360 FXUS21 KWNC 231900 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EST November 23 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. Heavy precipitation 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 a low pressure system and associated front forms downwind of the Rockies. HAZARDS Slight risk of heavy snow for much of the Northern Plains, Great Lakes, and northern New England, Mon-Wed, Dec 1-3. Slight risk of heavy snow across the Rocky Mountains, Mon-Wed, Dec 1-3. Slight risk of heavy precipitation for portions of the Lower and Middle Mississippi Valley, the Tennessee and Ohio Valleys and eastern Southern Plains, Sun-Thu, Mon-Wed, Dec 1-3. Slight risk of much below-normal temperatures for portions of the Desert Southwest, Southern Plains, and Lower Mississippi Valley, Mon-Fri, Dec 1-5. DETAILED SUMMARY FOR WEDNESDAY NOVEMBER 26 - SUNDAY NOVEMBER 30: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR MONDAY DECEMBER 01 - SUNDAY DECEMBER 07: Model ensembles have struggled to maintain a consistent solution on the development of amplified ridging(troughing) over the North Pacific(western CONUS) even as the anticipated event draws nearer. Regardless of the precise timing and intensity of these features, 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. 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 surface low is favored over the Mississippi Valley, while strong surface high pressure is likely over the North Atlantic. 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 Dec 1-3. Further snow is possible beyond these days, but confidence is lower regarding accumulation totals. Models also indicate the potential for heavy precipitation further south, over the Middle Mississippi, Ohio and Tennessee Valleys, although today's solutions indicate lower precipitation totals from this event than in previous days. However, both the ECMWF and GEFS PETs still show at least a 20% chance of 3-day precipitation totals exceeding the 85th percentile and at least 1 inch early in week-2, further supported by pattern recognition of favorable synoptic conditions. Therefore a slight risk of heavy precipitation remains posted, for Dec 1-3. 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 Dec 1-3, 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 early in the forecast period. Similar to the above discussion concerning heavy precipitation, model solutions today are much less bullish with regard to large total accumulations, therefore the moderate risk of heavy snow has been discontinued. FORECASTER: Danny Barandiaran $$