711
FXUS21 KWNC 212000
PMDTHR
US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EST November 21 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 range of hazardous weather including heavy
precipitation, high winds and heavy snow are also possible for portions of the
Southern Plains, much of the Mississippi Valley and across parts of the Upper
Midwest and Northeast as some of these lows and associated fronts move
northeastward, especially in lake effect-prone regions. 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 the southern and eastern shores of Lakes Erie
and Ontario, northwestern Lower Michigan, and much of Upper Michigan, Sat-Sun,
Nov 29-30.

Moderate risk of heavy snow for much of the Central Rockies, Sat-Mon, Nov
29-Dec 1.

Slight risk of heavy snow for much of the Northern Plains, Great Lakes, and
northern New England, Sat-Tue, Nov 29-Dec 2.

Slight risk of heavy snow across the Rocky Mountains, Sat-Fri, Nov 29-Dec 5.

Moderate risk of heavy precipitation for portions of the Lower and Middle
Mississippi and western Tennessee Valleys, Sun-Wed, Nov 30-Dec 3.

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, Sat-Fri, Nov 29-Dec 5.

Slight risk of much below-normal temperatures for portions of the Desert
Southwest, Southern Plains, and Lower Mississippi Valley, Sun-Fri, Nov 30-Dec 5.

Slight risk of high winds for much of the Southern and Central Rockies as well
as portions of the Desert Southwest, and Southern and Central Plains, Sat-Sun,
Nov 29-30.

Slight risk of high winds for the Aleutian Islands, Alaskan Peninsula, and
along the coastline of Bristol Bay, Sat-Fri, Nov 29-Dec 5.

Flooding possible for portions of the Lower Mississippi Valley and the Arklatex
region.

DETAILED SUMMARY

FOR MONDAY NOVEMBER 24 - FRIDAY NOVEMBER 28:
https://www.wpc.ncep.noaa.gov/threats/threats.php

FOR SATURDAY NOVEMBER 29 - FRIDAY DECEMBER 05: 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
seasons first freeze to portions of the Southern Plains and Lower Mississippi V
alley. This is well indicated by the Probabilistic Extremes Tools (PETs), which
indicate at least a 20% chance of minimum temperatures falling below the 15th cl
imatological percentile and 32F for much of central and northern Texas as well a
s northern Louisiana and southern Arkansas, areas that have yet to experience th
eir first freeze. Therefore a slight risk of much below-normal temperatures is p
osted for these regions for Nov 30-Dec 5. Much colder temperatures are expected
north of this region, however with the seasons first freeze having already occu
rred no other areas are highlighted for cold weather risks as any minimum temper
atures are not expected to fall below advisory or hazard criteria. Todays model
 solutions are much more bullish with respect to potentially extreme cold temper
atures in the Northern Plains, but there is insufficient model consensus to issu
e an associated hazard at this time.



Model solutions also depict a large fron
tal/baroclinic zone over the central CONUS supported by deep and persistent mid-
level troughing over the West, bringing a variety of potentially hazardous weath
er to regions from the Rockies to the Northeast. At the outset of week-2 a stron
g surface low is favored over the North Atlantic, while strong surface high pres
sure is likely over the southeastern CONUS. Models also indicate cyclogenesis oc
curring in the lee of the Rockies sometime during the forecast period. These fea
tures, all combined and fed with the aforementioned cold air, favor widespread s
now across the Northern Tier especially for areas prone to lake-effect snow. A s
light risk of heavy snow is posted from the Northern Plains east across the Grea
t Lakes and northern New England for Nov 29-Dec 2, and a moderate risk of heavy
snow the southern and eastern shore of Lakes Erie and Ontario, as well as much o
f the Upper Peninsula of Michigan and northwestern Lower Michigan, valid Nov 29-
30. Further snow is possible beyond these days, but confidence is lower regardin
g accumulation totals.



Models also indicate the potential for heavy precipit
ation 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 throughout week-2 warranting a slight r
isk of heavy precipitation for Nov 29-Dec 5. Todays solutions are very bullish,
 with uncalibrated probabilities from both the ECMWF and GEFS indicating at leas
t a 20% chance of 3-day precipitation totals exceeding 2 inches during the middl
e of week-2 and above 60% chances of one inch, warranting a moderate risk of hea
vy precipitation to be issued for portions of the Lower and Middle Mississippi V
alley and western Tennessee Valley. Given the potential for large rainfall total
s 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 an
d western Tennessee. Finally, winds are also likely to be enhanced along and beh
ind this disturbance. ECMWF and GEFS ensemble mean wind speeds exceed 20mph epis
odically over much of the Southern Plains as well as the Southern and Central Ro
ckies early in the week. Therefore a slight risk of high winds is posted for the
se regions valid Nov 29-30.



Amplified mid-level troughing is favored to settl
e over the western CONUS, bringing an extended period of snow to much of the Int
ermountain West. A slight risk of heavy snow is posted for most of the Rockies f
or all of week-2 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 throughout the forecast period. Uncalibrated probabilities from
the ECMWF show chances as high as 40% for 3-day snow accumulations to exceed a f
oot 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.



Models maintain strong surface low pressure and stor
my conditions over the Bering Sea throughout week-2, resulting in high winds ove
r 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 litt
le overdone though considering that surface low is favored to remain firmly in p
lace 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 Isl
ands, the Alaskan Peninsula, and north along the coast of Bristol Bay for all of
 week-2.

FORECASTER: Danny Barandiaran

$$