Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Fri Sep 04 2026

Valid 12Z Fri Sep 04 2026 - 12Z Sun Sep 06 2026

...Rounds of strong to severe thunderstorms with locally heavy rain across
the lower Great Lakes to the Mid-Atlantic will slowly shift southward
during the Labor Day weekend...

...Monsoonal moisture could trigger scattered flash flooding in parts of
Arizona/New Mexico for the next few days...

...Heat persists across the midsection of the country as cooler air
expands further into the West Coast and the Northeast...

An upper-level trough deepening over southeastern Canada will sustain a
corridor of strong to severe thunderstorms stretching from the upper
Midwest to the Mid-Atlantic through the next couple of days. The cool air
mass associated with the trough is forecast to advance gradually into the
northeastern U.S. against the heat dome anchored over the midsection of
the country through the Labor Day weekend. This will shift the best chance
of severe weather and heavy rain southward from the lower Great Lakes to
the Mid-Atlantic today, mainly across the southern Mid-Atlantic on
Saturday. By Sunday morning, temperatures will dip into the 40s and 50s
across much of the interior Northeast.

Across the South, ample moisture stretching across the Gulf Coast region
to Florida, where weak disturbances travel along a trough of low pressure,
will trigger scattered thunderstorms that could cause instances of flash
flooding into the Labor Day weekend.

Meanwhile, monsoonal moisture will be prevalent across mainly Arizona and
New Mexico where showers and thunderstorms will be most active during the
late-day hours with locally heavy rain over the next several days. WPC
maintains a Slight Risk (level 2/4) of excessive rainfall straddling the
Arizona-New Mexico border for today. Urban areas and also dry washes and
burn scars will be most vulnerable to flooding. Farther north, a
relatively deep upper-level low for this time of year will continue to
push cool and unsettled weather through the Northwest, where widespread
showers and embedded thunderstorms have a nonzero chance of causing
localized flooding issues by Saturday and into early Sunday.

Temperatures continue to be well above average for September across most
areas east of the Rockies into the Labor Day weekend as an upper-level
ridge remains anchored over the midsection of the country. Heat Advisories
are widespread from the south-central Plains into the Mid-Atlantic, with
Extreme Heat Warnings centered in the Mid-Mississippi Valley, for
temperatures and heat indices well into the 90s and 100s. Warm low
temperatures will cause added heat stress to vulnerable people and
infrastructure, while also setting widespread records for warm minimums.
Major to Extreme HeatRisk is widespread. See WPC's Key Messages for more
information on the heat. The Northeast to Mid-Atlantic should gradually
see some heat relief as a cold front progresses south late week into the
weekend, but the central U.S. will remain hot. Meanwhile, temperatures
will be below average across the West given the upper low overhead. In
fact, below freezing morning temperatures are expected across the higher
elevations as far south as northern California.


Kong/Tate


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

Extreme Heat Key Messages available at:
https://www.wpc.ncep.noaa.gov/basicwx/basicwx...

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