-- Discussion containing changed information from previous version are highlighted. --
690
FXUS62 KRAH 130122
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
922 PM EDT Wed Jun 12 2024

.SYNOPSIS...
-- Changed Discussion --
Surface high pressure over the northern mid-Atlantic will drift east
and move off the mid-Atlantic coast by Thursday morning. An area of
low pressure will move off the east coast of Florida Thursday
morning, then lift northward off the Southeast and mid-Atlantic
coasts through late Friday. A cold front will then slide southward
into the area Friday night and Saturday.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 910 PM Wednesday...

No major changes to the previous forecast with this evening update.
The 00Z upper air analyses show one week s/w over the mid-Atlantic
coast and another over the Deep South/TN Valley. The 00Z surface
analysis shows high pressure off the mid-Atlantic coast and over the
WV/western PA, with a weak trough between extending from the
Southeast US to the Northeast US along and just east of the
Appalachians. While the weather should remain dry tonight, as the
s/w to the west progresses eastward toward/into central NC tonight,
expect continued broken/overcast high clouds to persist. The
continued southeasterly return flow at the surface will keep
dewpoint temperatures in the mid 60s across much of the area, making
for a humid night as lows tonight should also be in the low to mid
60s.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
As of 230 PM Wednesday...

...This week`s heat and humidity will peak Friday...

A shortwave over the lower Tennessee Valley today will cross the
area late tonight and move offshore on Thursday while interacting
with a disturbance that the NHC is monitoring over Florida, likely
producing an area of low pressure well off the Carolina coast. That
low is not expected to develop into a tropical system at this time,
and is expected to continue to move off to the east-northeast on
Thursday, shunting the associated moisture well offshore as well.
This will leave Central North Carolina between that area of low
pressure to the east and a cold front moving through the Midwest
with a ridge of high-pressure extending southwestward from off the
mid Atlantic coast across NC.

Cirrus  associated with the upper level shortwave tonight should
gradually clear from west to east on Thursday and result in quite a
bit of sunshine again. East-northeasterly flow between the
aforementioned surface low and high-pressure should be a little
enhanced over coastal areas, but it appears interior NC wont feel
much influence and instead see a 5m increase in low level
thicknesses and modest mixing. resulting in temperatures 2 to 3
degrees warmer on Thursday  and more lower 90s in the southeast CWA.
Guidance also suggests enough mixing to keep dewpoints in the lower
60s or even some upper 50s, helping to hold back the higher heat
indices for another day.  Lows Thursday night will be in the low to
mid 60s.

Friday continues to look like the hottest day ahead of the
approaching cold front with the development of a sharp thermally
enhanced lee trough but very little deep moisture to support much
convection. If it does develop, the northern portions of the
Piedmont appear favored given initiation in the northern Foothills
into SW VA and the upper trough cross the Mid-Atlantic States.
However the relative warmth aloft looks to limit instability to less
than 1000 MLCAPE. The more recent runs of the GFS are notably more
active in the evening across the northern Piedmont in northern
coastal plain as the frontal convergence shifts through the area. It
is hard to imagine no shower at all, but we will maintain a dry
forecast overall given less favorable initial instability and diurnal
timing.  Models indicate low level thicknesses climbing by 10m over
Thursday and highs reaching to mid 90s, pushing heat indices into
the mid and upper 90s. Lows Friday night will be muggier with the
delayed timing of the front, with upper 60s and lower 70s forecast.


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 251 PM Wednesday...

After nwly flow and dry conditions Saturday, anomalous mid-level
ridging anchors over the US Sunday through Monday, amplifying into
the northeast through mid-week. This will generally encourage warmer
than average temperatures and drier conditions. However, diurnal
showers/isolated storms (most likely originating over the mountains
and trickling into the lower terrain) will be possible mostly in the
west each afternoon.

As far as temperatures, ensemble probabilities for greater than 90
degrees peak across the NC/SC border both Saturday and Sunday. Thus,
it`ll still be hot each day this weekend, reaching the upper
80s/lower 90s (across the south). Under the influence of the
anomalous ridge aloft, the warming trend should continue through
Wednesday with highs likely reaching the upper 80s to lower 90s
again each afternoon. Ensembles are in pretty good agreement mixing
dew points out into the lower to mid 60s each day, and thus heat
indices generally maximize in the mid to upper 90s each afternoon.
Regardless, given the successive days of above normal temperatures,
those who are spending significant time outdoors should practice heat
safety by hydrating frequently and take breaks in shady areas if
possible.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
As of 735 PM Wednesday...

Multi-layered cloudiness will continue to stream across central NC
through tonight as a weak disturbance passes to our south. Crossover
temperatures around 63 degrees near RWI will likely be approached by
sunrise, but not exceeded, and may produce a short lived period of
MVFR vsby. Warmer temps this afternoon and mostly broken cloud cover
overnight should prevent any prolonged fog, but confidence was not
high enough to remove from TAF at this time. Light winds from S
(GSO/INT) to E (FAY/RWI) are expected Wed afternoon with diurnal
cumulus bubbling by early afternoon.

Outlook: Generally dry, VFR conditions are expected through early
next week. Some patchy late night/early morning fog or stratus is
possible into the first part of the weekend. -Blaes

&&

.CLIMATE...

Record High Temperatures:

June 14:
KGSO: 98/1926
KRDU: 97/1944
KFAY: 100/2022

&&

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

&&

$$

SYNOPSIS...KC
NEAR TERM...KC
SHORT TERM...BLS
LONG TERM...Luchetti
AVIATION...Swiggett/Blaes
CLIMATE...RAH