Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
319 PM EST Tue Nov 29 2022

Valid 00Z Wed Nov 30 2022 - 00Z Fri Dec 02 2022

...Heavy snow for the Cascades, Sierra and Northern Rockies...

...There are moderate flash flooding and severe weather threats over
portions of the Lower Mississippi & Tennessee Valleys and Southeast
tonight...


An upper-level trough will move across the Midwest and Northeast over the
next couple of days. An upper low will open into a trough and amplify
while it enters the Northwest.

A deep low pressure system currently moving through the Mississippi Valley
will continue to focus showers and thunderstorms across the region and
points eastward over the next couple of days. The most immediate threats
will come from potential severe thunderstorms and excessive rainfall that
are forecast for portions of the Lower Mississippi Valley, Southeast and
central Gulf Coast tonight. A moderate risk of excessive rainfall leading
to flash flooding is in effect over parts of southern Mississippi,
southwestern Alabama and far western Florida embedded within a broader
slight risk encompassing the Southern Appalachians, Lower Mississippi
Valley and Southeast. Training thunderstorms may cause exceptionally heavy
rain rates for the aforementioned areas. A moderate risk of severe
thunderstorms is in effect over parts of northeastern Louisiana, extreme
southeast Arkansas, central and northern Mississippi and northwest
Alabama. Strong tornadoes, very large hail and severe wind gusts are
forecast overnight. Regional outbreaks of severe thunderstorms and
tornadoes are forecast for parts of the Lower Mississippi Valley tonight.
Reduced visibility in the evening will add additional danger to those
traveling within the affected areas tonight.

Elsewhere, another low pressure system will bring heavy low elevation rain
and heavy mountain snow to the Pacific Northwest tonight through Wednesday
before shifting its attention to southern Oregon and northern/central
California on Thursday. Anywhere between 1-2 feet are likely for the
Cascades on Wednesday with isolated higher amounts possible. Parts of
northern Washington/Idaho and central/southern Idaho may receive between
4-8 inches through tomorrow. Snowfall will pickup over the southern
Cascades, northern California and the Sierra on Thursday with 1-2 feet of
snow possible for these areas. An additional 8-12 inches of snow are
possible for parts of the Northern Rockies on Thursday. Winter Storm
Watches Warnings and Winter Weather Advisories are in effect over much of
the Pacific Northwest and western mountain ranges.

Some light to moderate snowfall is forecast to impact portions of the
Upper Midwest/Great Lakes through tomorrow as moisture wraps around the
low pressure system and interacts with a cold continental airmass flowing
into the central third of the country. Winter Weather Advisories and
Winter Storm Warnings are in effect from southern Minnesota to the western
Upper Peninsula of Michigan. The departing cold front in the East will
shift winds out of the northwest leading to the development of lake effect
snow bands downwind of the Lower Great Lakes where 6-12 inches may fall on
Thursday. Temperatures will be above average across the East Coast through
Wednesday afternoon when the cold front will pass and drop temperatures.
The Great Plains begin to warm up beneath upper high pressure on Thursday.


Kebede


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