799 
FXUS01 KWBC 031958
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
357 PM EDT Mon Aug 03 2026

Valid 00Z Tue Aug 04 2026 - 00Z Thu Aug 06 2026

...Frontal system to bring strong thunderstorms over the Upper
Mississippi Valley today before moving east...

...Lingering showers and thunderstorms expected in the Northeast
and Southeast today...

...A cold front will bring showers and thunderstorms with heavy
rainfall to the Great Lakes and Mississippi Valley by midweek...

An expansive cold front located across the Upper Mississippi
Valley will bring thunderstorms this afternoon and evening before
slowly moving eastward. The system will be supported by a
mid-level shortwave trough, where a moderately unstable
environment will support the potential for strong to severe
thunderstorms this evening. Storms will carry a risk of damaging
wind gusts and large hail, along with an isolated tornado risk.
The Storm Prediction Center (SPC) has outlined a Slight Risk
(level 2/5) of severe weather for parts of Minnesota and the far
eastern edges of the Dakotas. Thunderstorms are also likely in the
Southwest today, particularly across southern Arizona, where
hazards will primarily consist of damaging winds and isolated
hail. The SPC has also outlined a Slight Risk (level 2/5) of
severe weather in Arizona through the remainder of today. Rainfall
in the Southwest is expected to persist through midweek, where
heavy rainfall rates could produce scattered flash flooding; as
such, a Slight Risk (level 2/4) of excessive rainfall is in effect
for southern Arizona today and Tuesday.

The aforementioned cold front will lethargically progress eastward
across the central U.S., slowed considerably by the presence of a
building ridge farther east. A renewed round of benign
thunderstorms is forecast over the Upper Mississippi Valley on
Tuesday, before advancing into the Mid-Mississippi Valley and
Upper Great Lakes on Wednesday. Thunderstorms on Wednesday will
bring the potential for flash flooding given the slow movement of
the boundary and ample low-level moisture convergence in the
region. Consequently, there is a Slight Risk (level 2/4) of
excessive rainfall for the Mid-Mississippi Valley and Upper Great
Lakes on Wednesday.

Farther east, a stagnant frontal system will remain in place along
the East Coast over the next few days, maintaining showers and
thunderstorms across the Northeast today and the Southeast through
midweek. The building upper-level ridge will cause the boundary to
come to a halt, while a weak low-pressure circulation in the
Southeast taps into Gulf Stream moisture. This will support a
multi-day period of rainfall across the Southeast. However, given
the ill-defined structure of the front and the core moisture axis
remaining mostly offshore, precipitation will be more inconvenient
than hazardous for much of the period, with the boundary gradually
dissipating by midweek.

In the Southwest, heat will remain firmly entrenched across the
Desert Southwest through midweek. Daily record highs remain
possible, maintaining a Major to Extreme HeatRisk. Temperatures
are expected to remain in the 105 to 110-degree range for much of
the region, particularly today. Meanwhile, heat across the
Northern Rockies will finally begin to ease. Particularly in the
Southwest, residents are encouraged to limit outdoor activity,
stay hydrated, and check on vulnerable family, friends, and
neighbors.


Blanco-Alcala


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




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