Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
353 AM EDT Sun Aug 19 2018
Valid 12Z Sun Aug 19 2018 - 12Z Tue Aug 21 2018
...Heavy rainfall and strong thunderstorms expected to impact parts of the
Plains and Mississippi Valley...
...Air quality will remain a concern across portions of the Western U.S.
and the Upper Midwest...
A low pressure system in the southern Plains will lift into the central
Plains and middle Mississippi Valley today. Heavy rain already impacting
the central and southern Plains will continue to move eastward today
across these areas and move into the middle and lower Mississippi Valley
by this evening. Farther north, a cold front will press southward along
the northern Plains and Upper Mississippi Valley. Showers and
thunderstorms are expected to develop along and ahead of the front--which
will be capable of producing flash flooding. A slight risk of flash
flooding is possible for parts of northern Plains in addition to portions
of the central and southern Plains. There is also a marginal risk of
severe weather for the southern Plains and into the lower Mississippi
Valley. As this system slides from the Mississippi Valley into the Ohio
Valley, showers and thunderstorms will develop in Iowa on Monday afternoon
and will progress into southern Wisconsin and northern Illinois. By
Tuesday morning, showers and thunderstorms will increase throughout the
Great Lakes, Ohio Valley southward into the lower Mississippi Valley.
Fire weather continues to remain a concern across the western U.S. The
combination of high winds, low humidities, and the threat of low
precipitating thunderstorms may contribute to igniting wildfires. Due to
the ongoing wildfires, Air Quality Alerts remain in place for the Pacific
Northwest, northern Montana and a small portion of the Southwest due to
smoke pollution. In addition, wildfires in Canada are also advecting
smoke southward across the Upper Midwest, resulting in Air Quality Alerts
for much of Minnesota as well.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php