Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Mon Sep 06 2021

Valid 12Z Mon Sep 06 2021 - 12Z Wed Sep 08 2021

...Late-summer heat forecast to dominate much of the West...

...Fine weather across the mid-section of the country but showers and
thunderstorms along the Gulf Coast and across the northern tier states ...

The Labor Day weekend will end with a relatively tranquil note as no
widespread areas of heavy rain or stormy conditions are anticipated today.
Only isolated to scattered thunderstorms are forecast across the Deep
South and the Mid-Atlantic region as a relatively dry cold front passes
through.  Nevertheless, some brief periods of heavy rain are possible with
the strongest storms.  Meanwhile, widely scattered showers are exiting New
England as the northern portion of the cold front moves east into the
Canadian Maritimes by tonight.  A reinforcing cold front will also bring
some widely scattered showers and thunderstorms from the lower Great Lakes
this morning followed by northern New England by tonight.  By Tuesday,
another upper trough dipping across central Canada will trigger the
development a new low pressure system near the U.S.-Canadian border.  Some
showers and thunderstorms are expected to move across the upper Midwest
into the Great Lakes near/ahead of this system.  The thunderstorms could
become quite strong across the lower Great Lakes Tuesday evening as the
low pressure system intensifies.  By Wednesday morning, these
thunderstorms will be moving towards New England.

Mainly fine and dry weather is expected to continue across the mid-section
of the country for the next few days.  This dry pattern will be reinforced
and extended into the western U.S. as an upper level ridge is forecast to
expand and remain anchored over the region.  High temperature departures
will range between 10-20 degrees above normal under this expanding ridge. 
Some locations in the Desert Southwest are under Excessive Heat Warnings
due to daytime highs 105-115F with some spots even surpassing 115F.  Heat
Advisories are also in effect for much of California's Great Valley and a
large chunk of Southern California.  By Tuesday, the heat will continue to
build even more in the Great Basin and Intermountain West where a handful
of daily record high temps could be tied and/or broken. The large area of
high pressure aloft will keep the West dry as well, meaning little relief
is expected to come for ongoing wildfires.  In fact, there are Elevated
Risks for favorable fire weather conditions in the northern Rockies and
High Plains.  Expect large swaths of wildfire smoke to blanket much of the
West and parts of the Plains with some Air Quality Alerts posted from the
West Coast to the Rockies.

Kong/Mullinax