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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KRAH 222315
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
715 PM EDT Mon Apr 22 2024

.SYNOPSIS...
-- Changed Discussion --
High pressure will build overhead tonight through Tuesday, then
shift to our southeast. The resulting southwest flow will bring
warming temperatures through mid to late week.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TUESDAY/...
As of 700 PM Monday...

Quick update... We have issued a Frost Advisory for all of the
CWA except for Guilford and Forsyth Counties tonight based on
latest MET and MEX statistical guidance, which tend to be
favored in strong radiational cooling scenarios. This morning`s
1000-850mb thickness was 1316m at GSO which would also lean
toward more mid 30s with no airmass moderation. -BLS

A quiet but cool night ahead. The mid level shortwave trough over E
NC continues to push eastward, yielding the onset of deep layer
subsidence and drying. The remaining stratocu over the S and E
sections will slowly diminish as this drier air works in with
stabilization as we reach and pass sunset, resulting in a clear
night with calming winds as the surface high settles overhead. As
lower dewpoints in the 20s to lower 30s pour into the area from the
N, this combined with excellent radiational cooling conditions will
bring about a risk for isolated frost patches, primarily over the
rural areas of the far N Piedmont for an hour or two before sunrise.
Currently, it appears that any frost will be too isolated in nature
and briefly to result in any hazardous conditions or damage to
vegetation, so after collaboration with surrounding offices, will
not issue a frost advisory at this time. Expect lows of 36-42. -GIH

&&

.SHORT TERM /TUESDAY NIGHT/...
As of 235 PM Monday...

Central NC will be under the influence of shortwave ridging on
Tuesday between a closed mid/upper low moving NE in the western
Atlantic and a northern stream shortwave diving down into the Upper
Great Lakes. So height rises and subsidence will keep us dry and
sunny. At the surface, ~1025 mb high pressure centered over GA and
the Carolinas on Tuesday morning will shift SE and offshore in the
afternoon. This will shift the low-level flow to a southwesterly
direction, helping bring 1000-850 mb thicknesses 20-30 m higher than
today, supporting warmer high temperatures mainly in the lower-70s.
This is still about 1-3 degrees below normal.

Lows on Tuesday night will be near normal in the SE and slightly
above normal in the NW, where mid and high clouds will be on the
increase in advance of the aforementioned northern stream shortwave
that will be moving into the OH Valley and Appalachians. This will
make for fairly uniform lows in the upper-40s to lower-50s.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
As of 241 PM Monday...

An upper level trough will swing across the Northeast Wednesday
morning followed by a weak shortwave swinging across the northern
Mid-Atlantic region Wednesday night. By Friday, upper level ridging
will take over through the weekend  resulting in fair weather for
the latter half of the long term period. At the surface, a low
pressure system centered over the southern portions of Quebec early
Wednesday morning will trail a cold front south along the
Appalachian Mountains. While showers will be persistent west and
north of the mountains latest model guidance is showing much of the
forcing loosing energy east of the mountain range thus limiting the
chance for rain across Central NC. Expect some passing sprinkles
Wednesday afternoon as the front moves across the region. As the
front moves offshore overnight, a cool dry high pressure will build
into the region with northeasterly winds taking over. If conditions
clear out early enough Thursday morning, light NE winds could help
result in some patchy fog across portions of the NE Piedmont and
Coastal Plain. Thursday and Friday are expected to be fair weather
days with mostly sunny skies and temps in the upper 60s north, to
low/mid 70s across the south. As high pressure and upper level
ridging strengthens across our region over the weekend and early
next week temperatures are expected to increase quickly with highs
in the mid/upper 70s Saturday, low to mid 80s Sunday, then by Monday
mid 80s across the entire region.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
As of 715 PM Monday...

24 hour TAF period: High confidence VFR conditions will prevail
through the TAF period. Expect clear skies and calm to light winds
overnight, with continued clear skies and winds increasing from NW
to SE through the afternoon Tuesday.

Outlook: Largely VFR conditions are expected through Sat. There are
two possible exceptions. First would be a small chance for a brief
period of light showers/sprinkles and/or borderline VFR/MVFR cigs as
a weak cold front moves into/through the area on Wednesday. The
other would be a possible brief period of borderline VFR/MVFR cigs
Thu morn/early aft. However, confidence in both occurrences of
restrictions remains low at this time.
-- End Changed Discussion --

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
Frost Advisory from 2 AM to 8 AM EDT Tuesday for NCZ007>011-
023>028-038>043-073>078-083>086-088-089.

&&

$$

SYNOPSIS...GIH
NEAR TERM...BLS/GIH
SHORT TERM...Danco
LONG TERM...CA
AVIATION...KC