832
FXUS62 KRAH 041056
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
656 AM EDT Mon Aug 4 2025

.SYNOPSIS...
Canadian surface high pressure will extend across the Middle
Atlantic this week, while moist and perturbed southwesterly flow
aloft will focus across the TN and OH Valleys and Appalachians.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 325 AM Monday...

In the mid/upr-levels, swly flow will be directed across the
Southeast and srn Middle Atlantic, between a very slowly progressive
trough across the MS Valley and a ridge forecast to strengthen
across the wrn Atlantic. Within that swly flow regime, a low
amplitude shortwave impulse, and preceding plume of mid/high-level
cloudiness and virga/patchy sprinkles over ern NC, will move off the
srn Middle Atlantic coast this morning. It will be followed by at
least a couple of MCVs apparent in regional radar data over the lwr
Savannah Basin (near SAV) and the Oconee National Forest, which will
be directed nwd across SC today and probably across west-cntl NC
tonight. These features will also be accompanied by considerable
mid/high clouds and virga/patchy light rain.

At the surface, high pressure will continue to extend across the
Middle Atlantic, while a front will remain quasi-stationary over srn
GA. Unseasonably cool, and stable, nely to ely flow will prevail
across cntl NC.

The cool nely/ely flow regime will be kept cooler by generally
mostly cloudy conditions over the srn and nw Piedmont, where high
temperatures will be in the upr 70s to lwr 80s, ranging to partly
sunny and low-mid 80s elsewhere.

As the aforementioned MCVs approach and likely track across wrn
portions of cntl NC, initially virga or patchy very light rain there
this afternoon-evening may become steadier with top-down
moistening/lowering ceilings overnight-Tue morning. Low temperatures
will be in the 60s.

&&

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
As of 355 AM Monday...

The models indicate mid/upr-level ridging over the wrn Atlantic will
continue to strengthen and bulge nwwd across the South Atlantic
coast, while a trough will deamplify across the TN and OH Valleys.
Between the two, an associated upr-level jet streak will focus right
entrance region divergence, atop convectively-enhanced and weakly
perturbed mid-level flow, across the srn Appalachians and wrn
Carolinas.

At the surface, Canadian high pressure will remain over the Middle
Atlantic, while differential diabatic heating courtesy of upslope
and isentropic ascent over the wrn Carolinas will favor
wedge frontogenesis over the Foothills and srn and wrn Piedmont.

Lift, clouds, and rain will become focused and maximized from the
east facing slopes of the Appalachians ewd and into the wrn/srn
Piedmont, while influence from the wrn Atlantic ridge will maintain
mainly dry, and warmer conditions through the Coastal Plain. In
fact, the developing wedge front will probably yield an even
stronger gradient in temperatures than what the official forecast of
around 70 or so in the nw Piedmont to mid 80s in the Coastal Plain
depicts, with the former region likely to remain in the 60s
throughout the day if clouds and light rain materialize as expected.
A few convective elements, fueled by weak elevated instability,
warrant a slight chance of thunder in the vicinity of the wedge
front (ie. over the srn and wrn Piedmont) by late Tue night-Wed
morning, with low temperatures a couple of degrees milder but still
in the 60s.


&&.

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 1255 AM Monday...

The two primary surface features in the extended forecast will
remain nearly steady-state through the middle of the week into the
weekend. The first is the front that moved through North Carolina
Friday which has become a stationary front across northern Florida,
while the second is high pressure over southeastern Canada and the
northeastern United States. An upper trough which will be over the
Appalachian Mountains Wednesday and Thursday will eventually
dissipate, but around that time, the eastern edge of the surface
front will eventually rotate west towards the Carolinas coastline,
with a weak low possibly developing. The result will be diurnally
driven showers and thunderstorms, although soundings indicate that
instability for thunderstorms will be minimal during the first part
of the extended forecast.

High temperatures will be below normal through the period as a
result of persistent northeast winds. Wednesday is the coolest day
in the extended forecast, with highs ranging from the upper 70s in
the Triad to the upper 80s in southeastern counties. Depending on
the strength of the high pressure to the north and whether a cold
air damming wedge is able to continue into Wednesday, those forecast
highs could be 3-5 degrees too warm from the Triangle to the west.
Highs should generally be in the 80s through the rest of the period -
any readings in the 90s would be isolated. Lows will be in the 60s
and lower 70s.

&&

.AVIATION /11Z MONDAY THROUGH FRIDAY/...
As of 655 AM Monday...

Despite the presence of Canadian surface high pressure that will
will extend across the Middle Atlantic, increasingly moist swly flow
aloft will favor periods of multi-layered, VFR range cloudiness and
virga through the 12Z TAF period. Some of that virga may reach the
ground in the form of very light, VFR rain mainly at INT/GSO tonight-
Tue morning.

Outlook: Areas of stratiform rain and flight restrictions will
probably develop at INT/GSO Tue, then continue at times through most
of the upcoming week. Some convective elements and embedded thunder
may also result there by early Wed. Probability of rain and flight
restrictions will be less at ern sites.

&&

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

&&

$$

SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...Green
AVIATION...MWS