271
FXUS01 KWBC 170800
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
359 AM EDT Fri Jul 17 2026

Valid 12Z Fri Jul 17 2026 - 12Z Sun Jul 19 2026

...Heavy rainfall threat continues in the Texas Big Bend today;
dangerous flash flooding remains possible...

...Daily monsoonal showers and thunderstorms continue across the
Western U.S. this weekend; stormy weather expected over parts of
the Northern Tier and Mid-Atlantic

...Air quality alerts span from the Upper Midwest Great Lakes to
New England...

...Heat and humidity persists across the Northern Plains/Upper
Midwest; lingers in the Mid-Atlantic through tomorrow...

A slow-moving weather regime continues across the Southern Tier
states as an upper-level low near the Texas Big Bend slowly
retrogrades towards the Desert Southwest. This upper-level low
(one key ingredient in the catastrophic Texas flash flooding) is
forecast to meander northwestward today, which will lessen the
coverage of showers and thunderstorms in central Texas this
weekend. Unfortunately, the slow movement of this upper-level low
and associated moisture mean that scattered pockets of very heavy
rain remain possible today near the Texas Big Bend, which would
exacerbate the dangerous flooding from the last few days of
extreme rainfall. Meanwhile, monsoonal thunderstorms capable of
isolated to scattered severe weather flash flooding are forecast
to track from north to south across the Four Corners region today
and tomorrow under the influence of the aforementioned southern
High Plains upper-low. Along the Northern Tier, a transitory
frontal system will also drive daily showers and thunderstorms
this weekend, some of which could produce scattered severe weather
from the Ohio Valley into the Mid-Atlantic tomorrow.

Hot and humid conditions expected to persist across the Great Lake
and Northern Plains for several days with daily highs in the 90s
to lower 100s expected. Air quality also remains a concern this
weekend as northwesterly flow continues to usher in smoke from
Canadian wildfires toward the northeastern quarter of the Nation.
Meanwhile, another day of triple-digit high temperatures and
elevated humidity is expected for the northern Mid-Atlantic today
before temperatures moderate with the frontal passage this
weekend.

Asherman/Campbell


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




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