Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Sun Jul 19 2026

Valid 12Z Sun Jul 19 2026 - 12Z Tue Jul 21 2026

...Additional Canadian wildfire smoke to move south across the Great Lakes
into the Mid-West; air quality issues continue in the Pacific Northwest...

...Frontal system to drive thunderstorms from the Northern Plains to the
Mid-Atlantic today and tomorrow...

...System over the northeast Gulf may bring heavy rains to coastal
sections of the eastern Gulf...

...Monsoonal thunderstorms continue over the next few days from the
Southwest into the Great Basin...

...Hazardous heat builds from the Northern Plains into the Lower
Mississippi Valley...

The ongoing wildfires across western portions of Ontario will continue to
be a source of wildfire smoke affecting portions of the CONUS this weekend
into next. The latest batch of smoke over the Great Lakes and Midwest is
expected to linger into early next week, where Air Quality Alerts are in
effect from Minneapolis to Cleveland today. Additional air quality issues
will persist over interior portions of the Pacific Northwest into tomorrow
owing to numerous wildfires in the region.

Meanwhile, a front extending from the Northern Plains into the
Mid-Atlantic will serve as a catalyst for thunderstorm development today.
Within this broad area, two separate corridors in the Northern Plains and
lower Mid-Atlantic are being monitored for flash flooding and severe
weather within the strongest cells today and tomorrow. In the northeast
Gulf, a slow moving disturbance (now with a 60% chance of tropical cyclone
formation per NHC) could bring heavy rains and at least isolated flash
flooding to coastal sections of the eastern Gulf over the next few days.
In the West, daily monsoon thunderstorms capable of locally heavy rainfall
and scattered flash flooding will continue across the Desert Southwest and
Great Basin into midweek. 

Temperature wise, a dome of high pressure building across the Nation's
midsection will support a bout of much above normal temperatures today and
tomorrow across the Northern Plains, Lower Missouri Valley, and Lower
Mississippi Valley. Widespread Heat Advisories are in effect in these
areas, where heat indices of 100-105 can be expected over the next day. By
midweek, the arrival of a fairly strong cold front should usher in relief
to the Plains and Midwest, where high temperatures should dip below
normal.

Asherman

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