Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
316 PM EST Tue Nov 30 2021

Valid 00Z Wed Dec 01 2021 - 00Z Fri Dec 03 2021

...Widespread record breaking temperatures likely from Northwest into
Great Plains through Thursday; Elevated Fire Weather Risk for Southern
California...

...Atmospheric river to maintain moderate to heavy rainfall over portions
of the Pacific Northwest through Wednesday morning; elevated flood and
debris flow risk...

...Light rain and snow showers over portions of the Great Lakes and
Northeast through midweek...

High pressure dominance in the West will contribute to record breaking
mild weather to begin December. High temperatures 30-40 degrees above
average will build across the West into the Northern Plains Wednesday
before spreading into the Southern Plains Thursday. Ultimately,
temperatures this warm translate to Spring-like highs in the 60's and
mid-low 70's. Hazardous gusty winds associated with the rapid warm-up are
possible through Wednesday along the lee of the Rockies in West-Central
Montana, where High Wind Warnings and Watches are in effect. Moreover, the
abnormally warm weather may exasperate fire weather conditions in Southern
California, where the Storm Prediction Center highlights an Elevated Risk
of fire weather today and tomorrow as dry offshore flow takes hold.
Looking ahead to the beginning of the weekend, the record warmth is
forecast to moderate somewhat as it spreads toward the Southeast, although
a few high temperature records may be threatened on Thursday in the South.

Meanwhile, the very wet weather continues across the Pacific Northwest. An
ongoing Atmospheric River event is forecast to begin winding down this
evening into tomorrow, although an additional 3 to 5 inches of rainfall
are possible in higher elevation areas atop inundated soils. The
additional heavy rain atop increasingly hydrophobic terrain will support
an elevated floods and debris flow risk across Northwest Washington, where
Flood Watches are in effect through Thursday morning. In contrast with the
Northwest, the rest of the Lower 48 is forecast to remain relatively quiet
precipitation-wise through this week. A pair of low pressure systems
traversing southern Canada will produce light to isolated moderate snow
downwind of the Great Lakes and interior Northeast over the next couple of
days. General totals are forecast to remain below a couple inches, but
areas downwind of Lake Ontario may see upwards of 3-5 inches through
Wednesday morning where a small Winter Weather Advisory remains. Some rain
may get mixed in as the warm front associated with the second, more
organized system moves into the Great Lakes on Wednesday night. Shower
activity may develop as far south as the Ohio Valley and Central
Appalachians as the quasi-stationary front sags into the area on Wednesday
morning.


Asherman/Kebede

Graphics are available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php