Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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810 FXUS21 KWNC 031901 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EST January 03 2026 SYNOPSIS: There is better agreement today among the various ensemble mean models during week-2. The ECENS, GEFS, and CMCE, support mid-level high pressure over the far eastern Pacific Ocean and western North America, and mid-level low pressure over the eastern contiguous U.S. (CONUS). There is also a weak area of lingering low pressure predicted over the Southwest. Early in the week-2 forecast period, a storm system is forecast to move off the East Coast, accompanied by high winds and areas of heavy snow in the Great Lakes region and Northeast. In the West, persistent surface high pressure forecast over the Great Basin favors gusty downslope winds for southern California. In Alaska, the mid-level height pattern favors significantly wetter conditions over the state, and milder conditions for Southeast Alaska. HAZARDS Slight risk of heavy snow from the Lower Great Lakes region across northern New York state and northern New England, Sun-Mon, Jan 11-12. Slight risk of high winds over much of the Great Lakes, Northeast, and Upper Mid-Atlantic, Sun-Mon, Jan 11-12. Slight risk of high winds over southern California and vicinity, Sun-Sat, Jan 11-17. DETAILED SUMMARY FOR TUESDAY JANUARY 06 - SATURDAY JANUARY 10: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR SUNDAY JANUARY 11 - SATURDAY JANUARY 17: During the first few days of the week-2 forecast period, a broad low pressure system is predicted to move eastward across the East Coast states and western Atlantic. During and after the passage of this low pressure system, there is an increased chance of heavy snow to the lee of the Lower Great Lakes, northern New York, and northern New England. This is supported by raw (uncalibrated) snow amounts from the ECENS and GEFS ensemble mean models and from the AI-version of the ECENS. Accordingly, a slight risk of heavy snow is posted for these areas, valid Jan 11-12. It is worth noting that Lake Erie surface water temperatures are in the 30s, and once the lake surface freezes, the underlying moisture source underneath the ice will be cut off. In addition to the heavy snow hazard, a slight risk of high winds is valid for the same days across most of the Great Lakes region, Northeast, and Upper Mid-Atlantic. A tightened pressure gradient predicted in the mean sea-level pressure fields of the models is forecast to result in wind speeds greater than the 85th historical percentile and 20 mph. This is also warranted by the Probabilistic Extremes Tool (PET) for wind. Over the southeastern quarter of the Lower 48 states, the broad area of favored heavy precipitation the last few days has been removed due to two considerations. One reason is that today`s model guidance (PETs and uncalibrated output) predicts a much smaller area of precipitation amounts that exceed hazardous thresholds, with most of the former area now favored to receive 0.50 - 0.75-inch of rain. A second reason is that northerly (offshore) low-level flow is better indicated by today`s model runs over the Gulf Coast states and the adjacent northern Gulf. This is expected to prevent the return flow of warm, moist Gulf air into the western Gulf region/eastern Southern Plains for an extended period. Over the West, a predicted mid-level ridge and positive 500-hPa height anomalies favor the development of surface high pressure over the Great Basin early in the period. The clockwise circulation of air around this surface high pressure system supports Santa Ana-type downslope winds that flow across southern California from the interior to the Pacific coast. A slight risk of episodic high winds is posted for southern California from Jan 11-17. Typically, this activity would elevate the risk of fire weather. However, the precipitation received over southern California during the previous two-week period (Dec 18-31, 2025) was about 4 times their climatology. This will help to minimize the risk of wildfires. No temperature hazards have been posted on today`s map. For the past several days, there was concern of Arctic air originating from the North Polar region to advect due southward across central Canada into the north-central CONUS, but the agreement between the various models and tools did not provide confident support for a slight risk area of much below-normal surface temperatures. With today`s mid-level height forecasts in better agreement on an amplified West Coast ridge and amplified eastern CONUS trough, the northerly flow in-between leads to increased chances of colder weather for the north-central states. There are no hazards posted for Alaska today. The state is predicted to be sandwiched between a 500-hPa trough over the Bering Sea, and an amplified 500-hPa ridge centered near the West Coast of North America. This flow pattern is very different from the one observed during the last few weeks. Instead of an extended period of bitter cold temperatures, the flow pattern favors increased onshore flow and much wetter conditions over the state, in addition to favored above normal mean temperatures over Southeast Alaska. FORECASTER: Anthony Artusa $$