Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
409 AM EDT Sat Aug 05 2023

Valid 12Z Sat Aug 05 2023 - 12Z Mon Aug 07 2023

...Dangerous heat will continue for the Desert Southwest, Southern Plains
and Lower Mississippi Valley but relief for some is coming beginning on
Sunday...

...Potential for severe thunderstorms and/or flash flooding from the
central/northern Plains into parts of the Midwest...

Excessive Heat Warnings are in effect across a large portion of Texas and
Oklahoma into the Lower Mississippi Valley as well as southeastern
California into southern Arizona for today. This is due to the influence
of a large and elongated upper level ridge extending from Arizona/New
Mexico to the central Gulf Coast. High temperatures across the Southern
Plains will again be in the low to mid-100s today, with peak heat index
values of 110 to 115 given high humidity in place. Similar heat is
expected across portions of the Desert Southwest, although lower dewpoints
across California and Arizona will support more of a dry heat across the
region with actual air temperatures climbing to 105 and locally over 110
for a few locations.

Locations north of the southern U.S. heat wave will see the potential for
strong to severe thunderstorms, with a focus for wind and hail from
southeastern Colorado into southern Kansas and northern Oklahoma
today/tonight. One of the contributors to the active weather will be a
strong upper level disturbance forecast to move eastward through the
central and northern Plains over the next 24 hours. This system will be
associated with a slow moving area of low pressure at the surface over
South Dakota and anomalous moisture supporting a threat for heavy rain and
possible flash flooding from South Dakota into western portions of Iowa
and Minnesota. A dual threat for severe thunderstorms and flash flooding
will exist across portions of Illinois and Indiana today near an eastward
moving surface cyclone. Farther south near a lingering frontal boundary
across northern Oklahoma will be the potential for strong to severe
thunderstorms with threats of strong winds and large hail the main
concerns.

The central U.S. storm system will shift east on Sunday, translating the
threats for severe thunderstorms and flash flooding into portions of the
Midwest and Upper Mississippi Valley. A relatively strong cold front will
trail the accompanying low pressure center and sweep into Oklahoma and
Arkansas by Monday morning, lowering high temperatures to near or below 90
degrees for many across Oklahoma, Kansas into Missouri and Arkansas. The
cold front will bring an end to the oppressive heat for these northern
locations during the day on Monday but heat and humidity will remain south
of the cold front into much of central/eastern Texas, Louisiana and
southern Mississippi, as well as the Desert Southwest.

Otto


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