Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
343 AM EDT Fri Sep 17 2021

Valid 12Z Fri Sep 17 2021 - 12Z Sun Sep 19 2021

...Post-Tropical Cyclone Nicholas will continue to bring a threat of
locally heavy rain and flash flooding to portions of the Gulf Coast states
over the next couple of days...

...A strong cold front and accompanying plume of deep moisture will bring
windy conditions and heavy rains to the Northwest beginning Friday...

...Very warm, windy, and dry conditions will support widespread elevated
fire weather conditions from the Great Basin to the northern High Plains
Friday and Saturday...

Post-Tropical Cyclone Nicholas will continue to slowly drift north and
weaken over the lower Mississippi Valley over the next couple of days. 
The system is expected to produce additional periods of heavy rain along
the central Gulf Coast into portions of the lower Mississippi Valley and
the Southeast.  Flash flooding impacts, especially in urban areas, are
possible across these areas.  Even as the system dissipates, ample
moisture will remain in place -- supporting showers and thunderstorms
across the region through the weekend.

Wet weather is also likely for portions of the Northwest as a strong cold
front and an accompanying plume of deep moisture slides into the region on
Friday.  Windy conditions are expected across western Washington as the
system moves into the region, with heavy rain beginning to develop by late
Friday and continuing into early Saturday. The front will continue to push
farther south and east on Saturday, with heavy rain spreading south into
western Oregon.  Lighter amounts are expected farther east into the
northern Rockies.  Even with the front pushing well east of the region,
unsettled weather will continue across the Northwest through the weekend,
with even an isolated thunderstorm possible across western Washington and
Oregon Saturday and Sunday.  Storm total amounts of 2-4 inches, with
locally heavier amounts, are expected across western Washington and
Oregon, with the heaviest totals likely along the Olympic Peninsula,
coastal ranges, and the Cascades. 

Ahead of the system, windy, dry conditions and above-normal temperatures
are expected to support widespread elevated fire weather concerns across
portions of the Great Basin, northern Sierra, and the northern Rockies and
High Plains on Friday and Saturday -- with Red Flag Warnings in effect for
much of the region.  Temperatures are expected to surge well into the 90s
-- more than 20 degrees above normal -- across portions of the northern
High Plains on Saturday.

Pereira

Graphics are available at www.wpc.ncep.noaa.gov/basicwx/basicwx ndfd.php