750
FXUS62 KRAH 030627
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
227 AM EDT Wed Jul 3 2024

.SYNOPSIS...
Canadian high pressure centered just offshore the Middle Atlantic
coast will linger over the Carolinas through tonight. A subtropical
ridge will otherwise extend across the South Atlantic states through
the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 920 PM Tuesday..

Forecast is in good shape with very few changes needed. Surface high
pressure centered near NYC at this hour will continue to extend down
through our area while drifting slowly eastward. Minor mid level
perturbations are seen in layer WV imagery moving SE over our
region, but with a very dry column (00z GSO PW near the 10th
percentile) and stable mid levels, little more than a few mid clouds
will be observed through tonight. Still expect lows tonight in the
upper 50s to lower 60s. -GIH

Earlier discussion from 145 PM: As surface high pressure currently
centered over the Northeast continues to slowly slide offshore this
afternoon, quiet weather will continue across Central NC. Dew points
today have been in the 50s across the region, with onshore moisture
moving in later this evening dew points will get into the 60s later
tonight especially in the eastern portions of the Piedmont and
Coastal Plain region. High temperatures will top out this afternoon
in the mid 80s with a few areas in the south getting into the upper
80s. Lows overnight will be slightly warmer than last night ranging
from low to mid 60s.

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
As of 230 PM Tuesday..

Continued dry on Wednesday under the influence of a 1024mb high off
the Mid-Atlantic coast and and eastward shifting 595dm sub-tropical
at 500mb over the Deep South.  As the surface high shifts eastward
as well, return flow will begin to kick in, but likely not until
late in the day, delaying the return of upper 60s and lower 70
dewpoints until Thursday.  1000-850mb thicknesses rise 15-20m over
today`s expected values, which will result in highs in the upper
80s and lower 90s, coolest in the northeast away from the thermal.
ridge.

With southerly return flow becoming established Wednesday night,
guidance suggests some stratocu across the foothills and drifting
into the western Piedmont, with otherwise quiet weather and lows
likely to range from the upper 50s east to lower 60s west.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 225 AM Wednesday...

Aloft, a potent northern stream s/w will move through the Great
Lakes Fri/Fri night, as the longwave trough amplifies southward
through the Plains and MS Valley. As the trough amplifies, the high
over the Southeast US will be gradually pushed southeastward off the
Southeast US coast Fri night/Sat. Another northern stream s/w will
drop into the northern Plains and track eastward along the US/Canada
border Sat/Sat night as the initial s/w lifts newd into Canada. As
this second s/w moves through the Great Lakes Sun/Sun night, another
disturbance will quickly drop ssewd through the northern Rockies and
into the central Plains, helping further amplify the longwave trough
through the southern Plains/lower MS Valley by Mon morning. All the
while, central NC will remain situated between the trough to the
west and the high to the east, with deep southwesterly flow
prevailing. The fly in the ointment is the medium-range guidance
picking up on a possible tropical low approaching the Carolina coast
over the weekend. There is some uncertainty wrt this feature for Mon
and Tue. Also on Sun/Sun night, Beryl is expected to make landfall
along the western Gulf Coast, however exactly where that happens and
when will determine what happens to the system as/where it moves
inland early next week. There is still a lot of uncertainty in the
forecast for Mon/Tue, but for now, it appears the longwave trough
axis will generally remain west of the Appalachians through Tue,
while s/w disturbances move through it. At the surface, a lee trough
will remain in place through Sat, when a cold front will approach
from the west. As of the latest model solutions, the front still
appears to get hung up and generally wash out along the Appalachians
Sat night, as Bermuda high pressure ridges westward. An area of low
pressure will sit off the Southeast US coast Fri/Fri night, then
weaken on Sat before the remnants of the low lift newd off the
Carolina coast Sat night/Sun. possibly laying W-E through WV/VA Sun
as high pressure lifts newd through the OH Valley and Northeast, but
the front appears to stay north of central NC. Expect swly flow and
the advection of warm, moist air into the area to take over once the
ridge moves out Thu morning and prevail through at least Sat. The
lee trough should once again strengthen over the area early next
week.

Temperatures will be above to well above normal through Tue. Latest
forecast heat index values of 100-106 are expected across much of
central NC for Fri and Sat. Sun and Mon heat index values max out
around 100, mainly across the south, but may creep upward again on
Tue.

As for rainfall, the weather seems to be turning a bit wetter. As
the mid-level ridge gradually gets suppressed south and the lee
trough strengthens, expect more diurnally driven convection Fri
through Tue, with higher chances/amounts as s/w disturbances clip
the area.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
As of 210 AM Wednesday...

The presence and influence of Canadian high pressure that will
extend from just offshore the Middle Atlantic coast southwestward
into the Carolinas will favor mostly VFR conditions in cntl NC
through Thursday morning. While a brief period of visibility
restrictions cannot be entirely ruled out at RWI around daybreak,
the likelihood seems relatively low given the foregoing
Canadian/continental air that would favor more dew than fog, should
surface temperatures even radiationally cool sufficiently amid areas
of ~ 6 thousand ft AGL stratocumulus that are apt to persist there.

Outlook: A chance of showers/storms will exist over the wrn NC
Piedmont (INT/GSO) Thu afternoon-evening and throughout cntl NC Fri
through the weekend.

&&

.CLIMATE...
Record High Temperatures:

July 4:
KGSO: 98/1970
KRDU: 101/2012
KFAY: 98/2019

July 5:
KGSO: 98/2012
KRDU: 102/1999
KFAY: 101/2002

July 6:
KRDU: 102/2022
KFAY: 99/1990


Record High Minimum Temperatures:

July 4:
KGSO: 73/2018

July 5:
KGSO: 74/1999
KRDU: 78/1902
KFAY: 77/2005

July 6:
KGSO: 76/1999
KRDU: 79/1900
KFAY: 76/2017

July 7:
KGSO: 73/2019
KRDU: 77/1900
KFAY: 78/2017

&&

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

&&

$$
SYNOPSIS...MWS
NEAR TERM...Hartfield/CA
SHORT TERM...BLS
LONG TERM...KC
AVIATION...MWS
CLIMATE...RAH