Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
356 AM EDT Thu Jun 29 2023

Valid 12Z Thu Jun 29 2023 - 12Z Sat Jul 01 2023

...There is a Slight Risk of excessive rainfall over parts of the Ohio
Valley and Central High Plains...

...There is an Enhanced Risk of severe thunderstorms over parts of the
Middle Mississippi and Ohio Valleys on Thursday; a Slight Risk of severe
thunderstorms over parts of the Middle Mississippi/Ohio Valleys on
Thursday...

...Excessive Heat Warnings and Advisories over parts of the Southern
Rockies, Southern High Plains, Central/Southern Plains, Middle/Lower
Mississippi Valley, Central Gulf Coast...

...Air Quality alerts over parts of the Upper/Middle Mississippi Valley,
Great Lakes, Western Ohio Valley, Central Appalachians, Northeast, and
Mid-Atlantic...

A front extending from the Tennessee Valley to the Middle Mississippi
Valley, then westward to the Central High Plains, moves into the Great
Lakes to the Middle Mississippi Valley, then southwestward to the Southern
High Plains by Saturday. Moisture streaming northward over the Mississippi
Valley into the boundary and upper-level energy will create showers and
severe thunderstorms over parts of the Middle Mississippi/Ohio Valleys
westward into the Central High Plains. Therefore, the SPC has issued an
Enhanced Risk of severe thunderstorms over parts of the Middle Mississippi
and Ohio Valleys through Friday morning. The hazards associated with these
thunderstorms are frequent lightning, severe thunderstorm wind gusts,
hail, and a few tornadoes. Additionally, on Thursday, there is a threat of
two-inch or greater hail over parts of the Middle Mississippi and Ohio
Valleys and Central High Plains.

Moreover, the showers and thunderstorms will produce heavy rain over parts
of the Ohio Valley and Central High Plains. Therefore, the WPC has issued
a Slight Risk of excessive rainfall over two areas, parts of the Ohio
Valley and Central High Plains. The associated heavy rain will create
mainly localized areas of flash flooding, with urban areas, roads, and
small streams the most vulnerable.

Further, the front moves into the Great Lakes and Ohio Valley on Friday,
producing showers and severe thunderstorms over parts of the
Ohio/Tennessee Valleys, Middle Mississippi Valley, and Central
Appalachians. Therefore, the SPC has issued a Slight Risk of severe
thunderstorms over parts of the Ohio/Tennessee Valleys, Middle Mississippi
Valley, and Central Appalachians from Friday into Saturday morning. The
hazards associated with these thunderstorms are frequent lightning, severe
thunderstorm wind gusts, hail, and a few tornadoes.

The threat of excessive rainfall decreases slightly on Friday. Therefore,
the WPC has issued a Marginal Risk of excessive rainfall over a wavy band
from parts of the Northeast, Central Appalachians, Ohio Valley, Middle
Mississippi Valley, Central Plains, and Central High Plains from Friday
into Saturday morning. The associated heavy rain will create localized
areas of flash flooding, affecting areas that experience rapid runoff with
heavy rain.

Meanwhile, upper-level impulses and an upper-level trough will trigger
scattered showers and embedded thunderstorms over parts of the North East
on Thursday through Friday evening. In addition, moisture and upper-level
impulses will create showers and thunderstorms over parts of Florida
through Saturday.

Moreover, upper-level energy moving eastward from California/Great Basin
to Central Rockies/Central Plains will produce showers and thunderstorms
over parts of the Northern/Central Rockies and into parts of the Southern
Rockies from Thursday evening into Saturday.

Furthermore, upper-level ridging over the south-central portion of the
country will expand northward into the Middle Mississippi Valley bringing
with the ridge hot high temperatures and temperatures not cooling off much
overnight, which have contributed to Excessive Heat Warnings and Heat
Advisories over the eastern third of Texas and the southwestern corner,
southern New Mexico, eastern Oklahoma, eastern Kansas, Missouri, Arkansas,
Louisiana, southern Illinois, Western Tennessee, Mississippi, and Alabama.

Lastly, wildfire smoke from Canada will reduce air quality over parts of
the Upper/Middle Mississippi Valley, Great Lakes, Western Ohio Valley,
Central Appalachians, Northeast, and Mid-Atlantic, prompting Air Quality
Warnings over the area. 


Ziegenfelder


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