Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 PM EDT Thu Aug 04 2022

Valid 00Z Fri Aug 05 2022 - 00Z Sun Aug 07 2022

...Monsoonal rains over the western U.S. expected to shift eastward as
thunderstorms ahead of a cold front could bring heavy rain into the upper
Midwest on Saturday...

...Heat expected to spread across the northern tier while remaining in
place over the Northeast for the next couple of days...

...Cool air spreading into the Pacific Northwest will lower the fire
threat across the northern Rockies to the northern High Plains...

A cool air mass will bring a noticeable break in the heat from the Pacific
Northwest eastward into the northern Plains during the next couple of
days, as no significant changes in the hot summer pattern is expected for
much of the rest of the country.   Southwesterly flow ahead of the cool
air mass will guide the monsoonal moisture that has been hovering over
much of the interior western U.S. toward the northern Rockies, reaching
into the northern Plains by Friday.  The advancing cold front is expected
to trigger thunderstorms across the northern Plains on Friday before
reaching into the upper Midwest and Saturday.  It appears that the
thunderstorms could become organized over the upper Midwest later on
Saturday where heavy rain is possible as a low pressure wave is forecast
to develop over the central Plains.  Meanwhile, monsoonal showers and
thunderstorms will remain the rule farther south over the Great Basin and
the Four Corners region with a tendency for the activities to shift
eastward across the central and southern Rockies by the weekend.  Across
the northern Rockies into the High Plains, monsoonal moisture drawn
northward ahead of the cool air mass will be interacting with the
associated front to result in some locally heavy rainfall late Friday into
Saturday.

Over the eastern third of the country, an old front will remain be the
focus for thunderstorms and locally heavy rain mainly from the
mid-Mississippi Valley to along the Ohio Valley through tonight, shifting
eastward toward the interior Mid-Atlantic by Friday where a low pressure
trough is forecast to persist. By Saturday, the front is forecast to lift
northward through New England as a warm front but scattered thunderstorms
are expected to remain across much of the eastern U.S.

Heat is expected to spread across the northern tier ahead of the cool air
mass as high temperatures soar into the upper 90s to low 100s.  The
Northeast and Mid-Atlantic will remain hot ahead of the approaching upper
trough.  Record breaking highs in upper 90s this afternoon will be less
extreme by Friday and Saturday as cloud cover increases.  As the bubble
high stationed over the central U.S. lifts north on Friday, so too will
the heat. Record breaking high temperatures in the upper 90s and 100s are
forecast across the Northern/Central Rockies as a result. The heat in the
northwest paired with windy and dry conditions will contribute to fire
concerns across portions of Montana today and Friday where a Critical Risk
of Fires was issued by the Storm Prediction Center. Red Flag warnings are
in effect for much of Montana as well.

Kong

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