Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
310 PM EDT Thu Aug 25 2022

Valid 00Z Fri Aug 26 2022 - 00Z Sun Aug 28 2022

..There is a Slight Risk of excessive rainfall over parts of the Lower
Mississippi Valley/Central Gulf Coast/Western Gulf Coast and the Northern
Rockies/Northern High Plains through Friday morning...

...There is a Slight Risk of severe thunderstorms over parts of the
Northeast from Friday into Saturday morning...

...Low temperatures will be near or tie high minimum overnight
temperatures over parts of the Northwest...

Tropical moisture, upper-level energy, and a weak front over parts of the
Western and Central Gulf Coast into the Southeast will aid in producing
showers and thunderstorms with heavy rain over parts of Texas, Louisiana,
Mississippi, Alabama, the western tip of the Florida Panhandle. Therefore,
the WPC has issued a Slight Risk of excessive rainfall over parts of the
Lower Mississippi Valley/Central Gulf Coast and Western Gulf Coast 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.

The threat of excessive rainfall reduces on Friday over the
Western/Central Gulf Coast/Southeast. However, the system will continue to
produce showers and thunderstorms with possible heavy rain over the area.
Therefore, the WPC has issued a Marginal Risk of excessive rainfall over
parts of the Western/Central Gulf Coast and Southeast 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, an upper-level low over the Northwest will aid in producing
showers and thunderstorms with heavy rain over northern Idaho and
northwestern Montana, southeast Montana, northeast Wyoming, and South
Dakota through Friday. Therefore, the WPC has issued a Slight Risk of
excessive rainfall over parts of the Northern Rockies and Northern High
Plains 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. On Friday, the threat of excessive
rainfall ends; however, showers and thunderstorms will continue over parts
of the region.

Moreover, monsoonal moisture and upper-level energy will aid in producing
diurnal showers and thunderstorms over parts of the Southwest, Great
Basin, and Central/Southern Rockies. Therefore, the WPC has issued a
Marginal Risk of excessive rainfall over parts of the Southwest, Great
Basin, and Central/Southern Rockies through Saturday morning. The
associated heavy rain will create localized areas of flash flooding,
affecting areas that experience rapid runoff with heavy rain.

In the meantime, a wave of low pressure over the Great Lakes moves
eastward to the Northeast by Friday, and then the front pushes off the
Northeast Coast by Saturday. The system will produce showers and
thunderstorms from the Great Lakes/Ohio Valley overnight Thursday moving
into the Northeast on Friday. The low pressure will destabilize the
atmosphere over parts of the Northeast, producing showers and
thunderstorms that will become severe. Therefore, the SPC has issued a
Slight Risk of severe thunderstorms over parts of the Northeast from
Friday into Saturday morning. The hazards associated with these
thunderstorms are frequent lightning, severe thunderstorm wind gusts,
hail, and a few tornadoes.

In addition, weak upper-level ridging over the Pacific Northwest Coast
will keep temperatures warm over parts of the region through Friday. The
overnight low temperature will be near or tie high minimum overnight
temperatures over parts of the Northwest through Friday. Therefore,
record-breaking relatively high low temperatures will contribute to areas
not cooling off overnight, which will also contribute to the effects of
heat. The local forecast office has issued Heat Advisories over parts of
the Puget Sound area through midnight local time.

Ziegenfelder

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