Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
308 AM EDT Sat Jul 22 2017

Valid 12Z Sat Jul 22 2017 - 12Z Mon Jul 24 2017

...Flash flooding and severe weather will be possible over portions of the
Ohio Valley and Mid-Atlantic states this weekend...

...Another day of dangerous heat is expected from the Central Plains and
Middle Mississippi Valley to the Mid-Atlantic coast on Saturday...

...Monsoonal moisture will keep localized flash flooding a threat from the
Southwest to the Southern and Central Rockies over the next few days...

A wavy frontal boundary stretching from the Central Plains to the
Mid-Atlantic coast early Saturday will continue to serve as a focus for
showers and thunderstorms while it gradually sinks southeastward this
weekend.  An abundance of moisture and instability along and south of the
boundary could lead to heavy downpours and severe weather within
developing convection, especially for locations across the Ohio Valley and
northern Mid-Atlantic states on Saturday.  Strong to severe storms will
also be possible farther north over the Upper Mississippi Valley and Great
Lakes as amplifying shortwave energy progresses from the Northern Plains
to Interior New England this weekend.

Hot and humid conditions will persist for locations south of the wavy
frontal boundary stretching from the Central Plains to the Mid-Atlantic
coast.  Widespread excessive heat warnings and heat advisories remain in
effect for much of the Central to Southern Plains, Middle to Lower
Mississippi Valley, and southern Mid-Atlantic states, where the dangerous
combination of high temperatures and dew points will lead to triple digit
heat index values on Saturday.  Locations across Kansas and Missouri
should begin to see relief from the heat as the wavy frontal boundary
sinks through the region Saturday night, but elsewhere, the dangerous heat
will persist into Sunday.

Weak impulses of energy aloft combined with monsoonal moisture should help
trigger and fuel scattered convection over the Southwest and Southern to
Central Rockies Saturday and Sunday afternoon and evening.  Localized
flash flooding will be possible given the anomalous moisture in place
across the region.


Gerhardt


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