-- Discussion containing changed information from previous version are highlighted. --
368
FXUS62 KRAH 011916
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
315 PM EDT Wed May 1 2024

.SYNOPSIS...
Weak high pressure will build over the Carolinas and Southeast this
evening through Friday, resulting in very warm temperatures. A
series of weak upper level disturbances will move through the region
Friday evening through Sunday, bringing periods of unsettled
weather.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 230 PM Wednesday...

A compact shortwave has shifted off the NC coast as of 17z
mesoanalysis data with shortwave ridging and subsidence inversion
building behind in its wake. At the surface, a pressure trough and
moisture axis continues to slowly sag through central NC and
currently stretches from north of Elizabeth City, southeast of
Raleigh, and through Mackall Army Airfield near Scotland County. Dew
points across central NC have been sufficient to produce widespread
afternoon cumulus clouds, but the rich moisture east of the pressure
trough characterized by dew points in the low/mid 60s, is where 500-
1000 J/kg of MLCAPE and isolated showers have begun to develop.

The most persistent cluster is located in the vicinity of
Fayetteville and have so far struggled to gain sufficient depth/size
to produce much lightning given the abundant dry air aloft.
According to SPC Mesoanalysis, better 700mb moisture exists on the
backside of the departing shortwave and +1000 J/kg of MLCAPE in
eastern NC has resulted in more efficient updrafts and showers to
deepen into storms. This storms and the outflows they produce may be
what is required to see scattered showers and isolated storms to
develop in the vicinity of the I-95 corridor through the
afternoon/evening. Effective shear of 15-20 kts would result in
mostly pulse storm mode and clusters developing along common cold
pools. Sub-severe winds and cloud to ground lightning would be the
primary hazards if any storms are able to sustain themselves into
our forecast area.

Shallow moisture advection tonight behind a seabreeze into the
Coastal Plain and Sandhills may result in patchy fog development
with clear skies and calm surface conditions. Moisture depth will be
a limiting factor for seeing areas of fog and would rely heavily on
strong radiational cooling to cool the surface below the upstream
crossover temperature. Lows tonight will range mid 50s to low 60s.
Low 50s will be possible in the typical cool spots.

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
As of 220 PM Wednesday...

The weather should remain quiet on Thursday with a weak surface high
over the region. A weak upper level ridge should also build across
the Carolinas, limiting overall sky cover. The primary exception to
that should be the development of a sea breeze along the coastline,
which should push some scattered diurnal cumulus clouds across
southeastern counties during the afternoon. In addition, some high
clouds should begin to move in from the west late Thursday night.
Mid to upper 80s are forecast for Thursday, with an isolated 90
degree reading possible. Rising heights should also allow for warmer
overnight lows, generally in the low to mid 60s.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
As of 315 PM Wednesday...

Strong upper level ridge will influence the region Friday before
moving offshore early Saturday. A series of shortwaves will move
across the region early next week. At the surface, high pressure
will influence the Mid-Atlantic region. Light calm winds with mostly
sunny skies will set up for warm day Friday with highs well above
average in the mid to upper 80s both days. By Saturday morning
confidence in the forecast becomes better than it has in the past
few days. Latest data shows by Saturday morning increased moisture
values of 1.5+ ahead of a cold front moving across the TN and OH
valley. As the front moves into the region it will bring isolated to
scattered showers and storms to the area Saturday and again Sunday.
The cold front will move across the region Sunday before stalling
across the region on Monday. Less coverage is expected on Monday but
depending where the front stalls, isolated to scattered showers and
storms could be possible especially in the afternoon with daytime
heating. The stalled front is expected to dissipate and most of
Tuesday is expected to be dry, but multiple long range models show
another round of showers and storms developing by late afternoon
Tuesday ahead of another frontal passage moving across the Southern
Plains and Southeast.

Temperatures over the weekend will largely depend on timing and
coverage of the precipitation, but generally expect highs in the
upper 70s to low/mid 80s. Lows in the upper 50s and low 60s.
Temperatures are expected to increase through the week with highs 10
to 15 degrees above average by Wednesday. Most of the region will
see upper 80s to low 90s by Wednesday.
-- End Changed Discussion --

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
As of 120 PM Wednesday...

An area of agitated cumulus in the vicinity of FAY has been
producing brief showers that redevelop along a prior showers outflow
for the past hour. So far, the dry air aloft has prevented enough
hydrometeors at or above -10C and have been void of lightning so far
this afternoon. Regional satellite has shown some glaciation on the
tops of a couple updrafts, so isolated lightning can not be ruled
out through the afternoon. Cumulus clouds in the vicinity of RWI
have remained flat and shallow which has prompted the removal of the
tempo in favor of a period of VCSH. Shallow moisture advection
behind the seabreeze may result in patchy fog affecting the Coastal
Plain (FAY/RWI) with less confidence on impacts at RDU. Fog/stratus
will quickly clear after daybreak with light winds generally out of
the southeast through the afternoon with scattered fair weather
cumulus.

Looking beyond 18z Thu, VFR conditions will prevail through Fri. The
chance for sub-VFR conditions within scattered to numerous showers
and storms will increase starting Fri night, lasting through Sun, as
a series of disturbances passes over the region. Areas of early-
morning fog are also expected. -GIH

&&

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

&&

$$

SYNOPSIS...Hartfield
NEAR TERM...Swiggett
SHORT TERM...Green
LONG TERM...CA
AVIATION...Swiggett/Hartfield