Composite Map Day 8-14

Experimental Probabilistic Outlooks Temperature Hazards Precipitation Hazards Wind Hazards Snow Hazards

Valid Friday January 23, 2026 to Thursday January 29, 2026

US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EST January 15 2026

Synopsis: A developing area of mid-level low pressure over south-central Canada and the western contiguous U.S. (CONUS) increases the risk of multiple weather related hazards including anomalously cold winter temperatures along the northern tier of the CONUS, and high wind and high elevation snow over the Interior West. Surface low development in the lee of the Rockies may potentially trigger heavy precipitation and low elevation heavy snowfall across portions of the Midwest during the period. In the central Pacific, there is an increased chance of Kona low development potentially impacting parts of Hawaii, with enhanced precipitation and occasional high wind gusts.

Hazards

• Moderate risk of much below normal temperatures for northern portions of the Northern Plains, Upper Mississippi Valley, and western Great Lakes, Sat-Mon, Jan 24-26.
• Slight risk of much below normal temperatures for portions of the Northern Intermountain, Northern Rockies, Northern and Central Plains, Upper and Middle Mississippi and Ohio Valleys, Great Lakes, and Northeast, Fri-Thu, Jan 23-29.
• Slight risk of heavy snow for portions of the Great Lakes and Central Appalachians, Fri-Thu, Jan 23-29.
• Slight risk of heavy snow for the higher elevations of the Northern Intermountain, Great Basin and Rockies, Fri-Mon, Jan 23-26.
• Slight risk of heavy snow for portions of the Plains, Mississippi and Ohio Valleys, Great Lakes, Mid-Atlantic, and the Northeast, Fri-Sun, Jan 23-25.
• Slight risk of high winds for much of the Interior West, Fri-Mon, Jan 23-26.
• Moderate risk of heavy precipitation for portions of the Middle and Lower Mississippi, Ohio and Tennessee Valleys, and Southern Appalachians, Fri-Sat, Jan 23-24.
• Slight risk of heavy precipitation for parts of the Mississippi, Ohio, and Tennessee Valleys, Appalachians, and Southeast, Fri-Sun, Jan 23-25.

Detailed Summary

For Sunday January 18 - Thursday January 22: WPC Days 3-7 U.S. Hazards

For Friday January 23 - Thursday January 29: There has been decent consistency in the GEFS and ECMWF ensemble mean 500-hPa height forecasts favoring a strong mid-level ridge entrenched over the north Pacific and the Bering Sea during the period, with a retrograding mean trough over southern Canada and into the western U.S., and rising heights over the southeastern U.S. by late next week. This mid-level pattern continues to be favorable for the advection of Arctic air where there is an elevated risk of much below normal temperatures primarily over north-central CONUS, with this threat potentially shifting eastward later in week-2. Moreover, the mean troughing over the Interior West remains favorable for the ejection of shortwave disturbances downstream, where predicted surface low development in the lee of the Rockies continues to support an increased risk of heavy precipitation and snowfall over parts of the Great Plains, Mississippi, Tennessee and Ohio Valleys. Compared to yesterday, there are a few notable model differences with the evolving mid-level pattern which is contributing to added uncertainty in the hazards outlook. The ECMWF features a stronger trough anomaly center over south-central Canada, leading to a colder temperature response, as well as a stronger southward push of the cold air into the Plains and Mississippi Valley through the middle of the period. By contrast, the GEFS is generally weaker with the trough and the resultant cold potential, but features a deeper trough axis into the southwestern CONUS bringing wetter conditions over the lower Four Corners region and the Desert Southwest. Lastly, while more mid-level ridging is favored to develop across the western U.S. later in week-2, the ECMWF features a mid-level mean trough encroaching the Pacific Northwest and British Columbia signaling the return of enhanced onshore flow late in week-2. While the GEFS depicts this mid-level feature over the eastern Pacific as well, it maintains more of a full latitude ridge over western North America resulting in comparably drier conditions over the West Coast by late January.

Over the northern tier of the CONUS, strong mean surface high pressure and accompanying Arctic air is favored to descend southward from the Canadian Prairies early in week-2, where the ECMWF depicts more of a southward and eastward expanse of this surface feature compared to the GEFS. These discrepancies are well reflected in the Probabilistic Extreme Tools (PETs), as the GEFS and ECMWF have trended away from one another in regards to the strength and coverage of the cold potential since yesterday. While the GEFS limits 20% chances of minimum temperatures falling below the 15th percentile much closer to the Canadian border compared to ECMWF, it is notable that the 10% chances in the GEFS extend well to the south into the Southern Plains and Mississippi Valley. This represents at least some ensemble support and consistency with the southern reach of anomalous cold in the ECMWF PET where higher (20-30%) chances are indicated. Therefore, the slight risk area of much below normal temperatures is adjusted to cover more of the Plains, as well as the Mississippi and Ohio Valleys in the updated outlook. The coldest signals in the PETs remain established across the Upper Midwest and northern Great Lakes, with the ECMWF becoming supportive of high risk hazard designation, now depicting 50-60% chances for minimum temperatures falling below the 15th percentile. However, the warmer GEFS shows a more limited area with 30% chances, and to reconcile these differences, a moderate risk of much below normal temperatures remains issued for Jan 24-26. Within the highlighted region, the uncalibrated ECMWF continues to depict 30-40% chances for wind chill values to fall below -40deg F. As the mid-level troughing shifts eastward by middle of week-2, so does the cold signals in the PETs, though the GEFS becomes much more washed out. This precludes any expansion of the moderate risk area at this time, but this potential will continue to be monitored in upcoming hazard outlooks. Due to the potential for one or more shots of cold air over the northern tier, the combination of pure lake effect snow and/or lake enhanced snow over the Great Lakes, supports the continuation of a slight risk of heavy snow downwind of the Lakes and into the Central Appalachians for all of week-2.

The transition towards more mid-level troughing (ridging) the western (eastern) CONUS continues to support surface low development in the lee of Rockies with moist return flow from the Gulf of America increasing the likelihood of heavy precipitation. Good agreement exists in daily precipitation tools depicting enhanced totals over the Ohio and Tennessee Valleys early in the period. Similar to the past few days, PETs still lean towards a slight risk designation, but deference is given to the more recently skillful raw precipitation tools, which highlight 30-60% chances for 3-day amounts exceeding an inch over this part of the country. Based on this, and good run-to-run continuity in the timing of the heavy precipitation threat, a corresponding moderate risk area remains issued for Jan 23-24. Within this moderate risk area, localized flash or small stream flooding is possible during the period. A broader slight risk area remains posted for Jan 23-25, where PETs depict 20-30% chances for 3-day amounts exceeding the 85th percentile and 1 inch.

With the aforementioned anomalous cold air expected to dig southward from the northern tier of the CONUS, any enhanced moisture being entrained into a frontal system is expected to be conducive for accumulating snowfall along the backside of the tracking surface low. Although the uncalibrated ECMWF and GEFS are not quite supportive of snowfall amounts reaching hazards criteria, a slight risk of heavy snow is posted for much of the Midwest for Jan 23-25 based on the predicted baroclinicity in the region and several deterministic solutions. Relative to yesterday, this slight risk area is also expanded further to the south in the Plains and Mississippi Valley based on the aforementioned southerly solutions of the anomalously cold air, with coverage also including parts of the mid-Atlantic and Northeast based on increased snowfall signals associated with the storm track. Mixed wintry precipitation is possible along/near the interface of the slight heavy precipitation and heavy snow risk areas.

Based on continued agreement among the GEFS, ECMWF, and Canadian ensembles in regards to the development of negative height departures over the Interior West, slight risks of high elevation heavy snow and high winds remain posted for the region, valid through Jan 26 before mid-level heights begin to build across the western CONUS later in week-2. Both the Snow Water Equivalent (SWE) and wind PETs maintain increased chances for values exceeding the 85th percentile through the middle of the period. Precipitation based PETs also show increased signals for 3-day amounts exceeding the 85th percentile over portions of southern California and the Desert Southwest early in week-2. However, uncalibrated tools are comparably drier with this potential resulting in no corresponding hazards being issued at this time.

Across the Pacific Northwest, the ECMWF Integrated Vapor Transport (IVT) tool depicts an increasing Atmospheric River (AR) potential towards the backend of week-2 which is supported in the ECMWF PET with 20% chances of 3-day amounts exceeding the 85th percentile and 2 inches from northern California to western Washington during days 12-14. The GEFS IVT is beginning to show some signal, but the GEFS PET is void of any precipitation threat. As a result, no associated hazards are posted, but this potential will be reassessed as any AR related risks may come into better focus.

No hazards are issued over Alaska. The strong ridging over the north Pacific and into the Mainland remains favorable for the above-normal temperatures with a tilt in the odds for above-normal precipitation. Should the mid-level ridge axis remain amplified and shift westward, this would allow for more cross polar flow with colder temperatures developing across the Mainland and any temperature trends will continue to be monitored.

With persistent troughing favored underneath strong ridging forecast over the northern Pacific, one or more Kona lows may develop and impact parts of Hawaii during week-2. There is considerable uncertainty regarding the location, evolution, and magnitude of any hazardous conditions, but there is general agreement that precipitation over most of the state will be above normal for week-2. Potential impacts include periods of heavy precipitation, high winds, and significant waves.

Forecaster: Nick Novella

$$ Please consult local NWS Forecast Offices for short range forecasts and region-specific information.

Resources

Week-2 Probabilistic Extremes Tool

GFS Ensemble Forecasts