-- Discussion containing changed information from previous version are highlighted. --
584
FXUS62 KRAH 110617
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
217 AM EDT Sat May 11 2024

.SYNOPSIS...
A cold front will move off the coast of the Carolinas this evening.
High pressure will follow and extend across the Southeast and Middle
Atlantic through the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 845 PM EDT Friday...

Surface cold front has pushed through our area and expected to exit
the coast over the next few hours. The severe thunderstorm watch has
been canceled for the areas. No more storms are expected tonight.
Although there is one storm exiting the southern tip of Sampson
county, but not expected to become severe. Dew points across the
much of the region have dropped into the mid 40s to mid 50s, with
temperatures in the mid 60s NW to low 70s SE. Gusty winds behind the
front are expected to diminish over the next few hours, but  light
northerly winds of 5 to 10 mph will continue through the night. Lows
overnight will range from low 50s NW to mid 50s SE.

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
As of 1225 PM Friday...

Shortwave ridging will give way to a shortwave digging southeastward
into the Great Lakes, OH valley and northern Mid-Atlantic. While
most of the energy with the trough will remain to our north in VA,
height falls will promote some weak lift in the mid to late evening
hours across our northern counties. At the surface, high pressure
will give way to a lee trough. A secondary cold front or surface
trough will then move through in the evening and overnight hours.
Highs will be some 5-9 degrees below normal in the low to mid 70s,
comfortable for early May. WAA in a return SW flow aloft Sat night
between 850-700 mb will aid some weak (~100 J/kg) instability in the
mid to late evening hours ahead of the trough passage. While most
areas will see more dry time than showers, we introduced a slight
chance of isolated showers across mainly the northeast Piedmont and
northern Coastal Plain, roughly along/north of a line from Raleigh
to Rocky Mount. Any showers will exit by late evening, with lows
dipping a few degrees below seasonal normals into the upper 40s to
mid 50s.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
As of 115 PM Friday...

A period of dry weather and clear skies Sun into early Mon as a
broad shortwave trough will be pivoting across the Northeast and Mid-
Atlantic Sun morning and slide towards the Northeast coast by Sun
evening. Strongly convergent flow aloft will favor strong subsidence
on the backside of the departing trough and transient high pressure
over the area before shifting offshore by Mon morning. Mostly clear
skies and calm conditions will support steep surface inversions and
pockets of radiational cooling and have trended down minimum
temperatures, especially in the typical cool spots (mid 40s to low
50s).

The next chance for rain will be right around the corner as the flat
shortwave ridging and 850 anti-cyclone over the Southeast shift
offshore Mon evening into Tues. A surge in deep southwesterly flow
off the Gulf driven by a closed low spinning through the Mid-MS
Valley will spread anomalous moisture (PWAT 1.3 to 1.6, 90th
percentile) and waves of 700 to 850mb WAA through the southern Mid-
Atlantic. Deep layer moisture appears to be maximized over the area
on Tues, best chance for periods of showers/storms, while Wed may be
a bit more uncertain. A tongue of dry air from 700mb and up will
round the southern side of the shortwave and overspread portions of
the Southeast and southern Mid-Atlantic. Where this dry pocket sets
up will depend on the track of the aforementioned shortwave, which
there area still timing differences on its departure Wed into Thurs.
Nevertheless, will continue to highlight chance to likely PoPs
during this time given the potentially favorable track and
associated synoptic forcing and increased instability, but coverage
may be more limited during this time. Temperatures will be coolest
on Tues (5 to 10 degrees below normal), otherwise highs/lows will be
near to slightly above normal through the remainder of the extended.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
As of 215 AM Saturday...

VFR conditions will prevail across central NC through Saturday
afternoon, with the one exception of some lingering stratocumulus
over the far east (including RWI) which has resulted in periods of
MVFR ceilings. While RWI is back to VFR, some high-res guidance
(including the RAP and GLAMP) shows MVFR returning there later
tonight, so have a TEMPO group at RWI for that potential from 08z-
12z. A deck of clouds from about 6-10 kft will move across central
NC from NW to SE on Saturday evening, and they may be accompanied by
a band of showers. Confidence in any brief sub-VFR visibilities with
the showers is low, but it cannot be entirely ruled out. Northerly
winds tonight will become more westerly/southwesterly by tomorrow
afternoon and evening, remaining less than 10 kts sustained and
possibly gusting up to 15 kts at times during the day.

Outlook: Rain and IFR-MVFR restrictions, lowest over the Piedmont at
INT/GSO, will overspread cntl NC Tue morning, with a following
chances of showers/storms Tue afternoon through Wed.
-- End Changed Discussion --

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...MWS
NEAR TERM...CA
SHORT TERM...Kren
LONG TERM...Swiggett
AVIATION...Danco/MWS