Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
402 PM EDT Sun Aug 27 2023

Valid 00Z Mon Aug 28 2023 - 00Z Wed Aug 30 2023

...There is a Slight Risk of excessive rainfall over the Southeastern
portions of the U.S. through Tuesday...

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

...Tropical Storm IDALIA is forecast to strengthen while moving northward
across the Gulf of Mexico...

A front extending from parts of the Mid-Atlantic and then roughly
southwestward to the Gulf Coast States will be quasi-stationary through
Tuesday. Tropical moisture pooling along the boundary will produce showers
and thunderstorms with heavy rain over the southern Mid-Atlantic.
Therefore, the WPC has issued a Slight Risk of excessive rainfall over
parts of the southern Mid-Atlantic through Monday morning. The associated
heavy rain will create mainly localized areas of flash flooding, with
urban areas, roads, and small streams the most vulnerable.

A second area of showers and thunderstorms with heavy rain will develop
over parts of western Tennessee. Therefore, the WPC has issued a Slight
Risk of excessive rainfall over parts of the Tennessee Valley through
Monday morning. The associated heavy rain will create mainly localized
areas of flash flooding, with urban areas, roads, and small streams the
most vulnerable.

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.

Generally, on Sunday into Monday, an area of showers and strong to severe
thunderstorms will develop along the boundary from the southern
Mid-Atlantic/Southeast to the Gulf Coast States and Southern Plains.
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 Tuesday as showers and
thunderstorms with heavy rain develop over parts of the southern
Mid-Atlantic/Southern Appalachians. Therefore, on Tuesday, 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 Sunday evening
into Monday morning. Moreover, a front develops over the Pacific Northwest
on Tuesday producing scattered showers and thunderstorms.

Meanwhile, an upper-level high over the Central Rockies will slowly
retreat into Mexico as a front moves across the south-central portion of
the country 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 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 †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, Tropical Storm IDALIA, near the Yucatan Peninsula, is forecast to
strengthen while moving northward across the Gulf of Mexico. Check the
latest advisory from the National Hurricane Center for IDALIA s most
current track and strength. By Tuesday, IDALIA is forecast to be close
enough to stream tropical moisture northward into the Eastern Gulf Coast,
producing showers and thunderstorms with heavy rain. Therefore, on
Tuesday, the WPC has issued a Slight Risk of excessive rainfall with these
thunderstorms over parts of the Eastern Gulf Coast. The associated heavy
rain will create mainly localized areas of flash flooding, with urban
areas, roads, and small streams the most vulnerable.


Ziegenfelder


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