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

Valid 12Z Sat Sep 09 2023 - 12Z Mon Sep 11 2023

...Dangerous heat will build across the Southwest, while continuing across
parts of Texas...

...Widespread showers and storms and cooler temperatures will spread
across the northern to the central Plains and the upper to mid Mississippi
Valley...

...Unsettled weather will continue across the East, with locally heavy
rainfall possible...

It will be another day of above-normal to record-breaking heat across
portions of Texas and the southwestern U.S.  Heat advisories remain in
effect today for portions of central and southeastern Texas, where heat
indices are expected to climb well above 100F once again.  The dome of
high pressure responsible for the recent heat across the southern Plains
will shift slightly west, raising temperatures across the Southwest this
weekend.  An Excessive Heat Warning is in effect today through late Sunday
for portions of the southern California and southwestern Arizona lower
deserts, including the Phoenix metro.  Daytime highs in this area are
forecast to climb to around 110F, with overnight lows only dropping into
the 80s both days.

Contrasting the heat in the Southwest, below-normal temperatures will
begin to spread southeast behind a well-defined cold front dropping south
from the northern into the central Plains and the upper into the mid
Mississippi Valley.  Showers and thunderstorms will accompany this system,
with isolated strong to severe storms possible from the northern High
Plains into the central Plains today.  As the system drops farther south
on Sunday, increasing moisture along and ahead of the front will raise the
threat for heavy rainfall amounts and potential flooding across portions
of the central Plains.

In the East, a stalled frontal boundary will continue to focus periods of
showers and thunderstorms through the weekend.  Isolated strong to severe
storms are possible, as well as heavy rain and localized flash flooding.

Pereira

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