Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
328 PM EDT Sat Aug 16 2025

Valid 00Z Sun Aug 17 2025 - 00Z Tue Aug 19 2025

...Rounds of severe thunderstorms with heavy rain possible over the
northern Plains and Upper Midwest through Monday...

...Turning cooler across the Northeast Monday into Tuesday in the wake of
a cold front that could spark a few severe storms on Sunday...

...Hazardous heat builds across parts of the Midwest and Mid/Lower
Mississippi Valley through early next week...

A frontal system stretching from the Pacific Northwest, to the Upper
Midwest, to the Northeast and eventually the Mid-Atlantic will continue to
be the focus for showers and thunderstorms the next few days. This wavy
front will be the divider between cool and dry air to the north, and very
warm and humid air to the south, particularly east of the Rockies. Several
waves developing along this boundary will keep its forward motion
relatively slow across the northern Plains and Upper Midwest, setting the
stage for repeated rounds of heavy rain and strong to severe
thunderstorms. The slow motion of the front combined with storms tracking
over the same areas multiple times will lead to the potential for isolated
to scattered instances of flash flooding through Sunday, especially for
parts of the eastern Dakotas, the southern half of Minnesota and
Wisconsin, northern Iowa and northern Illinois. The severe and flooding
threats wane somewhat on Monday, but won't diminish completely until
Tuesday when high pressure building into the region finally dries things
out. Until then, those who are under the threat of flash flooding the next
few days are advised to plan ahead before venturing out, and be aware of
alternate routes in case you encounter flooded roadways. Remember, Turn
Around, Don't Drown!

The aforementioned frontal system will be much more progressive across the
eastern Great Lakes, Northeast, and Mid-Atlantic, sweeping into a very
warm and humid air mass Sunday into Monday. As the front pushes through,
isolated to scattered thunderstorms are likely to develop, with a few
possibly becoming strong to severe. Any strong to severe storm will be
capable of producing isolated damaging wind gusts, with hail also not
ruled out. Other than the marginal severe threat, the big story will be
the cooler and drier air that filters into the region in the wake of the
front, providing a much more pleasant start to the new work week after a
steamy weekend.

Elsewhere, precipitation chances will persist through the weekend for
portions of the Southwest and Southeast. Monsoonal moisture across the
Four Corners region will support daily afternoon and evening scattered
showers and thunderstorms, while a weak area of low pressure and trailing
frontal boundary lingering just off the Southeast Coast will produce
scattered showers and thunderstorms across parts of the Carolinas, Georgia
and Florida. While widespread flooding concerns are not expected in these
areas, any slower moving or heavier shower or storm will be capable of
causing isolated instances of flash flooding, particularly over more
sensitive areas like burn scars, steep terrain, or areas of poor drainage.

To the south of the frontal system oscillating across the northern tier of
the U.S., a period of scorching heat is likely to build for parts of the
Midwest and the Mid/Lower Mississippi Valley through early next week. High
temperatures are forecast to range from the 90s to near 100 degrees with
heat index values of 105-110 degrees. This level of heat will create Major
to Extreme HeatRisk across the region, which could be dangerous to anyone
without adequate cooling and/or hydration.

  
Miller


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