Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
357 PM EDT Thu Jul 18 2019
Valid 00Z Fri Jul 19 2019 - 00Z Sun Jul 21 2019
...A dangerous heat wave is building in the central and eastern U.S....
...Severe weather and flash flooding are both possible for the Upper
Midwest this evening...
An upper-level ridge is building over the southeastern U.S., setting the
stage for what will be a miserably hot and humid weekend for millions of
Americans. The sprawling area of high pressure will drive hot and humid
air north and east from the Gulf through the Northeast. Daytime
temperatures will soar into and through the 90s from the Plains eastward,
and overnight minimums in the 70s and 80s will provide little relief. Heat
Advisories, Excessive Heat Watches, and Excessive Heat Warnings are in
effect for the Plains, Mississippi and Ohio Valleys, and the Eastern
Seaboard. Dozens of record high minimum temperatures are forecast to be
set across the eastern U.S., and a handful of record high maximum
temperatures will be challenged. The heat wave is expected to persist
through the weekend across the east, but a cold front ushering in cooler
air will march across the U.S. as an upper-level trough begins to build
near Hudson Bay.
Scattered thunderstorms are expected along fronts moving through the
north-central U.S., a few of which could be severe and produce heavy
rainfall. Slight Risks of both severe weather and excessive rainfall are
in place this evening for parts of the Great Lakes region, with more
storms possible across the Upper Midwest tomorrow. Today, a Slight Risk
for excessive rainfall remains for the northern Mid-Atlantic, tied to
moisture from the remnants of Barry.
Elsewhere, the trough responsible for the cooler temperatures and lower
relative humidity in the Northwest will also raise concerns for fire
weather conditions throughout the Intermountain West.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php