Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
425 PM EDT Thu Sep 23 2021

Valid 00Z Fri Sep 24 2021 - 00Z Sun Sep 26 2021

...There is a Slight Risk of excessive rainfall over parts of the
Northeast/northern Mid-Atlantic through Friday morning...

...Temperatures will be 10 to 20 degrees above average over parts of New
England through Saturday...

A cold front extending from Lake Ontario to along the Mid-Atlantic Coast
will move slowly into New England through Friday before stalling over
Maine Friday night. The same cold front is also over central Florida and
will slowly move down the peninsula through this weekend. A narrow ribbon
of Atlantic moisture streaming ahead of the boundary will spread into New
England tonight and then linger over eastern Mass and much of Maine Friday
night through Saturday. Showers and thunderstorms, with embedded heavy
rain, will continue develop along ahead of the front through Saturday. WPC
has issued a Slight Risk of excessive rainfall with these thunderstorms
over parts of the Northeast/northern Mid-Atlantic through Friday morning.
The associated heavy rain will create mainly localized areas of flash
flooding, with urban areas, roads, and small streams the most vulnerable.
The excessive rainfall threat is Marginal for portions of New England on
Friday and Saturday.

Upper-level ridging and warm moist air flowing into the Northeast ahead of
the cold front will allow temperatures to be 10 to 20 degrees above
average over parts of the New England through Saturday when the front
should reach Down East Maine. In addition, the trailing front drifting
down the Florida Peninsula through Saturday will aid in the further
development of showers and thunderstorms.

Meanwhile, another front over the Upper Midwest to the Great Basin will
move into the Great Lakes overnight Friday and into the Lower Great Lakes
by Saturday. On Friday, showers and thunderstorms will develop along and
ahead of the boundary over parts of the Upper Mississippi Valley/Upper
Great Lakes, moving into the Great Lakes/Ohio Valley on Saturday.

Elsewhere, upper-level energy and moisture over the Southwest will aid in
producing widely scattered showers and thunderstorms over the area through
Saturday. Additionally, upper-level ridging just off the West Coast and
weak high pressure at the surface will create light wind over the San
Joaquin Valley provide stagnant airflow. Therefore, Air Quality Alerts are
over parts of California due to smoke from wildfires.

Ziegenfelder

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