Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
216 PM EDT Fri May 26 2023

Valid 00Z Sat May 27 2023 - 00Z Mon May 29 2023

...A low pressure system is forecast to bring areas of heavy rain, gusty
winds and hazardous beach and boating conditions for the Southeast over
the Memorial Day weekend...

...Showers and thunderstorms expected to linger across the Great Basin,
northern and central Rockies, and the High Plains for the next few days...

...Warmer than normal across much of the Northwest and north-central U.S.
but much cooler than normal across the Mid-Atlantic and Southeast...

A very slow blocky upper level pattern is forecast to persist across the
continental U.S. through the Memorial Day weekend.  An elongated north to
south trough of low pressure will exist in the west, but embedded stronger
jet streaks will help to produce surges of dry air out of the Southwest
while drawing above normal moisture up through the length of the High
Plains on Friday evening.  This will trigger showers and thunderstorms
across the Great Basin into the Northern Rockies of Montana; while strong
to severe thunderstorms are expected to develop from southeast Montana
trough the Western Panhandle of Texas.  The Storm Prediction Center has
issued a Slight Risk from MT through eastern WY and eastern CO, with a
risk of severe winds and hail being the highest potential.   Further south
across southeast NM into West Texas Panhandle, an Enhanced Risk of severe
weather exists, with a better potential for tornadoes as well as severe
hail/winds.  By Saturday, the risk is more limited in coverage and
intensity though should span the length the High Plains again, with the
best potential within a Slight Risk across Eastern WY into SDak/W Neb.  
Some of these thunderstorms will be slow moving and have the potential for
very high rainfall rates.  As such, the Weather Prediction Center has a
Slight Risk of Excessive Rainfall for Friday over much of E MT, parts of
northeast WY and portions of eastern New Mexico into the Cap Rock on
Friday and eastern MT on Saturday with broad Marginal Risk in connecting
areas through the length of the High Plains and Northern Rockies on both
days. 


Meanwhile, a low pressure system that has been developing over Florida
will bring deteriorating weather across the Southeast for the Memorial Day
weekend.  This system will have a chance to gather some strength over the
warm waters off Florida and Georgia as it heads north toward the Carolinas
on Saturday before moving west into the Carolinas by Sunday morning.
Strong winds and anomalous moisture will help to strengthen the low,
generating high waves making for beach and boating activities to be quite
hazardous.  High Surf Advisories have been posted for portions of Georgia
and South Carolina coasts already, life threatening rip currents are to be
expected for much of the Southeast.  Boating conditions will also be quiet
treacherous with a Storm Warning issued by the Ocean Prediction Center/NWS
Forecast Office in Charleston and parts of SC offshore waters with a broad
Gale Warning up through the Florida East Coast to southeast VA/North
Carolina waters. Onshore conditions will not be much fun as well, strong
showers and thunderstorms should be numerous with high rainfall potential.
 A Moderate Risk of Excessive Rainfall has been issued by WPC for parts of
the SC/NC Coastal Plain for Saturday, while a broader Slight Risk extends
across much of the Carolinas, so instances of flash flooding will be
possible.  The areal coverage of showers/thunderstorms will result in a
very cloudy day on Saturday, with numerous record low Maximum temperatures
expected with highs in the 50s in the upstate SC and parts of NC and only
60s in the Low Country, generally 20 to 30 degrees below average.

Elsewhere, across the Mississippi Valley, Great Lakes, Northeast and
Southwest should have a very pleasant weekend.  Temperatures will be
average for much of the southern portion of the central U.S.; though the
northern tier, particularly the Plains and Upper Great Lakes will see
above normal but not oppressive temperatures in the 70s and 80s for both
Friday through Sunday.

Gallina

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