195
FXUS62 KRAH 110635
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
235 AM EDT Thu Jul 11 2024

.SYNOPSIS...
A cold front will push slowly east across central North Carolina
tonight, reaching the Coastal Plain before stalling out early
Thursday morning. This front will push back westward into the
Piedmont Thursday, but will generally hold over the western and
central Carolinas through Sunday, as it slowly weakens.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 835 PM Wednesday...

Scattered showers and thunderstorms have been developing in the
past hour or so in the pre-frontal convergence zone out ahead of
the approaching cold front. The cold front, which is currently a
fine line on radar (no precipitation - wind shift to the NW)
will be merging with the convergence zone (where the SE winds
become SW). In addition, there is currently analyzed around 2500
j/kg of MLCape in the region around the Triangle to RWI to FAY.
Some of the hi-res models continue to suggest a fair amount of
thunderstorms around the eastern Triangle into the Coastal Plain
in the next couple of hours. There have been some gusty winds
with the showers/storms thus far and conditions are favorable
for 40+ mph wind gusts in the stronger storms. Otherwise, the
front will move into the Coastal Plain later tonight taking
these initial POP to the east and dissipating.

A decent gradient in overnight lows appears likely tonight,
with readings dipping into the upper 60s NW ranging into the
mid/upper 70s SE. Some patchy fog and stratus will be possible
across the south and east and mid 70s dew points still persist
there.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
As of 140 PM Wednesday...

Aloft, the longwave trough will remain over the MS Valley through
Thu night, while the strengthening Bermuda high slowly ridges
westward. Model guidance continues to show an area of low pressure
tracking wnwwd around the Bermuda high toward the mid-Atlantic coast
Thu/Thu night. At the surface, the surface boundary should retreat
westward through central NC Thu/Thu night. Meanwhile, a low could
develop along the front off the Southeast US coast Wed night, then
drift westward into the SC Thu/Thu night. There is still some
uncertainty wrt the timing and track of that system thereafter. As
the surface boundary retreats westward and the low aloft approaches,
cloud cover and chances for showers and storms will increase over
central NC from east to west through Thu night. Rainfall amounts
remain a bit uncertain, but still expect highest amounts over the
Coastal Plain, lowest over the western Piedmont. There is still a
marginal risk for excessive rainfall Thu/Thu night across most of
central NC. Highs should range from upper 80s east to mid 90s
southwest, but with the higher dewpoints accompanied by rain and
clouds, air temps should be decreasing as dewpoints are increasing.
As a result, heat index values should top out in the mid 90s Thu.
Lows should range from around 70 degrees north and west, to mid 70s
SE.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 235 AM Thursday...

Heights will rise on Sat as the broad troughing at mid-levels from
Fri shifts east mainly along the NC coast. West to southwest flow at
500 mb will ensue thanks to a weak trough axis stretching from the
Great Lakes into the Midwest. While this would normally reduce storm
chances, most model guidance shows that the low-level circulation
from Fri will be located roughly over eastern NC. While it will be
in a weakened state, a low-level convergence axis will still be
present, draped from NE to SW from roughly Roanoke Rapids to
Wadesboro. At the surface, there may be a weak surface low as well
along the Coastal Plain or along the coast. Forecast soundings show
relatively weak CIN and MLCAPE of 1200-1500 J/kg. This along with
the convergence axis and sea-breeze should favor another day of
scattered showers and storms. Chances would appear highest along and
SE of the convergence axis, roughly along/east of US-1. Coverage
should diminish after sunset with loss of heating. Highs should warm
into the upper 80s/90 in the east to low 90s W.

On Sunday, the flow at mid-levels roughly stays the same with
westerly flow. The low-level convergence axis is forecast to shift
offshore, with any surface boundary from Sat washed out by this
time. This along with lower PWATs should favor less overall chances
of storms. The best chance appears in the Sandhills to central
Coastal Plain as guidance shows a fairly robust sea-breeze
potential. Highs should warm with more sunshine and rising low-level
thicknesses to the low and mid 90s. Heat indices will also get close
to advisory criteria in the Triangle and Coastal Plain between 100
and 105.

Precipitation chances become more isolated in nature and more
diurnally driven Mon through Wed. Storms appear to be mainly focused
along the western Piedmont/Foothills along a persistent lee trough
setting up at the surface, as well as along the sea-breeze over the
southern Coastal Plain. Rain chances, however, look limited thus far
with forecast soundings showing a capping inversion. Downslope flow
and lowered PWATs may also limit coverage. The next best chance of
showers/storms may not come until late Wed or Thu as ensembles show
a potential cold front approaching. Outside of this, it will be hot
and humid, with highs in the mid to upper 90s to even some lower
100s over the Triangle. Lows will also be rather muggy and warm in
the mid/upper 70s, which could challenge some record high mins.
Dewpoints should mix out into the upper 60s W to low 70s E in the
afternoon under the westerly downslope flow, however heat indices
look to still be rather unbearable between 103 to 109 along/east of
US-1. The prolonged hot weather will increase the risk of heat-
related illnesses.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
As of 100 AM Thursday...

VFR conditions are expected to mostly dominate central NC
terminals through this evening, although a downturn to IFR is likely
starting later this evening, esp over central and eastern TAF sites.
A few showers in the E, just affecting RWI at this point, is all
that remains from the earlier band of storms this past evening,
along with sct-bkn MVFR clouds in the far NE and SE near RWI/FAY.
These lower clouds should clear out by 08z as a cold front pushes
past I-95 and brings drier air in from the W. A few showers and
isolated storms are possible in the far E this morning through this
afternoon, mainly E of RWI/FAY, with VFR conditions prevailing at
the TAF sites through early-mid evening. The front is then expected
to push back westward from mid evening through tonight, and an east-
to-west trend toward IFR cigs and scattered showers and storms is
expected starting around 02z-03z at RWI/FAY and around 03z-04z at
RDU, with INT/GSO holding at VFR with dry weather through the end of
the TAF valid period. Surface winds will be mainly from the N and NE
today, with a few gusts to 15-20 kts through early afternoon, then
shifting slowly east-to-west to be from the ENE or E from this
evening through tonight.

Looking beyond 06z Fri, sub-VFR conditions and numerous areas of
showers and isolated storms, including locally heavy rain, will
prevail early Fri morning through Fri night at all sites, as the
westward moving front slows then stalls over the W Piedmont or
Foothills, where it will linger into the weekend. Shower/storm
chances will persist, mainly each afternoon through evening and
primarily in the E Sat/Sun. Mon currently appears mostly dry with
only isolated storms. Morning sub-VFR fog and low clouds are
possible mainly E early Sat/Sun with fairly low chances Mon. -GIH

&&

.CLIMATE...
Record High Temperatures:

July 15:
KGSO: 97/1974
KRDU: 99/1997

July 16:
KGSO: 99/1915
KRDU: 101/1887
KFAY: 103/1937


Record High Minimum Temperatures:

July 11:
KGSO: 75/1992
KRDU: 77/1981
KFAY: 76/2019

July 12:
KGSO: 76/2011
KRDU: 78/2011
KFAY: 80/1935

July 13:
KGSO: 75/2017
KRDU: 78/2017
KFAY: 78/2017

July 14:
KGSO: 77/1981
KRDU: 77/2017
KFAY: 80/2017

July 15:
KGSO: 74/2019
KRDU: 76/1992
KFAY: 78/2015

July 16:
KGSO: 75/2010
KRDU: 77/2010
KFAY: 78/1992

&&

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

&&

$$

SYNOPSIS...Hartfield
NEAR TERM...Badgett/Luchetti
SHORT TERM...Hartfield
LONG TERM...Kren
AVIATION...Hartfield
CLIMATE...RAH