275
FXUS21 KWNC 251813
PMDTHR
US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EDT October 25 2026

SYNOPSIS: An active weather pattern is anticipated for much of the western
contiguous U.S. (CONUS) during week-2. A series of mid-level lows approaching
the West Coast is predicted to bring periods of heavy precipitation, high
elevation snow, and high winds across coastal areas, shifting from coastal
California and the Four Corners to the Pacific Northwest with time. Low
pressure development in the Plains brings increased chances for heavy
precipitation and high winds to the Plains and Mississippi and Ohio Valleys
early in the period.

HAZARDS

Slight risk of heavy precipitation for portions of the Four Corners, Mon, Nov 2.

Slight risk of heavy snow for parts of the Central Rockies, Mon, Nov 2.

Slight risk of heavy precipitation for coastal portions of southern California,
Mon, Nov 2.

Slight risk of heavy precipitation for portions of the Pacific Northwest and
Northern California, Wed-Sun, Nov 4-8.

Slight risk of heavy snow for the Cascades, Klamath and northern Sierra Nevada
Ranges, Wed-Sun, Nov 4-8.

Slight risk of high winds for coastal portions of the Pacific Northwest,
Wed-Sun, Nov 4-8.

Slight risk of heavy precipitation for parts of the Northern and Central
Plains, Upper and Middle Mississippi Valley, Ohio Valley, and Great Lakes,
Mon-Wed, Nov 2-4.

Slight risk of high winds for parts of the Northern and Central Plains, Upper
and Middle Mississippi Valley, and Great Lakes, Mon-Wed, Nov 2-4.

Flooding Possible for portions of Arizona and adjacent New Mexico.

DETAILED SUMMARY

FOR WEDNESDAY OCTOBER 28 - SUNDAY NOVEMBER 01:
https://www.wpc.ncep.noaa.gov/threats/threats.php

FOR MONDAY NOVEMBER 02 - SUNDAY NOVEMBER 08: Enhanced tropical moisture tied to
mid-level low pressure is forecast to be progressing through the southwestern
CONUS at the end of week-1 and into week-2. Most of this moisture is forecast
to be moving into the Plains by the start of week-2 but some model guidance
continues to indicate lingering precipitation and potential flooding into day
8. Therefore, a slight risk of heavy precipitation remains posted for coastal
Southern California and the Lower Four Corners on Nov 2. A flooding possible
hazard remains posted for portions of Arizona where localized flooding may
linger into early week-2. Finally, a slight risk of heavy snow is posted for
portions of the Central Rockies, again for Nov 2.



As this energy and moisture moves into the Plains, there is agreement for
lee-side cyclogenesis. Tools have trended further north with this development
leading to heavy precipitation and high wind risks shifting north relative to
prior forecasts. The best agreement for heavy precipitation now lies in the
Northern and Central Plains eastward through the Mississippi Valley into the
western Great Lakes and Ohio Valley. Both the GEFS and ECENS uncalibrated
ensembles forecast at least a 30% chance of three day precipitation amounts
exceeding an inch. The GEFS and ECENS Probabilistic Extremes Tools (PETs) are
also supportive of this solution. Therefore, a slight risk of heavy
precipitation is posted for this region for Nov 2-4. A corresponding slight
risk of high winds is posted with support from the PETs and ensemble members
forecasting a low pressure falling into the 990s hPa.



A mid-level trough in the Gulf of Alaska is forecast to move southwest in time
and build off the Pacific Northwest Coast. This may bring a period of prolonged
precipitation chances in the Northwest from the middle of week-2 into week-3.
The PETs indicate 20-40% chances of 3 day precipitation amounts exceeding the
85th climatological percentile and 1.5 inches for days 10-12 and 12-14.
Uncalibrated ensemble guidance indicates similar probabilities. Further
Integrated Water Vapor Transport (IVT) tools highlight increased chances for
elevated moisture into the West Coast by the middle of week-2 continuing into
week-3. Therefore, a slight risk of heavy precipitation is posted for the
Pacific Northwest into Northern California for Nov 4-8. A corresponding slight
risk of heavy snow is posted for the high elevations of the Cascades, Sierra
Nevada, and Klamath ranges. Finally, a slight risk of high winds is from
Northern California through the Pacific Northwest coasts, again for Nov 4-8.



In Alaska, southerly flow around the mid-level low pressure in the Gulf of
Alaska, brings continued chances for precipitation, particularly to Southeast
Alaska. Three day precipitation amounts are unlikely to reach hazardous
criteria at this time but will continue to be monitored.



FORECASTER: Ryan Bolt

$$