154
FXUS01 KWBC 150807
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Wed Jul 15 2026

Valid 12Z Wed Jul 15 2026 - 12Z Fri Jul 17 2026

...Additional excessive rainfall likely across the Texas Hill
Country...

...Anomalous heat and humidity continuing across the Northern
Plains/Upper Midwest while spreading into the northern
Mid-Atlantic...

...Monsoonal showers and thunderstorms develop across the interior
western U.S...

...Severe thunderstorms possible early this morning across
northern New England and portions of Montana; strong thunderstorms
return on Thursday across northern New England...

An unusually strong upper-level high has become nearly stationary
over the northern tier states while building southeast toward the
East Coast.  This weather pattern will prolong the heat and
humidity across the Northern Plains to the Great Lakes where high
temperatures will remain in the 90s to lower 100s for the next few
days.  A cold front trailing from a deepening cyclone across
eastern Canada will bring some cooler and drier air into the
U.S.-Canadian border and keep the temperatures in the 80s there.
Meanwhile, the heat and increased humidity will return to the
northern Mid-Atlantic today and Thursday when triple digit high
temperatures are expected at the hottest locations.  Extreme Heat
Warnings remain in effect across portions of the Northern Plains
as Heat Advisories are posted for much of the Great Lakes,
portions of New England and some Extreme Heat Warnings over the
northern Mid-Atlantic.  If you will be situated within any of
these areas forecast to experience extreme heat, stay hydrated,
take frequent breaks, and limit outdoor activities if possible.
Severe thunderstorms are possible early today across northern New
England ahead of the the cold front, and across Montana on the
backside of a low pressure wave near the western end of the end.
Cooler air will penetrate deeper into New England by Thursday
morning under gusty westerly winds behind the cold front followed
by a reinforcing shot of cooler air by Friday morning with the
passage of a second cold front.  In addition, some strong
thunderstorms are possible later on Thursday across northern New
England prior to the arrival of the second cold front.

As the anomalous upper high extends across the northern tier, a
slow-moving weather regime has already set up across the southern
tier states.  A nearly stationary front will also be sprawled from
the Southern Plains to the Southeast during this period.
Upper-level vortices will likely interact with the wavy frontal
boundary to produce repeated rounds of showers and thunderstorms
for the southern states.  Near the western end of the front, a
significant heavy rainfall event is forecast to linger across the
Texas Hill Country over the next three days as clusters of
thunderstorms could mutually amplify the smaller scale upper-level
vortices to further enhance rainfall over this region under this
slow-moving weather pattern.  The latest rainfall forecast calls
for storm total rainfall amounts of 6-8" with locally 10+ inches
possible over the next couple of days, which could lead to
dangerous flash flooding as soils in the area become increasingly
inundated.

Meanwhile, the forecast remains on track for an influx of
monsoonal moisture to drive an uptick in late-day to early-evening
thunderstorms over the Four Corners, Intermountain West, and the
eastern portion of the Great Basin.  Scattered thunderstorms are
also forecast from the Deep South to the Southeast near the
stationary front, which will be lifting farther north into the
Mid-Mississippi and Ohio Valleys later on Thursday.  A few
instances of flash flooding and severe weather are possible in the
strongest storms through midweek.


Kong/Campbell/Asherman/Otto


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




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