542
FXUS62 KRAH 121353
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
950 AM 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 950 AM Wednesday...

Minimal changes needed with the update this morning. There is a
small area of low clouds that are currently moving through the
central portion of the forecast area, with clouds as low as 900 feet
at Siler City, 1500 feet at Sanford, and 2200 feet at RDU. This
should move through the area quickly, with higher clouds expected
through the rest of the day. Previous discussion follows.

As of 255 AM Wednesday...

The latest surface analysis shows surface high pressure centered
over PA and NY early this morning with a light north to
northeasterly flow across central NC. The airmass across central NC
is rather dry with PW values of around an inch which is about 60-70%
of normal. Further aloft, a northwest flow at mid levels will weaken
and become more westerly and even southwesterly today and
tonight as a short wave trough moves into the Deep South. It
should remain dry today with a mix of clouds and sunshine.
Expect patches of cirrus clouds to move across the region along
with some afternoon stratocumulus clouds, especially across the
western Piedmont where low level moisture is a bit more
prominent. The airmass moderates just touch today across the
south but more noticeable warming should be noticed across the
north and northwest including the Triad where low level
thickness values warm a good 8 to 12m. This will result in highs
similar to Tuesday or maybe a degree or so warmer across the
southern/southeastern areas with highs about 3 to 4 degrees
warmer across the north. Highs should range in the mid 80s in
the VA border counties and Triad area with highs of 85 to 90
elsewhere including the Triangle and Fayetteville areas. Lows
tonight will be a little milder and a touch muggier with lows
mainly in the mid 60s. -Blaes


&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
As of 320 AM Wednesday...

A stationary frontal zone extending from northern FL and far southern
GA to off the Carolina coast will linger through Thursday night.
Several weak areas of low pressure that have developed in part by
convective clusters near and along the front will persist and
advance northeast and will be supported by an approaching short wave
trough. Guidance has perked up a bit with this system suggesting
some sort of low pressure area may develop late Thursday night
or into Friday as the system moves away from the eastern
Carolinas. At the same time, surface high pressure across the
mid-Atlantic will shift east and off the coast by Thursday. The
air mass across much of central NC warms on Thursday as low
level moisture values increase, making it feel warmer and more
humid. Will keep a dry forecast in place with central NC in
between the frontal zone and surface low off the Carolina coast
and an approaching cold front in the Great Lakes and western OH
Valley. Highs on Thursday will be warm, ranging in the upper 80s
to around 90 with some lower 90s across the Sandhills and
southern areas. These highs are about 2 to 6 degrees above
average. Lows on Thursday night will range in the mid 60s which
is a few degrees above average. -Blaes
&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 330 AM Wednesday...

A mostly dry extended period is expected with a roller coaster of
temperatures from hot on Friday to near normal over the weekend
before warming back up early next week.

A low pressure system that the NHC gives a marginal (20%) chance of
tropical development will be centered offshore of the coast of the
Carolinas on Friday, as it continues to move NE in the western
Atlantic. It is expected to be far enough east that no impacts to
central NC are expected. Friday still looks to be the hottest day of
the period and likely of the year so far, with highs in the lower-to-
mid-90s and lows in the upper-60s to lower-70s. Heat indices in the
mid-to-upper-90s are expected from the Triangle south and east,
which could put sensitive individuals at risk. Be sure to take
precautions which include limiting amount of time spent outdoors
during the hottest part of the day (if possible), and drinking
plenty of water.

Meanwhile a northern stream shortwave will swing from the Great
Lakes into the Northeast US on Friday and Friday night. This system
will drag a cold front that moves SSE and crosses central NC on
Friday night into Saturday morning. However, with the trough passing
so far to our north and a strong ridge building into the Deep South,
the front will be devoid of any upper forcing. This combined with
the poor diurnal timing mean the frontal passage should be dry. If
the progression of the front is slow enough, a small minority of
GFS/ECMWF/Canadian ensemble members indicate a shower or storm can`t
be ruled out in the extreme SE (mainly Sampson County) on Saturday
afternoon or evening, so continue slight chance POPs there. But
overall the forecast is trending drier. As for temperatures, cooler
and drier air will arrive behind the cold front as high pressure
extends down from Southeast Canada and the Northeast US. This will
provide some relief from the heat and humidity this weekend.
Forecast highs both Saturday and Sunday are upper-80s to lower-90s,
with lows generally in the 60s. This is still slightly above normal,
but dew points will likely only be in the mid-50s to lower-60s.

High pressure will move off the northern Mid-Atlantic coast from
Sunday into early next week, shifting the low-level flow to a SE
direction. This will bring increased clouds, particularly in the
west. Do carry slight chance POPs in the far western Piedmont on
Sunday and far northwestern Piedmont on Monday and Tuesday, where an
isolated shower or storm can`t be ruled out in the upslope flow
regime. However, with the anomalous mid/upper ridge overhead,
coverage should be limited at best. Farther east, dry air and
subsidence should preclude any convective development. The ridge
will also help temperatures increase once again, with forecast highs
in the lower-90s on Monday and lower-to-mid-90s on Tuesday.

&&

.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
As of 625 AM Wednesday...

VFR conditions are generally expected to continue across central NC
for the 24 hour TAF period as a westerly flow aloft and surface high
pressure moves across the region. There are a few patches of MVFR
fog in a few spots this morning, mainly in the central Coastal Plain
and Sandhills. There is also a limited threat of some patchy low
stratus early Thursday morning across southern and eastern areas but
confidence in this is rather limited. Otherwise, patches of cirrus
clouds will mix with areas of VFR stratocumulus with CIGS of 5-8kft
later this morning and this afternoon. Light mainly northeasterly
winds early today will become southeasterly at 5 to 10 kts later
this morning and afternoon with a light southerly wind tonight.

Outlook: Generally fair weather is expected through the rest of the
work week into the weekend. Some patchy late night/early morning fog
or stratus is possible into the first part of the weekend. -Blaes

&&

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

&&

$$

SYNOPSIS...Blaes
NEAR TERM...Green/Blaes
SHORT TERM...Blaes
LONG TERM...Danco
AVIATION...Blaes