760 
FXUS21 KWNC 191802
PMDTHR
US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EDT September 19 2025

SYNOPSIS: Model ensembles favor a transition from an amplified wave train in 
mid-level pressure to a more flattened pattern, resulting in few concerns from 
a hazardous weather perspective. Early in week-2 mid-level low pressure over 
the North Pacific may enhance surface winds along portions of the California 
coast.

HAZARDS

Slight risk of episodic high winds for coastal portions of California from Cape 
Mendocino to Point Conception, Sat-Mon, Sep 27-29.

DETAILED SUMMARY

FOR MONDAY SEPTEMBER 22 - FRIDAY SEPTEMBER 26: 
https://www.wpc.ncep.noaa.gov/threats/threats.php

FOR SATURDAY SEPTEMBER 27 - FRIDAY OCTOBER 03: Todays model solutions for 
500-hPa heights indicate a transition away from an amplified wave train 
stretching over North America to a much more zonal pattern during the week-2 
period, resulting in relatively tranquil weather with few concerns with respect 
to the potential for hazardous weather over the Contiguous U.S. (CONUS). At the 
outset of week-2 guidance continues to depict a fairly deep trough off the West 
Coast. This pattern, in addition to predicted surface high pressure near the 
West Coast and adjacent surface low pressure over West Coast states, may result 
in a tight pressure gradient at the surface and increased likelihood for high 
winds across the West Coast. A slight risk of episodic high winds is 
highlighted for coastal portions of California between Cape Mendocino and Point 
Conception for Sep 27-29, where Probabilistic Extreme Tools (PETs) indicate at 
least a 20% chance of wind speeds exceeding the 85th percentile and 25 mph and 
ensemble mean wind speed from both the GEFS and ECMWF indicate enhanced winds 
for much of the California coast early in week-2. 



In addition to enhanced winds, models depict significant moisture transport 
into the Pacific Northwest as this trough moves into the Interior West. This is 
likely to result in periods of enhanced precipitation for much of the 
northwestern CONUS through the middle of week-2. While low elevation 
accumulations (i.e. rain) are not likely to reach hazardous thresholds, model 
solutions had been indicating the potential of heavy snow across high elevation 
areas of the northern Cascades and Rockies as a colder airmass moves in with 
the trough. Todays model solutions are less bullish with regard to 
sufficiently low temperatures for snow therefore no associated hazard is posted 
at this time.

FORECASTER: Danny Barandiaran 

$$