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