Valid Sunday November 23, 2025 to Saturday November 29, 2025
US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM
EST November 15 2025
Synopsis: Mid-level high pressure over
Alaska and mid-level low pressure over the western contiguous U.S. (CONUS) are
both predicted to strengthen early in the week-2 forecast period. Mid-level
high pressure is also forecast across the eastern CONUS. This mid-level pattern
is expected to drive various hazards across the Lower 48 states during the
week-2 forecast, including an inflow of Arctic air, heavy mountain snow, and
gusty winds for portions of the West. Parts of the central and eastern CONUS
may be impacted by heavy precipitation, heavy snow, gusty winds, and flooding.
Hazards - Slight risk of heavy precipitation for eastern
portions of the Southern Plains, Middle and Lower Mississippi Valley, southern
Ohio and Tennessee Valleys, and adjacent parts of the Southeast, Sun-Tue, Nov
23-25, and Fri-Sat, Nov 28-29.
- Slight risk of heavy snow for much of the mountainous West, Sun-Sat, Nov
23-29.
- Slight risk of heavy snow over much of the Northern and Central Plains and
Upper Mississippi Valley, Wed-Sat, Nov 26-29.
- Slight risk of much below-normal temperatures across much of the western
half of the CONUS, Tue-Sat, Nov 25-29.
- Slight risk of high winds over most of the CONUS, Sun-Sat, Nov 23-29.
- Flooding possible in the general vicinity of the Arklatex.
Detailed SummaryFor Tuesday November 18 - Saturday
November 22:
WPC Days 3-7 U.S.
Hazards For Sunday November 23 -
Saturday November 29: Early in the week-2 period, an amplifying mid-level
ridge over Alaska is expected to contribute to the deepening of a mid-level
trough downstream over the western CONUS. This scenario is predicted to bring
anomalously warm air to Alaska and anomalously cold Arctic air to the western
Lower 48 states. Significantly anomalously warm temperatures predicted in
southwestern Alaska favors precipitation in the form of rain rather than snow
for many areas, which could lead to a number of hazardous impacts including
coastal erosion, flooding, and a decrease in the stability of ice on rivers and
lakes. For the western CONUS, temperatures are expected to fall below 20 deg F
in many areas, and a hard freeze (28 deg F) is a significant concern for
near-coastal areas of the Pacific Northwest, including Seattle and Portland.
These minimum temperatures could bring an end to the growing season across
Oregon's Willamette Valley, and are supported by 0z runs of the ECENS and GEFS.
A slight risk of much below-normal temperatures is favored across much of the
western half of the CONUS, Nov 25-29.
As the mid-level trough deepens across the West and progresses slowly
eastward, a slight risk for heavy snow is posted for much of the mountainous
West, Nov 23-29. This is consistent with raw (uncalibrated) snowfall guidance
from the ECENS and (to a lesser extent) the GEFS, with predicted snowfall
totals in excess of 6 inches, and locally a foot or more in the highest
elevations. Broad cyclonic curvature and cold air aloft is expected to maintain
the necessary instability to generate significant snowfall across the West,
substantially boosting mountain snowpacks in the process. In addition to the
predicted arctic air and heavy snow hazards across the West, increased chances
for gusty winds of 20-30 mph or more are indicated by the ECENS and GEFS
Probabilistic Extremes Tools (PETs) wind guidance. This is further supported by
forecast 10-meter wind speeds from the 0z ECENS ensemble mean, and the
expectation of tighter surface pressure gradients. These tighter pressure
gradients are expected to be near the southern edges of advancing arctic air
masses surging southward across the West. Accordingly, a slight risk of
episodic high winds is favored across most of the Western CONUS for the
duration of week-2.
Over the Central CONUS, leeside cyclogenesis is predicted by the GEFS and
ECENS models, with several surface low pressure centers tracking from the
vicinity of eastern Colorado towards the Upper Great Lakes region, which is a
very common storm track for late November. A slight risk of heavy snow (>85th
historical percentile and 4-6+ inches) is posted for the northern and western
flanks of one of these disturbances as it tracks towards the Upper Great Lakes
region during the second half of the forecast period. This may cause some
travel disruptions for the Thanksgiving holiday. The area expected to be most
affected by this storm system includes the northern and central Great Plains
and portions of the Upper Mississippi Valley. Surface high pressure near or off
the Southeast coast favors an increase in moist southerly return flow and a
slight risk of heavy precipitation across south-central and southeastern
portions of the CONUS as far north as the Ohio Valley, on Nov 23-25. A second
round of heavy precipitation is indicated by multiple numerical models on Nov
28-29, in response to another passing disturbance. Precipitation amounts of at
least 1-inch are forecast (3-day period), and as much as 4-7 inches of
precipitation are predicted for much of this same area during the preceding
week-1 period. As a result, an area of possible flooding is deemed most likely
in the Arklatex region.
For much of the CONUS east of the Rockies, dynamical models indicate
several low pressure systems are anticipated to move through these regions
during the week-2 period, accompanied by gusty northwesterly winds of 20-30
mph. Multiple storm systems affecting the Central and Eastern CONUS at
different times during week-2 necessitates the designation of a very broad area
of episodic high winds. In the Great Lakes region, lake-enhanced precipitation
can be expected in the wake of individual synoptic-scale disturbances. However,
if the arctic air predicted to impact the western CONUS during week-2 moves
across the eastern CONUS after the week-2 period, the colder air streaming over
the relatively warm waters of the Great Lakes will most likely result in
significant lake-effect precipitation for the typical climatological snowbelt
areas downwind of the Lakes.
Forecaster: Anthony Artusa
$$
Please consult local NWS Forecast Offices for short range forecasts and region-specific information.
Resources
Week-2 Probabilistic Extremes Tool
GFS Ensemble Forecasts
www.nws.noaa.gov
