Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
318 PM EST Tue Nov 08 2022

Valid 00Z Wed Nov 09 2022 - 00Z Fri Nov 11 2022

...Heavy rain and flash flooding threat to persist across parts of
southwestern California this afternoon...

...Heavy mountain snow to continue through Wednesday for the Sierra
Nevada, Intermountain West, and northern Rockies...

...Impacts from Subtropical Storm Nicole expected to begin late today in
eastern Florida...

...Major winter storm impacts possible for portions of the Northern Great
Plains into Northern Minnesota beginning Wednesday

A very active weather pattern continues this afternoon beneath a deep
upper-level low forecast to barrel across the Great Basin this week.
Accordingly, a strong Pacific cold front will traverse the region through
tomorrow, south of a cold Arctic airmass trapped along the spine of the
Rockies. Anomalous Pacific moisture streaming in ahead of the front will
support widespread low-elevation rain and high elevation mixed
precipitation west of the Continental Divide. A flash flooding threat
remains today over portions of Central and Southern California, where a
Moderate Risk (level 3/4) is in effect over the Transverse Ranges of
Southern California. Numerous instances of flash flooding are possible
within the Moderate Risk as 2-3 inches of rainfall (locally higher) fall
atop sensitive terrain and burn scars. Atop the terrain, a swath of Winter
Storm Warnings are also in effect over the Sierra Nevada and Transverse
Ranges through Wednesday.

As the storm system kicks east over the Great Basin tomorrow, the heavy
rainfall threat will wind down, transitioning to a wintry weather threat
over portions of the Northern Rockies southward into the Wasatch where a
smattering of Winter Storm Warnings, Winter Storm Watches, and Winter
Weather Advisories are in effect through tomorrow night. The main show for
significant winter weather looks to begin tomorrow as low pressure
strengthens in the lee of the Rockies ahead of the upper-low approaching
from the west. This system is expected to spin up into a full-fledged
winter storm by Thursday, likely bringing a swath of heavy snow, and a
corridor of sleet and freezing rain, to portions of the northern High
Plains, Great Plains, and Upper-Mississippi River Valley late Wednesday
through Friday. Major winter storm impacts could occur over portions of
the central Dakotas by Thursday as heavy banded snow (likely exceeding 8")
combines with strong gusty winds to yield periods of blizzard conditions.
The greatest risk of freezing rain accumulations right now appears to be
south and east of the highest snowfall axis into north-central Minnesota.
However, uncertainty remains regarding the exact timing and location of
the storm track which has significant ramifications for where the most
impactful wintry precipitation will occur. Interested parties are
encouraged to monitor the forecast as more information becomes available.
In the wake of the system, cold Arctic air filtering down the Plains will
bring much below normal temperatures (15-25 degree below normal highs) to
the Heartland, which look to spread eastward looking ahead to the weekend.

In the Southeast, Tropical Storm Nicole continues to approach the Florida
peninsula and is forecast to strengthen to a Hurricane by Wednesday
evening. The center of the storm is expected to make landfall along the
east coast of Florida late Wednesday/early Thursday, then track northwest
across the state before curving to the northeast and moving up along the
East Coast by the weekend. Nicole is a large storm, and hazardous weather
conditions will extend outside of the current NHC forecast cone. Hurricane
conditions are expected across portions of the southeast and east-central
Florida beginning late Wednesday/Wednesday night, where Hurricane Warnings
are in effect. Tropical storm conditions, and a dangerous storm surge with
damaging waves are expected as far west as coastal Georgia. Heavy rainfall
is expected to begin tomorrow across eastern Florida (Slight Risk or
threat level 2/4), before the flash flooding threat (level 2/4) spreads
north into southeast Georgia and the Mid-Atlantic Thursday. See
nhc.noaa.gov for the latest information regarding Tropical Storm Nicole.

Asherman/Dolan


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