Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
402 PM EDT Sun Sep 24 2023

Valid 00Z Mon Sep 25 2023 - 00Z Wed Sep 27 2023

...There are two areas of Slight Risk of excessive rainfall over parts of
the northern Mid-Atlantic/Southern New England and second over the
Southern Plain and Middle/Lower Mississippi Valley...

...There is a Slight Risk of severe thunderstorms over parts of the
Southern Plains...

...There are Heat Advisories over parts of the Southern Plains...

...Air Quality Alerts over parts of Central California...

Former Tropical Storm OPHELIA has become a non-tropical low over the
northern Mid-Atlantic that will slowly move eastward out over the Western
Atlantic by Monday. The low will continue to pull moist air off the
Atlantic, producing areas of heavy rain over parts of eastern
Pennsylvania, most of New Jersey, extreme southeastern New York State/Long
Island, and Connecticut. Therefore, the WPC has issued a Slight Risk of
excessive rainfall over parts of northern Mid-Atlantic and Southern New
England. The associated heavy rain will create mainly localized areas of
flash flooding, with urban areas, roads, and small streams the most
vulnerable.

Meanwhile, a front extending from the Northern Plains/Upper Mississippi
Valley into the Middle Mississippi Valley and then into the Southern
Plains will slowly dissipate by Monday evening. The system will produce
showers and thunderstorms from parts of the Upper Midwest into the
Southern Plains/Lower Mississippi Valley through Monday evening. The
system will also create showers and severe thunderstorms over parts of
eastern Texas. Therefore, the SPC has issued a Slight Risk of severe
thunderstorms over parts of the Southern Plains and a small section of the
Lower Mississippi Valley through Monday morning. The hazards associated
with these thunderstorms are frequent lightning, severe thunderstorm wind
gusts, hail, and a few tornadoes.

In addition, the front will also create an area of heavy rain over
southeastern Oklahoma, southwestern Arkansas, northwestern Louisiana, and
northeastern Texas. Therefore, through Monday morning, the WPC has issued
a Slight Risk of excessive rainfall with these thunderstorms over parts of
the Southern Plains/Lower Mississippi Valley. The associated heavy rain
will create mainly localized areas of flash flooding, with urban areas,
roads, and small streams the most vulnerable.

Furthermore, an upper-level low over the Upper Midwest will aid in
producing showers and thunderstorms with heavy rain over parts of
southeastern Minnesota and western Wisconsin on Monday. Therefore, the WPC
has issued a Slight Risk of excessive rainfall with these thunderstorms
over parts of the Upper Mississippi Valley from Monday into Tuesday
morning. The associated heavy rain will create mainly localized areas of
flash flooding, with urban areas, roads, and small streams the most
vulnerable.

On Monday, the threat of severe thunderstorms and excessive rainfall
decreases slightly to a Marginal Risk over the Southern Plains and Lower
Mississippi Valley. On Tuesday, showers and thunderstorms will continue
over parts of the Central Gulf Coast and the Southeast.

Moreover, weak upper-level ridging over Texas and high temperatures in the
upper 90s near 100 and dew points in the mid-70s have prompted Heat
Advisories over eastern Texas. Next, smoke from wildfires in California
will reduce air quality over parts of Central California, prompting Air
Quality Warnings over the area.

Lastly, a front moving onshore over the Pacific Northwest on Sunday night
will move inland to the Northern High Plains by Tuesday. The system will
have a plume of moisture associated with it, creating rain over parts of
the Pacific Northwest and Northern California from Sunday night into
Monday. Behind the front, a component of onshore flow will aid in
continuing the rain over the area through Tuesday evening.


Ziegenfelder


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