Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Wed Aug 02 2023

Valid 12Z Wed Aug 02 2023 - 12Z Fri Aug 04 2023

...There is a Moderate Risk of excessive rainfall over parts of the Middle
Mississippi Valley on Wednesday and a Slight Risk over parts of the
Ohio/Tennessee Valleys and Southern Appalachians, along with two areas
over the Northern/Central Plains on Thursday...

...There is a Slight Risk of severe thunderstorms over parts of the Middle
Mississippi Valley on Wednesday and the Central High Plains on Thursday...

...Excessive Heat Warnings and Advisories from parts of Central/Southern
Plains and the Lower Mississippi Valley/Central Gulf Coast...

A front extending from the Southeast across the Central Gulf Coast to the
Central Plains will be quasi-stationary through Thursday. East of the
boundary, showers and thunderstorms will develop over the Middle
Mississippi Valley, aided by tropical moisture and a stationary front
creating showers and thunderstorms with heavy rain over parts of Missouri
and Illinois. Therefore, the WPC has issued a Moderate Risk of excessive
rainfall over parts of the Middle Mississippi Valley through Thursday
morning. The associated heavy rain will create numerous areas of flash
flooding. Furthermore, many streams may flood, potentially affecting
larger rivers.

Additionally, the system will produce showers and severe thunderstorms
over parts of Missouri and Illinois. Therefore, the SPC has issued a
Slight Risk of severe thunderstorms over parts of the Middle Mississippi
Valley through Thursday morning. The hazards associated with these
thunderstorms are frequent lightning, severe thunderstorm wind gusts,
hail, and a few tornadoes.

Meanwhile, upper-level energy and a steady supply of moisture will produce
showers and thunderstorms with heavy rain over parts of Idaho, Utah,
Wyoming, and a small part of Colorado. Therefore, through Thursday
morning, the WPC has issued a Slight Risk of excessive rainfall over parts
of the Northern Intermountain Region, Great Basin, and Northern Rockies.
The associated heavy rain will create mainly localized areas of flash
flooding, with urban areas, roads, and small streams the most vulnerable.

Moreover, a weak front over the Northern Plains will move eastward into
the Upper Mississippi Valley/Upper Great Lakes. On Wednesday, the boundary
will produce showers and moderate to strong thunderstorms over parts of
the region.

On Thursday, upper-level energy and a weak front nearby will create
showers and severe thunderstorms over parts of extreme southeastern
Wyoming, western Nebraska, northwestern Kansas, and northeastern Colorado.
Therefore, the SPC has issued a Slight Risk of severe thunderstorms over
parts of the Central High Plains from Thursday through Friday morning. The
hazards associated with these thunderstorms are frequent lightning, severe
thunderstorm wind gusts, hail, and a minimal threat of tornadoes.

Additionally, showers and thunderstorms will produce heavy rain over parts
of the Northern High Plains and another area over the Central High Plains.
Therefore, the WPC has issued a Slight Risk of excessive rainfall over two
regions, parts of the Northern High Plains and the second area over the
Central High Plains, from Thursday through Friday morning. The associated
heavy rain will create mainly localized areas of flash flooding, with
urban areas, roads, and small streams the most vulnerable.

Further, the area of excessive rainfall over the Mississippi Valley moves
eastward and decreases slightly on Thursday. Therefore, the WPC has issued
a Slight Risk of excessive rainfall over parts of the Ohio/Tennessee
Valleys and the Southern Appalachians from Thursday through Friday
morning. The associated heavy rain will create mainly localized areas of
flash flooding, with urban areas, roads, and small streams the most
vulnerable. Also, showers and thunderstorms will move into parts of the
Northeast/Mid-Atlantic on Thursday. Elsewhere, a nearby front and ample
amounts of moisture will create showers and thunderstorms over parts of
the Southeast through Friday.

Furthermore, an upper-level high over the Central/Southern Plains will
create hot high temperatures. In addition, a few locations will have
record-high low temperatures contributing to areas not cooling off
overnight, which will also contribute to the effects of heat, prompting
Excessive Heat Warnings and Heat Advisories over portions of the
Central/Southern Plains and the Lower Mississippi Valley/Central Gulf
Coast.

In addition, the dangerous heat wave will continue this week across
portions of the Central and Southern Plains, the Lower Mississippi Valley,
and areas along the Gulf Coast. High temperatures will be well into the
90s and triple digits extending northward into the Central Plains. The
combination of heat and humidity will result in daily maximum heat indices
over 110 F expanding from eastern Texas across much of Louisiana and
southern Mississippi through midweek. These temperatures will persist
across the Lower Mississippi Valley through the weekend.

Additionally, expect several new record-warm nighttime lows along with
oppressive heat index values during the day. It is essential to have ways
to cool down and limit your heat exposure. These temperatures and heat
indices will pose a health risk to those without an effective cooling
method and/or adequate hydration. Be sure to follow heat safety
precautions.


Ziegenfelder


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