Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
256 PM EDT Tue Sep 16 2025

Valid 00Z Wed Sep 17 2025 - 00Z Fri Sep 19 2025

...Slow moving coastal low to bring heavy rain potential along the
Mid-Atlantic coast...

...Heavy rain and possible severe thunderstorms across the Plains Tuesday
and Wednesday...

...Tropical moisture from Mario begin to push into Southern California...

...Below average temperatures likely where wet weather occurs next two
days, otherwise above average temperatures expected across much of the
CONUS...

A well defined low pressure system sitting off the Mid-Atlantic coast
continue to bring showers, gusty winds, and chances for thunderstorms
along the eastern portion of North Carolina, Virginia, and southeastern
parts of Maryland. With rain rates expected to reach 1-2"/hr and chances
for occasional heavy downpours, there is a Slight Risk (level 2/4) for
Excessive Rainfall and an increase chance for flash flooding for
northeastern North Carolina and parts of Virgina. The system will continue
to slowly move northwestern, but will continue to weaken as the low moves
inland. 

An upper-level low will bring some unsettled weather across the Central
Plains, as the trough will continue to form across the central CONUS. With
the combination of sufficient instability, moisture, and lift, Storm
Predicition Center has placed a Slight Risk (level 2/5) for severe
thunderstorms across the Central Plains and Eastern Colorodo/Wyoming.
Along with heavy showers and thunderstorms, other hazards supported by
this system will be possible hail, strong wind gust, and risk for
low-probability tornados through Wednesday.

Tropical moisture associated with Mario, currently moving northwestward
off the west coast of the Baja, will begin to possibly impact Southern
California Tuesday night through Wednesday, before pushing farther north
into Central California mid to late week.  While Mario is forecast to
weaken as it moves northwestward, this tropical moisture may bring
scattered showers into far southern coastal California and the offshore
islands Wednesday, with these showers pushing farther north into much of
Southern California on Thursday. Overall, any rainfall amount across the
Southwest and central Rockies will be beneficial, as these areas have been
notably dry. Climate Prediction Center has highlighted that most of the
Western U.S. has been drier than normal over the past month.    

Temperatures across much of CONUS for the next few days will be above
normal, with the upper and middle Mississippi Valley seeing 10-15 degrees
above normal. The exception will over the Plains, where below normal
temperatures will develop due to the upper-level low building over the
Central Plains. 

Oudit/Kong

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