Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
338 PM EDT Sat Sep 09 2023

Valid 00Z Sun Sep 10 2023 - 00Z Tue Sep 12 2023

...Dangerous heat to continue across the Southwest and parts of Texas...

...Widespread showers, thunderstorms, and cooler temperatures will spread
across the northern/central Plains and Midwest...

...Unsettled weather continues across the East, with locally heavy
rainfall and isolated severe storms possible...

Summer maintains its grip over the Southwest, southern Plains, and western
Gulf Coast well into September. High temperatures into the triple digits
(up to the 110s in the Desert Southwest) through the end of this weekend
will threaten numerous daily high temperature records. When combined with
oppressive humidity in place, heat indices over 110 degrees are forecast
over parts of South Texas. Fortunately, a sinking cold front and weakening
upper ridge will bring relief to these regions by the beginning of the
week. Residents and visitors should continue to follow proper heat safety,
along with checking in on vulnerable friends, family, and neighbors.
Excessive Heat Warnings remain in effect over Desert Regions of southeast
California and southern Arizona.

A potent cold front ushering in below average temperatures across much of
the central U.S. by Monday will also produce widespread rainfall chances
over the next couple of days. Heavy rain and scattered severe
thunderstorms are possible in parts of the central Plains today and the
southern High Plains on Sunday as the aforementioned front pushes
southward. Heavy rain may also lead to areas of flash flooding throughout
western Kansas and nearby surrounding areas, prompting a Slight Risk
(level 2/4) of Excessive Rainfall to be issued. As an associated low
pressure system tracks into the Great Lakes on Monday, widespread showers
and isolated thunderstorms are forecast to shift eastward.

Throughout the Eastern U.S., a stationary boundary lingering over the
region along with elevated atmospheric moisture content and instability
will continue to fuel developing thunderstorms on Sunday, with these
rainfall chances mostly confining to the Northeast on Monday. Some storms
may turn severe and contain damaging wind gusts and from the Carolina to
New England, with the greatest threat centered over eastern Pennsylvania
through tonight. Additionally, the slow-moving nature of these storms and
intense downpours could lead to areas of flash flooding from the central
Appalachians to southern New England. Urban areas and valleys surrounded
by complex terrain are most at risk to rapid runoff and flooding impacts
until the end of the weekend.

Snell

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