below-normal temperatures from western Canada across the prairies into central and eastern Canada, with the strongest anomalies early in the season as upper-level blocking patterns set up over northern Canada and Greenland. Coastal British Columbia is more variable, with milder interludes embedded in an active storm track.
Alaska shows a split signal: The CPC highlights warmer-than-normal conditions for western and northern Alaska tied to delayed sea-ice formation, but a slight cold tilt for the Panhandle and parts of southeast mainland Alaska, where troughing is more likely.
Across the southern tier of the contiguous United States (CONUS), there is strong alignment between forecast guidance and analog-season assessments. The outlook favors mild anomalies from the Desert Southwest through Texas, the Gulf Coast, and the Southeast, reflecting a weaker subtropical jet and the broader influence of a weak La Niña. While the three-month average leans warm, this does not rule out significant cold air intrusions reaching the Gulf Coast and Southeast, particularly during periods of high-latitude blocking.
A February warm-up along the East Coast also remains a reasonable scenario. If La Niña persists long enough, a more zonal pattern may briefly re-establish itself, allowing milder Pacific air to expand eastward and moderate temperatures along the I-95 corridor as winter progresses.
Precipitation Outlook and Snowfall Signals
The DJF precipitation outlook shows a familiar La Niña-type dipole. Above-normal precipitation is expected from the Pacific Northwest and northern California, extending across the northern Rockies and northern plains into the western Great Lakes. Below-normal precipitation is most likely across the southern tier from the Southwest through southern Texas and the Southeast.From a precipitation and snowfall standpoint, the enhanced northern-tier storminess and cold-air availability align with NERC's assessment that operational stress increases when wind output drops during Arctic outbreaks and when fuel supply chains tighten. These scenarios increase the likelihood of operators relying on emergency procedures during prolonged cold, especially in regions where storage-based resilience is limited. The combination of an active polar jet, upper-level blocking and regionally stressed fuel systems underscores the potential for impactful snow and ice events to amplify grid vulnerability.
When that wetter northern-tier signal is combined with a more blocked, colder regime, above-average snowfall is expected across the northern Rockies and around the Great Lakes, with an active polar jet supporting frequent clipper-type systems and lake-effect events. When the strong Arctic flow extends across the Southeast, barotropic development offshore from the region could lead to Nor'Easter development and subsequent wintry impacts east of the Appalachians.
For the interior South, a weaker subtropical jet and suppressed Gulf storm track argue for fewer classic Gulf lows and more stretches of dry, breezy weather, especially from the southern High Plains to the Southeast Coast.
Across Canada, the same jet configuration favors stormier, wetter conditions along the British Columbia coast and into the adjacent mountains, with near- to above-normal precipitation across portions of the Prairies and Great Lakes corridor, and more mixed signals in Atlantic Canada where blocking details will determine storm tracks.
Closing Thoughts
Taken together, the November ENSO update, partnered with our analog-based guidance, depict a winter with genuine risk for early-season cold and frequent northern-tier storminess, especially from western Canada into the northern and central U.S. At the same time, the southern tier of the United States still leans toward a milder, drier DJF mean, in line with a weak La Niña and a less active subtropical jet.Finally, the winterization standards newly approved by the Federal Energy Regulatory Commission (FERC) will be in effect for the first time this season, requiring generator freeze‑protection upgrades and more robust cold‑weather preparedness. These measures should help mitigate some risks during the early‑season cold regime, particularly during the December-January window, when blocking and stratospheric disruption signals are strongest.
The main forecast uncertainty is how long the high-latitude blocking and weakened polar vortex persists. If blocking verifies through much of January, the season could verify colder than the forecast guidance alone from the Canadian Rockies to the Mid-Atlantic. Additionally, if La Niña trends toward a neutral state by February, bringing a more zonal pattern, warmth along the East and Gulf coasts may temper seasonal anomalies.
Either way, North American winter 2025-26 is unlikely to be uniformly mild or quiet, but instead a highly regional, regime-driven season where timing of cold shots and storm tracks could matter more than the seasonal averages.
Key Takeaways
- A modest, short-lived La Niña is favored to persist through December-February 2025-26, with a transition back to ENSO-neutral most likely in early spring 2026.
- Forecast guidance points to a colder-than-normal early winter from western Canada into the northern U.S. and Ohio Valley, with warmth skewed toward the Desert Southwest, Gulf Coast, and Southeast.
- NERC's 2025-26 Winter Reliability Assessment highlights a 20-GW (2.5%) year-over-year increase in winter peak electricity demand across North America, outpacing resource growth and heightening sensitivity to prolonged Arctic outbreaks.
- Despite adequate resources under normal conditions, NERC identifies elevated risk of supply shortfalls during extreme cold due to natural-gas fuel constraints, regional reliance on variable generation, and uneven winterization practices across the gas-electric system.
About Industrial Info Resources
Industrial Info Resources (IIR) is the leading provider of industrial market intelligence. Since 1983, IIR has provided comprehensive research, news and analysis on the industrial process, manufacturing and energy related industries. IIR's Global Market Intelligence (GMI) platform helps companies identify and pursue trends across multiple markets with access to real, qualified and validated plant and project opportunities. Across the world, IIR is tracking more than 200,000 current and future projects worth $17.8 trillion (USD).
