Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
301 PM EST Wed Nov 10 2021

Valid 00Z Thu Nov 11 2021 - 00Z Sat Nov 13 2021

...Persistent heavy rain and higher elevation snow continue with series of
Pacific storms impacting the Northwest...

...Storm system bringing rain, thunderstorms, and wintry precip to the
eastern half of the country...

A series of Pacific storm systems will impact the Northwest through the
forecast period. An atmospheric river will help encourage waves of high
moisture into the region leading to widespread heavy rain. A Marginal Risk
of Excessive Rainfall remains in place for northwestern Oregon through
Wednesday morning with rain rates as high as 0.75 inches possible. A
second surge of moisture will impact the area Thursday with a Slight Risk
of Excessive Rainfall issued for the Cascades of Washington west to the
coast and south into far northwestern Oregon. Rainfall totals of 2-4 +
inches are possible, especially where orographic enhancements along the
mountains will promote heavier rainfall. A Marginal Risk remains in place
for the same areas on Friday as the heavy rain chances continue, with
another 1-2 + inches forecast. In all cases, the greatest concern for
flooding will be along any burn scar areas. Snow chances should remain
isolated to higher mountain peaks with generally warmer air in place
leading to high snow levels. Some scattered rain and snow showers are also
likely for the Northern and Central Rockies through the period out ahead
of each system.

An active weather pattern is currently in place across the central U.S. As
an upper-level trough exists the Rockies and moves over the Plains, a
surface low pressure system over the Central Plains will strengthen and
continue to the northeast throughout the forecast period, bringing
widespread rain, thunderstorms, and wintry precip to most of the eastern
half of the country.  A cold front will move across the Midwest and
Southern Plains Thursday evening east to the Great Lakes, Ohio Valley, and
Southeast on Thursday and reaching the East Coast on Friday. Widespread
rain and thunderstorms are likely ahead of the cold front. Severe weather
is possible through this evening for portions of northeastern Kansas,
central/eastern Oklahoma, and northern Texas. The Storm Prediction Center
has issued a Slight Risk of severe weather with for the threat of large
hail, gusty winds, and an isolated tornado or two. Otherwise, any
thunderstorms are expected to not reach severe levels through the rest of
the period. As colder air is funneled southward on the back side of the
system, a wintry mix of rain and snow will overspread the Northern Plains
Thursday and Upper Midwest Friday. The chance of accumulating snow has
been increasing in more recent model guidance and totals of 2-4 inches,
locally higher, appear possible.

A shortwave rounding the the upper-level trough will help encourage a
second surge of colder, Canadian air southward through the Midwest and
Plains Thursday night into Friday. Many areas across the Northern Plains,
Mid- to Upper Missouri Valley, and Upper Midwest will see highs in the 30s
on Friday, while the Ohio Valley to Central Plains will be in the 40s and
50s. Meanwhile, temperatures will be warm and above normal ahead of the
front, with 70s for the Gulf Coast and 50s for New England warming to the
low 70s for the Southeast and southern Mid-Atlantic.

Generally tranquil and dry conditions are expected across the Southwest,
southern Great Basin, and California. Above normal high temperatures are
forecast with 60s for the Great Basin and 70s and 80s for the Southwest
and California, with low 90s possible for the desert portions of the
Southwest on Friday.

Putnam


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