Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
357 AM EDT Sun Oct 24 2021

Valid 12Z Sun Oct 24 2021 - 12Z Tue Oct 26 2021

...There is a High Risk of excessive rainfall for the Sierra Nevada
Mountains and a Slight Risk of excessive rainfall for the Middle
Mississippi/Ohio Valleys through Monday morning...

...Heavy snow for the Sierra Nevada Mountains...

...There is an Enhanced Risk of Severe Thunderstorms today across portions
of the Middle/Lower Mississippi Valley; a Slight Risk is in effect for
parts of the Mid-Atlantic and Southeast on Monday...

A powerful mid-latitude cyclone will arrive over the Pacific Northwest
this morning. This system will generate enough precipitation across the
region to be classified as an Atmospheric River event. A storm warning is
in effect for the Pacific Northwest coast, while Flash Flood watches and
high wind warnings have been issued for areas farther inland. Heavy
rainfall is expected for much of the northern/central California as well
as the Pacific Northwest coast, with these areas slated to accumulate 3-6
inches of rain, with isolated higher amounts, over the next two days. A
High Risk of Excessive Rainfall leading to Flash Flooding is in effect for
parts of northern California and including the Sierra. Heavy snow will
also occur, with much of the Sierra Nevada likely to receive in-excess of
2 feet over the next couple of days. Temperatures will drop significantly
in the wake of this system. High temperatures in California will be
between 20-25 degrees below average on Monday, as surface ridging builds
across the state. The Pacific system will go on to produce moderate
rainfall and heavy mountain snow as it moves into the Rockies on Monday.

Meanwhile, another low pressure system is forecasted to develop over the
Plains today. This system is expected to produce heavy rainfall and
thunderstorms for much of the Mississippi Valley and Midwest over the next
couple of days. Rainfall totals on the magnitude of 2-3 inches are
expected with locally higher amounts possible. A Slight Risk of Excessive
Rainfall leading to Flash Flooding is in effect across the Middle
Mississippi Valley and Midwest today as a result. Thunderstorm activity is
expected to take place within the general focus areas of this system over
the next two days. The Storm Prediction Center issued an enhanced risk of
severe thunderstorms for much of the Middle Mississippi Valley today. The
severe and flash flooding threats shift into the Mid-Atlantic and
Northeast on Monday, where a Slight Risk of Severe Thunderstorms was
issued by the Storm Prediction Center. An enhanced fire weather risk
continues for parts of the Southern Plains over the next couple of days,
due to warm temperatures and dry conditions.

Kebede

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