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