Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
347 AM EDT Thu Sep 30 2021

Valid 12Z Thu Sep 30 2021 - 12Z Sat Oct 02 2021

...Heavy rain and scattered flash flooding possible across the Southern
Plains over the next few days...

...Severe weather with large hail and locally damaging wind gusts are
possible across parts of West Texas today...

...Well above average temperatures continue across the Midwest and Upper
Great Lakes as cooler air surges into the central/southern Rockies...

The biggest weather story over the next few days across the Lower 48 will
be found throughout the central and south-central United States. An
advancing cold front that currently extends from the Northern Plains to
the Southern Rockies is expected to rush into the Southern Plains today
before stalling and lingering throughout the Great Plains into the early
part of the weekend. Ahead of the cold front, ample moisture flowing out
of the western Gulf of Mexico will allow for numerous rounds of robust
thunderstorms to develop across the central and southern Plains today and
Friday. The greatest chance for thunderstorms to turn severe will be
located across West Texas today, with damaging wind gusts and large hail
the primary concern. Otherwise, the more widespread hazard is likely to be
the threat of flash flooding. The slow-moving nature of the frontal
boundary combined with multiple clusters of thunderstorms could lead to
instances of very heavy rainfall throughout the Lone Star State. A Slight
Risk (level 2/4) of excessive rainfall has been issued for much of central
and West Texas today, shifting slightly east on Friday into
central/south-central Texas. Given the tropical airmass in pace, isolated
instances of flash flooding will also remain possible across the Lower
Mississippi Valley as well as the Central Plains over the next few days.

At the top of an anomalous upper-level ridge, the Midwest and Upper Great
Lakes will end the month of September with temperatures well above
average. Highs into the upper 70s and 80s are forecast, which is around 15
to 20 degrees above normal for this time of year. Slightly milder weather
is expected by Friday. On the other end of the spectrum, much cooler and
below average high temperatures will be found across the central/southern
Rockies, Intermountain West, and central High Plains behind a potent cold
front. In fact, Freeze Warnings are in effect this morning across eastern
portions of the Snake River Valley in Idaho, as well as parts of southwest
Nevada. Crisp, fall-like temperatures are also forecast across the
Northeast as an upper-level low pressure system gently swings across the
region. This will also aid in the development of a few showers across New
England this afternoon.

Snell


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