Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
358 PM EDT Fri Aug 18 2017
Valid 00Z Sat Aug 19 2017 - 00Z Mon Aug 21 2017
...Slight risks of severe thunderstorms and flash flooding for the
portions of the Midwest and Mid-Atlantic on Friday afternoon and evening...
...Heavy rain and flash flooding possible over parts of the Southwest this
...Slight risks of severe thunderstorms and flash flooding for portions of
the Northern Plains/Upper Mississippi Valley...
A surface low pressure system will continue to pass through the Ohio
Valley, Mid-Atlantic and Northeast regions this weekend which will
generate scattered to widespread showers and thunderstorms. Some of these
storms will be well organized, potentially becoming severe and producing
periods of heavy rain. The Storm Prediction Center has identified portions
of Missouri, Minnesota and the Mid-Atlantic as having a a slight risk for
severe thunderstorms through late tonight. Showers and thunderstorms will
persist from the Southeast to the Mid-Atlantic as the trailing end of the
front stalls over the region.
An upper-level low will move over the southwest U.S. this weekend. Ample
moisture streaming into the Southern Plains and Southwest will trigger
widespread convection as it interacts with stationary boundary then lifts
as a warm front into the Southern/Central Plains. Much of the Mongolian
Rim, Southern and Central Rockies and the surrounding valleys will have an
increased risk for heavy rainfall and flash flooding this weekend. Areal
averages of 1 to 2 inches are forecast for much of New Mexico over the
next few days - localized amount near 3 inches may be possible.
A cold front will pass through the Intermountain West through Saturday
morning before tracking across the Northern High Plains and Upper Midwest
Sunday into Monday. Additional showers and thunderstorms will spread
across the northern tier states this weekend. Heavy rain and flash
flooding will be possible Sunday afternoon and evening for portions of
southern Minnesota and northern Iowa.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php