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000
FXUS62 KRAH 171752
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
155 PM EDT Wed Apr 17 2024

.SYNOPSIS...
A warm and moist southwest flow will persist today. A weak front
will move east across the region tonight, then a stronger cold front
will cross the area late Friday into Saturday, before stalling out
just to our south.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 810 AM Wednesday...

* Two chances of rain, mainly spotty and patchy light rain this
  morning toward midday across the mainly the western Piedmont with
  some scattered showers and possibly a storm later this afternoon
  and especially this evening.

The latest surface analysis shows a warm front extending from
southwestern VA southeast across the Triangle region into eastern
NC. North of the front surface dew points are mainly in the 40s
while south of the front dew points are in the upper 50s to even the
lower 60s. Further aloft, short wave ridging is noted across
the Carolinas into the mid-Atlantic with a couple of mid/upper
level disturbances noted at the nose an eastward advancing
speed max across the eastern TN Valley. The thunderstorms that
developed across the Sandhills on Tuesday evening dissipated
several hours ago and skies are partly cloudy with mainly high
clouds.

The warm front will lift north into VA this morning. At the same
time the mid/upper level disturbance across the TN Valley will shift
east and move across the Carolinas and VA this morning and early
afternoon. This feature is producing some spotty rain/showers early
this morning across eastern TN, far northern GA and far southwest
NC. This light precipitation may spread into the western Piedmont
and Triad areas between 8am and noon. The precipitation should
diminish as it moves east but a little spotty rain may reach
the Triangle area toward midday with mainly dry conditions
elsewhere through the early afternoon. A second threat of rain
is associated with a weakening cold front that will begin to
move east across NC late tonight. This feature may produce some
isolated showers across the western Piedmont late this afternoon
with scattered showers and possibly a thunderstorm expected
across the eastern Piedmont, Triangle, Sandhills and Coastal
Plain late this afternoon and especially this evening. Coverage
should be limited and storms are not expected to be strong.
Otherwise, expect thickening high clouds today with mostly
cloudy skies are expected this afternoon and evening. Skies
will clear from the northwest late tonight. Highs today will
mainly range in the lower 80s with temperatures a little cooler
near the VA border with some mid 80s possibly near the SC
border. Lows tonight will mainly range in the lower 60s.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
As of 300 AM Wednesday...

* Warm with highs 10 to 15 degrees above average.

A weakening cold front will move across the eastern Carolinas
on Thursday morning and off the coast during the afternoon. A
northwest flow aloft will develop on Thursday with the flow
becoming more westerly on Thursday night. This flow will result
in drier air moving into the region with PW values dropping
below an inch with surface dewpoints ranging in the upper 40s to
lower 50s. Lingering clouds on Thursday morning will give way
to mainly clear skies and fair weather that should continue
into Thursday night. Highs on Thursday will mainly range in the
mid to upper 80s with some lower 80s near the VA border. These
highs are about 10 to 15 degrees above average. Mild low
temperatures Thursday night will range in the mid 50s to around
60.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 317 AM Wednesday...

Upper pattern through the extended:  A series of short-wave
perturbations will periodically pass over central NC Friday through
Sunday, followed by a potentially more vigorous short-wave Monday
into Tuesday morning. Nwly flow aloft will return on Tuesday.

Friday and Saturday: Flow aloft will generally remain wly Friday and
Saturday. However, ensembles are hinting at a few passing short-
waves moving over our area in this time period. These features in
conjunction with a sfc cold front could trigger scattered showers
and thunderstorms both Friday and Saturday afternoon/evenings.
Forcing for ascent does like pretty muted as guidance maximizes mid-
level height falls well to our north. This may limit coverage both
afternoons, but scattered showers and storms appear plausible
(chances look best Friday afternoon/evening; Saturday has trended a
bit drier and cooler).

Sunday through Tuesday: Flow aloft turns a bit more swly Sunday and
Monday increasing low-level moisture advection into the southeast.
Guidance has come into a bit better agreement pinning the sfc cold
front and any instability to our south. This scenario would limit
thunderstorm chances in this period, and generally suggests that the
higher QPE could be to our south.  Continue to trend POPs highest
across our southeast Sunday afternoon/evening to reflect this signal
in the guidance.  Deterministic models depict a few waves of low
pressure riding along the front Sunday into Monday. If these
features move a bit further inland, some thunder may be possible
across the southern Coastal Plain.  Overall though expecting
primarily stratiform rain in this period. Any lingering rain should
push east of the area by Tuesday

Temperatures Saturday through Tuesday suggest a cooling trend with
highs in the mid to upper 70s Saturday followed by highs in the mid
to upper 60s Sunday/Monday. Temps will rebound into the mid 70s
Tuesday.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
As of 155 PM Wednesday...

VFR conditions are likely across central NC for the next 24 hours,
although two windows of light rain may produce a brief dip in vsbys
to high-end MVFR. The first of these is an area of very light rain,
falling from mid level clouds, over eastern sections currently, and
this will affect RDU/RWI/FAY prior to 20z. Another round of light
showers is expected to cross central NC west to east between 21z and
03z, associated with a weak mid level disturbance passing by, ahead
of a weak surface front. These showers, too, will be falling from
higher-based VFR clouds, so any drop to MVFR vsbys late this
afternoon through evening will be very short. Otherwise, VFR clouds
will persist through much of tonight, with skies mostly clearing out
(to just high thin clouds) west to east late tonight through mid Thu
morning, after the weak cold front moves through and the disturbance
aloft exits to the east. Surface winds will be from the SW, 8-15 kts
with 15-20 kt gusts this afternoon, decreasing to under 10 kts
tonight, then shifting to be from the W or WNW late tonight through
Thu morning.

Looking beyond 18z Thu, VFR conditions are expected to dominate
through early Fri afternoon, although a period of sub-VFR cigs is
expected 09z-13z Fri morning in the northeast (mainly RWI, perhaps
reaching RDU). We`ll have a good chance of showers/storms late Fri
through Sat morning, with a risk of sub-VFR cigs/vsbys in fog Fri
night. Rain chances and the potential for sub-VFR conditions will
linger Sun into Mon as the front settles just to our S and cooler
high pressure builds in from the N, but uncertainty is high during
this time frame. -GIH

&&

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

&&

$$
SYNOPSIS...Hartfield
NEAR TERM...Blaes
SHORT TERM...Blaes
LONG TERM...Luchetti
AVIATION...Hartfield