123
FXUS62 KRAH 131720
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
120 PM EDT Sun Jul 13 2025

.SYNOPSIS...
An outflow-reinforeced, backdoor front will dissipate over eastern
and central VA and NC through Monday. Sub-tropical high pressure
will otherwise extend from near Bermuda to the Carolinas throughout
the upcoming week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 400 AM Sunday...

* Persistently hot and humid, with scattered, diurnal convection
  capable of isolated damaging wind gusts and flash flooding Sunday

The models indicate a sub-tropical anticyclone in the mid/upr-
levels, centered in 00Z/13th RAOB data over the nern Gulf and FL
Panhandle, will hold firm, or drift slightly wwd into AL. A narrow
mid and upr-level ridge, and maximum in PWs around 2", will extend
from its northeast and across the Carolinas. The ridge axis will be
flanked 1) to its east by an impulse/vort max now evident in water
vapor satellite data about 70 miles ese of Cape Hatteras, which will
drift generally sswwd and parallel to the coast of the Carolinas,
and 2) a couple of impulses centered near the nrn WV Panhandle and
wrn OH, respectively, which should both become increasingly-sheared
as they drift newd and across the Middle Atlantic.

At the surface, broad low pressure now centered at 1015 mb over cntl
NC will remain over VA and the Carolinas. An outflow-reinforced
backdoor front, evident in surface observational and earlier
regional radar data, extended through the low from the srn Outer
Banks wwd to near RDU then nwd to near LYH and SHD. The front will
probably become further strengthened/reinforced by areas of fog and
low stratus that will develop on its cool side from nern NC through
cntl and ern VA in the next few hours and which will slow diurnal
heating and enhance differential heating/frontogenesis. A sea breeze
will also again develop and spread inland later this afternoon
through evening.

Showers/storms today will probably initiate first along the
aforementioned backdoor front by early this afternoon, while others
will develop in the higher terrain and propagate ewd along outflow
and across the srn Middle Atlantic (NC/VA) Piedmont, probably aided
by the mid/upr-level impulses over the Middle Atlantic. Additional,
pulse/multi-cells, amid weak steering flow and shear (less than 10-
15 kts), will develop/pulse along outflows - with generally scattered
coverage that may have a relative minimum over the srn Piedmont,
where the above forcing mechanisms will be least prevalent and
influential. Pulse, wet microbursts and locally very heavy
rain/flooding in slow-moving cells may result on an isolated basis.
Convection may linger while drifting ewd and across particularly the
nrn Piedmont through this evening, along outflow and the lingering
backdoor front.

It will otherwise be persistently hot and humid as Sat, with heat
index values that should again reach 100-105 F over the ern half of
cntl NC, prior to convective initiation and outflow cooling. It will
be continued mild and muggy/humid tonight, in the low-mid 70s, with
areas of fog in the Coastal Plain and ne Piedmont.

&&

.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 225 AM Sunday...

A weak surface trough will move across the area Monday resulting in
scattered to numerous showers and storms. The best chance for storms
will be in the afternoon and continuing through much of the evening
and some of the overnight hours. Microbursts with damaging wind
gusts could be possible within these storms. PW values will be above
average around 2 which will continue the threat for heavy rain and
flash flooding. WPC has most of Central NC in a marginal risk and
portions of the Northern Piedmont in a Slight risk for Flash
Flooding Monday. While SPC has not introduced any threat above
general thunderstorms yet, MLCAPE values of 1500 to 2200 J/kg could
warrant a few localized severe storms. Temperatures will be in the
low to mid 90s with one more day oh heat indices in the low 100s
across the Triangle region. Lows overnight will be in the low to mid
70s.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
As of 225 AM Sunday...

Tuesday will be similar to Monday, with the trough exiting the area
and a weak cold front dipping down into the area. A few isolated
morning showers will turn into numerous to widespread storms, again
some could be severe. WPC has all of Central NC in a marginal risk
for Flash Flooding as some storms could be slow moving and produce
heavy rain at times. The front is expected fizzle out west of the
area as weak high pressure tries to build in mid week. Afternoon
diurnally driven scattered showers and storms will be possible each
afternoon and early evening through the rest of the forecast period.
Over the weekend another trough develops thus, expect increased
precip chances Friday- Sunday especially in the afternoon and
evening hours.  Temperatures in the long term will range in the
upper upper 80s to low 90s with lows in the low to mid 70s.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
As of 120 PM Sunday...

Storms have developed along a surface convergence axis across the
eastern Piedmont and Coastal Plain. The strongest storms are
presently between RDU and RWI. Developing outflow boundaries should
allow convection to impact these two terminals, with the favored
time window of 18 to 23z. Storms are also expected to impact FAY
along this surface boundary during this same time frame, though
confidence is somewhat less for IFR conditions. Confidence is the
lowest for storms reaching GSO and INT, so have kept the PROB30
group in place between 20z and 01z Mon. A late-evening batch of
scattered showers could impact these terminals between 02 and 05z
with a weak disturbance aloft, but confidence was too low to
introduce sub-VFR restrictions. A period of IFR to LIFR conditions
in possible fog is expected at RDU, FAY, and RWI, with the highest
confidence at RWI and FAY. VFR should prevail after sunrise, with
scattered showers and storms possible again by 18z Mon.

Outlook: Sub-tropical high pressure over the western and swrn N.
Atlantic will favor a typical summertime regime of scattered aft-eve
convection and patchy fog/stratus, with the latter likely to shift
from the Coastal Plain (ie. RWI and FAY) early week to the wrn
Piedmont and Foothills (ie. GSO/INT) by mid-week.

&&

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

&&

$$

SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...CA
LONG TERM...CA
AVIATION...Kren/MWS