Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
403 AM EDT Sat Jul 29 2023

Valid 12Z Sat Jul 29 2023 - 12Z Mon Jul 31 2023

...There is a Slight Risk of excessive rainfall over parts of the
Northeast and Ohio Valley/Central Appalachians...

...There is a Slight Risk of severe thunderstorms over parts of Southern
New England to the Mid-Atlantic/Central Appalachians and a second area
over parts of the Northern/Central High...

...Excessive Heat Warnings and Advisories from parts of Central/Southern
Plains eastward to the Middle/Lower Mississippi Valley and the western
Ohio/Tennessee Valleys and a second area from Southern New England to the
Mid-Atlantic and smaller areas over portions of California and Southwest...

A front extending from parts of the Northeast/Lower Great Lakes across the
Ohio Valley into the Middle Mississippi Valley, then northwestward across
the Central High Plains, will slowly move off the Mid-Atlantic/Northeast
Coast and southward to the Southeast to the Central Plains by Monday. The
system will produce showers and severe thunderstorms from parts of the
Northeast to the Mid-Atlantic. Therefore, the SPC has issued a Slight Risk
of severe thunderstorms over parts of Southern New England to the
Mid-Atlantic/Central Appalachians through Sunday morning. The hazards
associated with these thunderstorms are frequent lightning, severe
thunderstorm wind gusts, hail, and a few tornadoes.

Further, the showers and thunderstorms will also produce heavy rain over
parts of the Northeast and a second area over parts of the Central
Appalachians/Eastern Ohio Valley. Therefore, the WPC has issued a Slight
Risk of excessive rainfall over parts of the Northeast and the Central
Appalachians/Eastern Ohio Valley through Sunday morning. The associated
heavy rain will create mainly localized areas of flash flooding, with
urban areas, roads, and small streams the most vulnerable.

Moreover, a second area of showers and severe thunderstorms will develop
over the western portion of the front over southeastern Wyoming, eastern
Colorado, and far western Nebraska. Therefore, the SPC has issued a Slight
Risk of severe thunderstorms over parts of the Northern/Central High
Plains from Saturday through Sunday morning. The hazards associated with
these thunderstorms are frequent lightning, severe thunderstorm wind
gusts, hail, and a minimal threat of tornadoes.

On Sunday, the threat of excessive rainfall ends over the eastern half of
the country and the threat of severe thunderstorms is reduced slightly
over the East Coast. However, showers and thunderstorms with moderate to
heavy rain will develop over parts of the Southwest, Great Basin, and
Central/Southern Rockies and a second area over parts of the Northern High
Plains. The associated heavy rain will create localized areas of flash
flooding, affecting areas that experience rapid runoff with heavy rain.

Furthermore, along the western and central portions of the boundary
showers and moderate to severe thunderstorms will develop over parts of
the Northern/Central High Plains and a second area over parts of the
Middle/Lower Mississippi Valley and the Tennessee Valley on Sunday.

Upper-level energy and tropical moisture will also produce showers and
thunderstorms over parts of the Southeast through Sunday.

Meanwhile, an upper-level high over the Southwest to the Southern
Plains/Lower Mississippi Valley will bring hot high temperatures and hot
low temperatures that will contribute to areas not cooling off overnight,
which have contributed to Excessive Heat Warnings and Heat Advisories over
portions of the Central/Southern Plains eastward to the Middle/Lower
Mississippi Valley and the western Ohio/Tennessee Valleys. In addition,
moisture moving into the Southwestern portion of the country has reduced
the areal coverage of the Excessive Heat Warnings and Heat Advisories to
the southernmost counties of California. A second area of Excessive Heat
Warnings and Heat Advisories is over portions of Southern New England to
the Mid-Atlantic. The heat wave will also build early next week across the
south-central and southeastern U.S.


Ziegenfelder


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