Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
336 PM EDT Sat Sep 25 2021

Valid 00Z Sun Sep 26 2021 - 00Z Tue Sep 28 2021

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

...Temperatures will be 10 to 20 degrees above average over parts of the
Northern/Central Plains, Great Basin, 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 axis
associated with the front will also move eastward over the Atlantic Sunday
evening. 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. Therefore, the WPC has issued a
Marginal Risk of excessive rainfall over parts of the Northeast through
Sunday morning.  The associated heavy rain will create localized areas of
flash flooding, affecting areas that experience rapid runoff with heavy
rain.

Meanwhile, upper-level low and moisture over the Southwest will aid in
producing widely scattered showers and thunderstorms over the area through
Monday. 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 the Southwest through Monday 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 Monday.

Furthermore, another front over the Lower Great Lakes roughly
southwestward to the Southern High Plains will move eastward to the
Northeast on Sunday and dissipate. Showers will develop along and ahead of
the boundary over parts of the Lower Great Lakes into the Central
Appalachians/Ohio Valley through Saturday evening.  The rain will move
into the Northeast on Sunday and weaken.

Additionally, upper-level ridging over the Northern Rockies and 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 through Monday. In the
meantime, temperatures will be 10 to 20 degrees above average over parts
of the Northern/Central Plains, Great Basin, and Northern Rockies.


Ziegenfelder


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