FXUS01 KWBC 242000
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
359 PM EDT Fri Sep 24 2021

Valid 00Z Sat Sep 25 2021 - 00Z Mon Sep 27 2021

...There is a Marginal Risk of excessive rainfall over parts of
Southern California and the Southwest through Sunday morning...

...Temperatures will be 10 to 20 degrees above average over parts
of the Northern/Central High Plains and Northern Rockies...

A front extending from the parts of the Northeast to Florida will
remain quasi-stationary until Sunday when upper-level energy aid
invigorates the boundary while moving eastward off the Northeast
Coast. The moisture connection off the Atlantic will weaken
overnight Friday.

Showers and thunderstorms will develop along and ahead of the
front through Sunday morning.  There is an isolated threat of
excessive rainfall with these storms through Sunday.

Meanwhile, another front over the Upper Great Lakes roughly
southwestward to the Southern High Plains will move eastward to
the Northeast on Sunday. Showers and thunderstorms will develop
along and ahead of the boundary over parts of the Upper Great
Lakes, moving into the Lower Great Lakes/Ohio Valley on Saturday
and into parts of the Northeast on Sunday.

Furthermore, upper-level energy and moisture over Southern
California and the Southwest will aid in producing widely
scattered showers and thunderstorms over the area through Sunday.
Some of the thunderstorms will produce heavy rain, but this will
be isolated.  Therefore, the WPC has issued a Marginal Risk of
excessive rainfall over parts of Southern California and the
Southwest through Sunday morning.  The associated heavy rain will
create localized areas of flash flooding, affecting areas that
experience rapid runoff with heavy rain. However, the excessive
rainfall threat is minimal yet will continue over the region
through Sunday.

Additionally, upper-level ridging will move into parts of the
Northern Rockies. At the same time, weak high pressure at the
surface over California will create light wind over the San
Joaquin Valley provide stagnant airflow. Therefore, Air Quality
alerts are over parts of California due to wildfire smoke. In the
meantime, temperatures will be 10 to 20 degrees above average over
parts of the Northern/Central High Plains and Northern Rockies.
The temperatures and the gusty winds with decreasing humidity will
aid in producing an area of Elevated Risk for fire weather through
Saturday morning. Therefore, Red Flag Warnings are up over parts
of the Northern Plains.

Ziegenfelder

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


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