Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
359 PM EDT Wed Jul 18 2018

Valid 00Z Thu Jul 19 2018 - 00Z Sat Jul 21 2018

...There is a slight risk of severe thunderstorms over parts of the
Central Plains...

...Heavy rain possible over parts of the Upper Mississippi and the Middle
Missouri Valleys...

...Heavy rain possible over parts of the Southeast Coast and the Eastern
Gulf Coast...

A quasi-stationary front extending from the Southern Mid-Atlantic into
parts of the Southern Plains will slowly dissipate over the Southern
Plains/Lower Mississippi Valley by Thursday night, while the boundary over
the Southeast remains but stalls. This front will be the epicenter for
shower and thunderstorm development across the Southeast and southern
Mid-Atlantic coast through the end of the work week.

Meanwhile, a low pressure system currently over the Central Plains will
continue to deepen as it shifts east-northeastward through the Northern
Plains and towards the Upper Mississippi Valley by the end of the work
week. As this low deepens, a strong pull of warm, moist air from the Gulf
of Mexico will result in the development of a fairly strong warm front,
and then eventually a cold front. This system will also be the epicenter
for shower and thunderstorm development across this region. The Storm
Prediction Center has outlined an enhanced risk for severe thunderstorm
development across portions of the Central and Northern Plains for this
afternoon through tonight. A marginal and slight risk have also been
outlined across portions of the Mid Mississippi Valley for Thursday,
shifting eastward into the Ohio Valley for Friday ahead of the developing
cold front. Excessive rainfall and flash flooding will also be possible
with these storms. The Weather Prediction Center has also outlined
portions of the northern Missouri River Basin as being in a marginal to
slight risk of excessive rainfall this afternoon and tonight. Portions of
the Upper Mississippi River Valley have a marginal to slight chance of
excessive rainfall on Thursday as well.

In addition to the thunderstorm and excessive rainfall concerns, heat is
also impacting many states across the U.S. A strong pull of warm air into
the central portion of the United States is currently leading to well
above normal temperatures in addition to high humidity values. This will
only increase as the above mentioned low pressure system continues to gain
strength. Portions of the Southern Plains, as well as some locations in
Nebraska and Missouri are under Heat Advisories and Warnings through the
end of the work week as a result. Furthermore, much of the western United
States is also feeling the effects of excessive heat. Excessive heat
watches, advisories, and warnings are all in effect across California,
portions of the extreme Southeast, and the Central Great Basin. Wind is
aiding to the problem farther north, with Red Flag Warnings posted across
portions of the Northwest and into the Northern Rockies.

Ziegenfelder


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