Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
411 PM EDT Sat Aug 26 2023

Valid 00Z Sun Aug 27 2023 - 00Z Tue Aug 29 2023

...There is a Slight of excessive rainfall migrating from over parts of
the Middle Mississippi Valley on Saturday to the Mid-Atlantic on
Sunday/Monday...

...There is a Slight Risk of severe thunderstorms over parts of the
Middle/Lower Mississippi Valley...

...Excessive Heat Warnings and Advisories from parts of the Southern
Plains, the Middle/Lower Mississippi Valley, and the Southeast...

A front extending from parts of the Northeast along the coast to the
Mid-Atlantic and then roughly westward to the Southern Plains will move
off the Northeast/Mid-Atlantic Coast and slowly settle southward over the
Gulf Coast States by Monday. Tropical moisture pooling along and north of
the boundary will produce showers and thunderstorms with heavy rain over
the Middle Mississippi Valley. Therefore, the WPC has issued a Slight Risk
of excessive rainfall over parts of the Middle Mississippi/Tennessee
Valleys through Sunday morning. The associated heavy rain will create
mainly localized areas of flash flooding, with urban areas, roads, small
streams, and burn scars the most vulnerable. Showers and thunderstorms
will develop along and ahead of the boundary from the Southern Plains to
the Mid-Atlantic.

Showers and severe thunderstorms will develop over parts of the
Middle/Lower Mississippi Valley. Therefore, the SPC has issued a Slight
Risk of severe thunderstorms over parts of the Middle/Lower Mississippi
Valley through Sunday morning. The hazards associated with these
thunderstorms are frequent lightning, severe thunderstorm wind gusts, and
minimal threat of hail and tornadoes.

On Sunday, as the front moves southward, showers and thunderstorms with
heavy rain will develop over parts of the southern Mid-Atlantic.
Therefore, the WPC has issued a Slight Risk of excessive rainfall over
parts of the southern Mid-Atlantic from Sunday into Monday morning. The
associated heavy rain will create mainly localized areas of flash
flooding, with urban areas, roads, and small streams the most vulnerable.

In addition, on Sunday, the threat of severe thunderstorms has decreased
slightly. Showers and strong to severe thunderstorms will develop along
the front over parts of the Southeast, Tennessee Valley, and southern
Mid-Atlantic. Therefore, the SPC has issued a Marginal Risk of severe
thunderstorms over parts of the Southeast, Tennessee Valley, and southern
Mid-Atlantic from Sunday into Monday morning. The hazards associated with
these thunderstorms are frequent lightning, severe thunderstorm wind
gusts, minor threat of hail, and a minimal threat of tornadoes.
Furthermore, upper-level energy will aid in producing showers and
thunderstorms over parts of the Rockies into the Southern High Plains on
Sunday.

The threat of excessive rainfall continues on Monday as showers and
thunderstorms with heavy rain develop over parts of the southern
Mid-Atlantic/Southern Appalachians. Therefore, on Monday, the WPC has
issued a Slight Risk of excessive rainfall with these thunderstorms over
parts of the southern Mid-Atlantic/Southern Appalachians. The associated
heavy rain will create mainly localized areas of flash flooding, with
urban areas, roads, and small streams the most vulnerable.

Elsewhere, wildfire smoke over parts of the Pacific Northwest has prompted
Air Quality Alerts over parts of the Pacific Northwest on Saturday evening
into Sunday morning.

Meanwhile, an upper-level high over the Central Rockies will slowly
retreat into Mexico by Monday. The high will create oppressive daytime
heat and limited overnight cooling, which will also contribute to the
effects of heat, prompting Excessive Heat Warnings and Heat Advisories
over portions of the Southern Plains, the Lower Mississippi Valley, and
parts of the Southeast.

In addition, the dangerous heat wave will persist for portions of the
southern U.S. through Monday. Record high temperatures combined with
unusually high humidity levels will lead to heat indices near record
levels over the Middle Mississippi Valley and across the Gulf Coast region.

Extreme heat and a lack of overnight cooling will unfortunately persist
over much of the South ahead of a cold front, especially along the Gulf
Coast from Texas to Florida through Monday. The heat of this intensity
poses a health risk to everyone with effective cooling and/or adequate
hydration. Do not underestimate the potential for heat-related illness â€
have a way to break your heat exposure, cool down, and stay hydrated!
Following a brief reprieve, dangerous heat is likely to return to much of
the Southern Plains and Lower Mississippi Valley during the first week of
September.

Lastly, a Tropical disturbance is forecast to develop over the Gulf of
Mexico near the Yucatan Peninsula that may move northward over the Gulf of
Mexico during the week.


Ziegenfelder


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