Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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516 FXUS21 KWNC 221844 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EST November 22 2025 SYNOPSIS: Strong mid-level low pressure extending from northern Canada into the southwestern Contiguous U.S. (CONUS) is favored to usher Arctic air deep into the Great Plains, potentially resulting in the first freeze of the season for portions of the Southern Plains. Persistent mid-level low pressure across the West increases the likelihood of heavy snow for high elevations across the Northern and Central Rockies. A variety of hazardous weather including heavy precipitation, high winds and heavy snow are also possible for portions of the Great Plains, much of the Mississippi Valley and across parts of the Upper Midwest and Northeast as several low pressure systems and associated fronts form downwind of the Rockies. Deep and persistent surface low pressure over the Bering Sea results in potentially hazardous winds for the Aleutians and coastal portions of southwestern Alaska. HAZARDS Moderate risk of heavy snow for much of the Central Rockies, Sun-Tue, Nov 30-Dec 2. Slight risk of heavy snow for much of the Northern Plains, Great Lakes, and northern New England, Sun-Wed, Nov 30-Dec 3. Slight risk of heavy snow across the Rocky Mountains, Sun-Thu, Nov 30-Dec 4. Moderate risk of heavy precipitation for portions of the Lower and Middle Mississippi and western Tennessee Valleys, Sun-Tue, Nov 30-Dec 2. Slight risk of heavy precipitation for much of the Lower and Middle Mississippi Valley, as well as portions of the Tennessee and Ohio Valleys and eastern Southern and Central Plains, Sun-Thu, Nov 30-Dec 4. Slight risk of much below-normal temperatures for portions of the Desert Southwest, Southern Plains, and Lower Mississippi Valley, Mon-Fri, Dec 1-5. Slight risk of high winds for much of the Great Plains and Mississippi Valley, Sun-Tue, Nov 30-Dec 2. Slight risk of high winds for the Aleutian Islands, Alaskan Peninsula, and along the coastline of Bristol Bay, Sun-Wed, Nov 30-Dec 3. Flooding possible for portions of the Lower Mississippi Valley and the Arklatex region. DETAILED SUMMARY FOR TUESDAY NOVEMBER 25 - SATURDAY NOVEMBER 29: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR SUNDAY NOVEMBER 30 - SATURDAY DECEMBER 06: Model ensembles from the GEFS, ECENS, and CMCE have come into much better agreement with regard to synoptic conditions over the week-2 period. Solutions for 500-hPa height anomalies indicate deep troughing over the Bering Sea and over the western CONUS, with amplified ridging in between, extending from the North Pacific well into the Arctic Circle. Cold air is favored to move southward as a result, pushing far enough south to potentially bring the season`s first freeze to portions of the Southern Plains and Lower Mississippi Valley. This is well indicated by the Probabilistic Extremes Tools (PETs), which indicate at least a 20% chance of minimum temperatures falling below the 15th climatological percentile and 32F for much of central and northern Texas as well as northern Louisiana and southern Arkansas, areas that have yet to experience their first freeze. Therefore a slight risk of much below-normal temperatures is posted for these regions for Dec 1-5. Much colder temperatures are expected north of this region, however with the season`s first freeze having already occurred no other areas are highlighted for cold weather risks as any minimum temperatures are not expected to fall below advisory or hazard criteria. Today`s model solutions are much more bullish with respect to potentially extreme cold temperatures in the Northern Plains, but there is insufficient model consensus to issue an associated hazard at this time. Model solutions also depict a large frontal/baroclinic zone over the central CONUS supported by deep and persistent mid-level troughing over the West, bringing a variety of potentially hazardous weather to regions from the Rockies to the Northeast. At the outset of week-2 a strong surface low is favored over the North Atlantic, while strong surface high pressure is likely over the southeastern CONUS. Models also indicate cyclogenesis occurring in the lee of the Rockies sometime during the forecast period. These features, all combined and fed with the aforementioned cold air, favor widespread snow across the Northern Tier especially for areas prone to lake-effect snow. A slight risk of heavy snow is posted from the Northern Plains east across the Great Lakes and northern New England for Nov 30-Dec 23. Further snow is possible beyond these days, but confidence is lower regarding accumulation totals. Over the past few days model guidance has come close to warranting a moderate risk of heavy snow to be issued over the Central Plains early in the week-2 period, but there has been insufficient consensus to include in today`s outlook. Models also indicate the potential for heavy precipitation further south, over the Mississippi and Tennessee Valleys. Both the ECMWF and GEFS PETs show at least a 20% chance of 3-day precipitation totals exceeding the 85th percentile and at least 1 inch through the middle of week-2 warranting a slight risk of heavy precipitation for Nov 30-Dec 4. Today`s solutions are very bullish, with uncalibrated probabilities from both the ECMWF and GEFS indicating at least a 20% chance of 3-day precipitation totals exceeding 2 inches during the middle of week-2 and above 60% chances of one inch, warranting a moderate risk of heavy precipitation to be issued for portions of the Lower and Middle Mississippi Valley and western Tennessee Valley valid Nov 30-Dec 2. Given the potential for large rainfall totals over the course of the week and relatively rough regional orography, a risk of flooding is highlighted for most of Arkansas, along with the Arklatex region and western Tennessee. Finally, winds are also likely to be enhanced along and behind this disturbance. ECMWF and GEFS ensemble mean wind speeds exceed 20mph episodically over much of the Great Plains and Mississippi Valley early in the week, further supported by pattern recognition and very strong surface features indicated in model solutions. Therefore a slight risk of high winds is posted for these regions valid Nov 30-Dec 2. Amplified mid-level troughing is favored to settle over the western CONUS, bringing an extended period of snow to much of the Intermountain West. A slight risk of heavy snow is posted for most of the Rockies for Nov 30-Dec 4 where the GEFS PET for snow water equivalent (SWE) indicates at least a 20% chance of 3-day SWE accumulation to exceed the 85th percentile and at least 1 inch through the middle of the forecast period. Uncalibrated probabilities from the ECMWF show chances as high as 40% for 3-day snow accumulations to exceed a foot through the middle of the week for much of the Central Rockies, warranting a moderate risk of heavy snow for the Mountains of Colorado, as well as adjacent Wyoming and New Mexico, valid Nov 30-Dec 2. Models maintain strong surface low pressure and stormy conditions over the Bering Sea through the middle of week-2, resulting in high winds over much of southwestern Alaska. PETs from the ECMWF and GEFS show at least a 20% chance of 3-day maximum wind speeds exceeding 40mph across the coasts of western and southern Alaska. The eastern extent of these enhanced winds might be a little overdone though considering that surface low is favored to remain firmly in place well west of the Alaska coast, likely limiting maximum wind speeds east of the Alaskan Peninsula. A slight risk of high wind is posted for the Aleutian Islands, the Alaskan Peninsula, and north along the coast of Bristol Bay for Mov 30-Dec 3. FORECASTER: Danny Barandiaran $$