007
FXUS01 KWBC 021925
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
325 PM EDT Tue Sep 02 2025

Valid 00Z Wed Sep 03 2025 - 00Z Fri Sep 05 2025

...There is a Slight Risk of excessive rainfall over parts of
southern California and southwestern Arizona on Tuesday and
Wednesday...

...There is a Slight Risk of severe thunderstorms over parts of
the Central Plains and Middle Mississippi Valley on Wednesday...

...There are Extreme Heat Warnings and Heat Advisories over the
interior Northwest...

A weak front extending from the Tennessee Valley southwestward to
the Southern Plains will dissipate by Wednesday.  Moisture pooling
along the front will aid in producing showers and thunderstorms
over parts of the Tennessee Valley through Wednesday afternoon.

Moreover, monsoonal moisture, diurnal heating, and upper-level
impulses will produce showers and thunderstorms over
Central/Southern California, the Southwest, and the Great Basin
through Thursday. Heavy rain is expected to develop over parts of
southern California and southwestern Arizona. Therefore, the WPC
has issued a Slight Risk (level 2/4) of excessive rainfall over
southern California and southwestern Arizona through Wednesday
morning.  The associated heavy rain will primarily create
localized areas of flash flooding, with urban areas, roads, small
streams, and low-lying areas being the most vulnerable.

In addition, showers and thunderstorms with heavy rain will
develop over southern California and southwestern Arizona on
Wednesday into Thursday. Therefore, the WPC has issued a Slight
Risk (level 2/4) of excessive rainfall over southern California
and southwestern Arizona from Wednesday through Thursday morning.
The associated heavy rain will primarily create localized areas of
flash flooding, with urban areas, roads, small streams, and
low-lying areas being the most vulnerable.

Meanwhile, a front extending from the Upper Mississippi Valley
across the Northern Rockies and into the Northern High Plains will
move south and eastward to the Lower Great Lakes/Central
Appalachians into the Ohio Valley by Thursday. The system will
produce showers and thunderstorms over the Upper Mississippi
Valley on Tuesday evening, moving across the Great Lakes on
Wednesday, and into the Lower Great Lakes/Northeast to the Central
Appalachians and Mid-Atlantic on Thursday.

Along the southern edge of the front, showers and severe
thunderstorms will develop over parts of the Central Plains/Middle
Mississippi Valley. Therefore, the SPC has issued a Slight Risk
(level 2/5) of severe thunderstorms over parts of the Central
Plains/Middle Mississippi Valley from Wednesday through Thursday
morning.  The hazards associated with these thunderstorms are
frequent lightning, severe thunderstorm wind gusts, hail, and a
minimal threat of tornadoes. Additionally, there is an increased
threat of hail, two inches or greater, over parts of the region.

A second front will move southward out of West-Central Canada
overnight Wednesday, moving into the Upper Mississippi Valley by
Thursday evening. The system will produce showers and
thunderstorms over parts of the Northern Plains by Thursday
morning and into the Upper/Middle Mississippi Valley by Thursday
evening. Furthermore, a third front will linger over Florida
through Thursday. Tropical moisture and the front will aid in
producing showers and thunderstorms over Florida, also through
Thursday.

Lastly, an upper-level ridge over the Northwest will allow
temperatures to rise into the nineties and the triple digits
through Thursday. The NWS has issued Extreme Heat Warnings and
Heat Advisories over the interior Northwest.


Ziegenfelder


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