Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Sat May 27 2023

Valid 12Z Sat May 27 2023 - 12Z 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 into
the Mid-Atlantic through the Memorial Day weekend...

...Showers and thunderstorms expected to linger across the Great Basin,
northern and central Rockies, and especially 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 sluggish upper level pattern is forecast to persist across the
continental U.S. through the Memorial Day weekend as another elongated
upper trough dips into the West Coast.  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.  This will
trigger showers and thunderstorms across the Great Basin into the northern
Rockies of Montana; while strong to severe thunderstorms will be most
active from late afternoon into the evening hours from southeastern
Montana through the western Panhandle of Texas through the Memorial Day
weekend.  The Storm Prediction Center had issued an Enhanced Risk of
severe weather with a better potential for tornadoes as well as severe
hail/winds over the southern High Plains early this morning.  The severe
weather risk will become more limited in coverage and intensity for the
rest of today and for the next couple of days through the length the High
Plains, with the best potential within a Slight Risk across the northern
High Plains.  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 northern Montana today 
with a broad Marginal Risk in connecting areas through the length of the 
High Plains and northern Rockies.  The severe weather and heavy rain 
potentials are expected to shift only slightly eastward but again cover 
the length of the High Plains Sunday into Monday morning.

Meanwhile, a low pressure system has exited Florida and is moving over the
Atlantic waters off the coast of the southeastern U.S.  This system has
been gathering some strength over the warm waters off Florida and Georgia
as the center heads north toward the Carolinas early this morning.  Bands
of heavy rain forming ahead of the low pressure center are expected to
push onshore today with strengthening winds prior to the arrival of the
low center by Sunday morning.  Coastal communities across the Southeast
can expect strong and gusty winds, high surfs, in addition to life
threatening rip currents for much of the weekend.  Boating conditions will
also be quite treacherous with a Storm Warning issued by the Ocean
Prediction Center/NWS Forecast Office in Charleston for the offshore
waters of the Carolinas.  Meanwhile, squally showers and thunderstorms are
expected to spread inland with high rainfall potential.  A Moderate Risk
of Excessive Rainfall has been issued by WPC for parts of the NC/SC
coastal plain today, while a broader Slight Risk engulfs 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.  By Sunday, the low
pressure system is forecast to gradually weaken after its center makes
landfall near the NC/SC border early on Sunday.  Nevertheless, heavy
rainbands on the outer portion of the storm are now forecast to push
northward across Virginia on Sunday.  Slow improvement in the weather is
anticipated into Monday morning but cloudy and rainy conditions are
expected to cover much of the Mid-Atlantic early on Memorial Day.

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.

Kong/Gallina


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