Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
258 PM EST Fri Feb 10 2023

Valid 00Z Sat Feb 11 2023 - 00Z Mon Feb 13 2023

...Mixed precipitation and heavy snow over northern Maine today will
gradually taper off tonight...

...Heavy rain, strengthening winds, and possibly severe thunderstorms are
expected to expand across the Southeast on Saturday...

...Heavy wet snow, sleet and some freezing rain is expected to develop
near/over the central and southern Appalachians Saturday night into Sunday
morning...

A low pressure system moving eastward through southern Ontario will
continue to deliver mixed precipitation across northern New England and
heavy snow across northern Maine today. Mixed wintry precipitation is
expected to taper off and change over to light snow by tonight following a
cold frontal passage. Some lake-effect snow is forecast to linger a bit
longer in areas downwind from the lower Great Lakes into Saturday morning
before drier air arrives from the west.

To the south of the wintry weather, temperatures have been very warm, with
widespread record high maximum temperatures occurring along the entire
East Coast. Southerly flow ahead of an incoming cold front is ushering in
warm and moist air, creating spring-like conditions across the East Coast.
Much of the East Coast will be noticeably cooler tonight following a cold
frontal passage. However, temperatures will still be above average by
February standards.

Meanwhile, a strengthening low pressure system over the Gulf of Mexico
will begin to set the stage for increasingly stormy weather across the
Southeast, including some wet snow and/or sleet for portions of the
southern and central Appalachians. Southerly flow aloft will transport
moisture toward the Gulf Coast, and with the primary front expected to
stall over the Gulf, prolonged rain is in store for much of the Southeast.
The initial threat of heavy rain will be confined to the Florida
Panhandle. However, as an upper low moves toward the lower Mississippi
Valley today, moist low level flow will strengthen out of southwest and
south off the central to eastern Gulf of Mexico, supporting an expanding
area of heavy rainfall rates from the central Gulf coast northeastward.
Areas of the Florida Panhandle, southeastern Mississippi, southern
Alabama, southern Georgia, and southern South Carolina will be wet in the
short term. This is welcome precipitation, as much of this region has seen
average to below average precipitation amounts over the past few weeks.
Dry antecedent soil should help to mitigate some flash flood potential.
However, WPC has issued a Slight Risk for Excessive Rainfall for portions
of the central Florida Panhandle and into far southern Georgia, where high
rainfall rates are currently occurring and storm-total precipitation may
exceed 4-5".

By Saturday evening and into early Sunday, the low pressure system is
forecast to move across northern Florida into the Atlantic Ocean while it
continues to intensify. Heavy rain, strengthening winds, and possibly
severe thunderstorms are expected to expand across the Southeast beginning
on Saturday along with the low pressure system. The Storm Prediction
Center has issued a Slight Risk of severe thunderstorms across portions of
the Florida Panhandle on Saturday. The primary threat from these
thunderstorms is expected to be damaging wind gusts.

As the system continues to move along the East Coast, heavy wet snow
and/or sleet is expected to develop near/over the central and southern
Appalachians. Given the dynamic nature of this system and the moderate
airmass in place, accumulating snowfall may be limited to the upslope
regions of the Appalachian Mountains, where there is a 50-80% chance of
snow accumulating 4"+. In addition to the snow, warm air aloft will bring
a risk of icing over portions of the interior Mid-Atlantic, particularly
over the central and southern Appalachian Mountains. WPC has issued a
30-50% probability of 0.1" of ice accretion over northwestern North
Carolina and into southwestern Virginia.

A strong storm system is currently pushing southward through northern and
central California today. Despite being a strong system, the track of this
deepening mid to upper level closed low will not be conducive to
significant precipitation across California over the next few days.
Moisture values will remain at or below seasonal averages.  Subsequently,
only light to locally moderate precipitation amounts in the .10-.25"+
range expected across northern to central California over the next two
days. This system will settle into the Southwest United States, with more
significant impacts expected in the medium range over the southern and
central Plains.

Genz

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