Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
407 AM EDT Sun Sep 05 2021

Valid 12Z Sun Sep 05 2021 - 12Z Tue Sep 07 2021

...Occasional showers and storms from the mid-South to the the Northeast
while raging wildfires continues out West causing poor air quality
downstream...

...Seasonally cool from the Central Plains to Northeast but hot and humid
across the southern Plains and Southeast; increasingly hot throughout the
West...

An upper-level trough dipping into the Great Lakes will help push a
sluggish cold front over the mid-section of the country faster towards the
east.  Some of the thunderstorms ahead of this front could be quite strong
across the mid-Mississippi Valley where heavy downpours from these
thunderstorms can result in localized areas of flash flooding early this
morning.  The front should then continue to move steadily across the
Northeast and the Mid-Atlantic states on Labor Day, with its trailing
portion dipping across the Deep South.  Scattered thunderstorms can be
expected to move into the Deep South, the Appalachians and the Northeast
today as well as today.  By Labor Day, the front will likely bring
isolated to scattered thunderstorms across the Mid-Atlantic while
scattered thunderstorms continue across the Deep South.  New England
should see the thunderstorms ready to exit the region early on Labor Day
before cooler and drier air arrives behind the cold front.  However, a
reinforcing cold front will spread scattered showers and some
thunderstorms from the Great Lakes into northern New England later on
Labor Day.  Fine and pleasant weather will prevail from the
northern/central Plains eastward to the Ohio Valley today and Labor Day. 
But another upper trough from central Canada will help develop a low
pressure system over the northern Plains on Labor Day, bringing the next
round of showers and thunderstorms into the upper Midwest later on Labor
Day, moving into the Great Lakes Tuesday morning.

Temperature-wise, the West continues to heat up as a building ridge of
high pressure becomes centered over Nevada and central California on Labor
Day. Beneath this intensifying ridge aloft, afternoon heat will envelop
much of the West Coast with the hottest conditions focused in central
California and the Great Basin.  Excessive Heat Watches remain posted for
much of the Mojave Desert where high temperatures soaring into the 110s
are likely starting Labor Day and continuing into Tuesday. Heat Advisories
are also in effect in the San Joaquin Valley for Labor Day as well. The
heat across the West is expected to spread into the northern High Plains
by Labor Day where high temps look to range between 10-15 degrees above
normal.  Meanwhile, sultry conditions continue throughout south Texas and
into the Lower Mississippi Valley this afternoon and into Labor Day.  The
aforementioned cold front described above will help cool the South-Central
U.S. to more seasonal levels by Tuesday.

Elsewhere, a quasi-stationary front lingering near the northern Gulf Coast
and over central Florida begins to dissipate by Labor Day.  Daily rounds
of pop-up showers and storms each afternoon can be expected with some of
the storms containing heavy downpours. One more day of scattered showers
and storms are on tap in southern New Mexico and into the Texas Panhandle
today but should decrease in coverage and intensity by Labor Day. Lastly,
Air Quality Alerts remain in effect across parts of the Pacific Northwest
and California due to ongoing bouts with smoke from ongoing wildfires.

Kong/Mullinax