684
FXUS62 KRAH 121853
AFDRAH

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

.SYNOPSIS...
Surface high pressure over the eastern Ohio River Valley will drift
east and move off the mid-Atlantic coast by Thursday morning. A hot
and humid air mass will develop over the region on Thursday and
especially Friday. A cold front will move across the area late
Friday and early Saturday bringing some cooler temperatures for the
weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 200 PM Wednesday...

Mid-level cumulus clouds are rather widespread across the forecast
area this afternoon, and it appears a good amount of those clouds
will persist into the evening. Later in the evening, a lack of
mixing should bring an end to the mid level clouds, although some
high cloud cover is expected to persist overnight. The forecast
remains dry. Overnight lows will come up a few degrees from last
night, with all locations in the 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 /17Z WEDNESDAY THROUGH MONDAY/...
As of 100 PM Wednesday...

An extensive stratocumulus field will result in some 3.5-5kft
ceilings through the afternoon and early evening. Otherwise,
scattered to occasionally broken cirrus clouds will continue to
stream across the area during the forecast period. Persistence and
ensemble guidance suggests patchy fog will be possible again early
Thursday morning. Winds will remain light and generally from the S-
SE.

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...Blaes
NEAR TERM...Green
SHORT TERM...BLS
LONG TERM...Luchetti
AVIATION...CBL/Blaes
CLIMATE...RAH