Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
418 AM EDT Sun Jun 17 2018
Valid 12Z Sun Jun 17 2018 - 12Z Tue Jun 19 2018
...Severe thunderstorms and flash flooding continue for parts of the Upper
Midwest on Sunday and Monday...
...Continued rain and thunderstorms for the Great Basin and Northern and
Central Rockies through Monday...
...Dangerously hot conditions for the Midwest and Ohio Valley on Sunday
and the East Coast on Monday...
A slowly moving front stretching from the Midwest through the Plains and
into the Rockies and Central Great Basin will be the main weather causer
over the next couple of days. For the Midwest and the Plains, heavy rain
and severe thunderstorms are likely on Sunday and will persist into
Monday. Slight risks of flash flooding and severe weather are in place
across the Central Plains into the Upper Midwest on Sunday. An embedded
moderate risk of excessive rainfall is in effect for northern Wisconsin
and portions of Upper Michigan, where heavy rainfall has already fallen
over the past day or so. The eastern part of the front currently in Canada
will push southward into the northeastern U.S. by Monday evening, leading
to rain and the possibility of flash flooding and strong thunderstorms
there as well.
Farther west, an upper-level trough plus the stationary front will lead to
rain and thunderstorms for the Great Basin into the Northern and Central
Rockies region. Heavy rainfall is possible, particularly for the Northern
Rockies, where there is a slight risk of flash flooding in effect on
Sunday and Sunday night. Cooler than average temperatures will be in place
in those areas.
South of the front, hot temperatures combined with high humidity will lead
to heat indices over 100 degrees in the central and eastern U.S.
Widespread Heat Advisories are in effect for the Middle Mississippi Valley
and portions of the Ohio Valley and Upper Great Lakes region on Sunday.
Excessive Heat Warnings are in effect for the cities of Chicago and St.
Louis. Heat will build in the Mid-Atlantic and Northeast by Monday, with
record high temperatures well into the 90s possible there.
Elsewhere, a trough of low pressure combined with tropical moisture near
the Texas coast will produce heavy rainfall there by Monday. There is a
slight chance of flash flooding along the Texas coast on Monday, and more
rain is expected Tuesday, so continue to monitor subsequent forecasts.
Scattered thunderstorms are possible throughout the Southeast through the
beginning of the week, but are not expected to be severe or cause
widespread flash flooding.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php