999
FXUS62 KRAH 272331
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
730 PM EDT Fri Jun 27 2025

.SYNOPSIS...
A backdoor front will become quasi-stationary over southern VA and
far northern NC through tonight, then return north as a warm front
across the Middle Atlantic coast on Saturday. A mid and upper-level
ridge will otherwise weaken while drifting from the southern Middle
Atlantic to near and east of Bermuda this weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 300 PM Friday...

In addition to the forecast rationale from this morning, which
remains valid, there is also a chance that aggregate outflow from
storms over the Blue Ridge will spread sewd across the Foothills and
nw/nrn Piedmont through this evening, as indicated by the NAM Nest,
HRW FV3, and HRW NSSL, and as supported by visible satellite trends
that indicate the outflow has been moving sewd at 5 or so kts and
has reached the UKF to MRN vicinity in the past hour.

Cyclonic flow around the nearly stationary, pre-frontal low over the
nrn Coastal Plain may serve to draw the backdoor cold front slightly
farther swd into the nrn NC Piedmont very late tonight-early Sat
morning, such that an area of post-frontal, low overcast may edge to
near I-85 by 12Z Sat. It will otherwise remain unseasonably mild and
humid, with near persistence lows in the 70s.


.PREV DISCUSSION... /ISSUED 1125 AM EDT Fri Jun 27 2025/

A strong backdoor cold front and differential heating zone evident
in satellite and surface observational data over far srn VA this
morning, with a pronounced frontal inversion evident immediately
behind it in the 12Z WAL and IAD RAOBs, may make a little additional
swd progress into far nern NC today, before becoming quasi-
stationary there through tonight. A broad pre-frontla trough, and
weak low centered over the nrn Coastal Plain of NC this morning,
will otherwise remain in place.

While a slight chance of convection will exist within the broad, pre-
frontal convergence axis throughout cntl NC, where strong diurnal
heating will yield persistence lwr-mid 90s and a moderately unstable
and weakly inhibited airmass, the relative greatest chance and
coverage of storms may result within the moisture convergence max
along and immediately ahead of the front and low over the nrn-cntl
Coastal Plain and ne Piedmont. Continued very weak wind profiles
below a lingering 50 kt ely jet at the tropopause will favor slow
and erratic cell motions, with cloud layer mean wind of only 5 or so
kts from the south. A combination of that weak flow and PWs forecast
to increase to around 1.75" will favor brief downpours and strong to
tree-damaging downburst winds from pulse cells.

&&

.SHORT TERM /SATURDAY...
As of 355 PM Friday...

The mid/upr-level pattern over the Southeast will weaken/flatten, as
the long-standing heat-producing ridge from recent days drifts
toward Bermuda and weakens, and a mid/upr-level low weakens over the
srn Appalachians. Sly flow between the two will direct a plume of
high PWs (ie. 1.8 to 2") across cntl NC.

At the surface, a backdoor front, and probable early morning
overcast over far nrn NC and especially VA in the morning, will
retreat nwd across the Middle Atlantic coast through the day, while
a persistent Piedmont/Sandhills trough will otherwise continue to
extend swwd across cntl NC.

With little to no change in airmass over cntl NC, temperatures
should be generally persistent, unseasonably hot ones mostly in the
lwr-mid 90s that will contribute to a moderately unstable and weakly
inhibited airmass once again by early afternoon. Pulse cells should
tend to focus along the surface trough and subsequent outflow over
the Piedmont/Sandhills, with lesser chances/coverage in the Coastal
Plain. A combination of continued weak deep layer flow and high PWs
will favor brief downpours and a mainly urban flood risk, and strong
to tree-damaging downburst winds.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
As of 300 PM Friday...

* Typical summer pattern across NC much of this week with above
  normal temperatures and daily shower/thunderstorm chances

* Increased shower/storm chances Tuesday/Wednesday, turning drier
  Thursday/Friday

The forecast will feature a fairly typical summertime pattern
through early next week with Bermuda high pressure in place at the
surface and aloft. Daily shower and thunderstorm chances are
expected through Monday, with the highest chances generally favored
in the western Piedmont. Afternoon highs will top out in the low to
mid 90s with lows generally in the lows 70s (west) to the mid/upper
70s (southern Coastal Plain). Heat indices will once again range
from the upper 90s to lower 100s. Certainly not cool, but not as
high as what was seen earlier this week.

Looking ahead to Tuesday, a longwave trough will migrate out of the
northern Plains, sharpening as it approaches the western slopes of
the Appalachians. Modest moisture advection ahead of the trough and
the attendant surface front should promote the development of more
widespread shower and thunderstorm activity across the area Tuesday
afternoon and evening. PW`s will top out around 2" ahead of the
front and with MLCAPEs running anywhere from 1000-1500 J/KG, areal
coverage of storms should be noticeably higher than previous days.
With synoptically driven support in the form of the trough, some
some storms could be strong to severe. There is still some inherent
uncertainty at this lead time with respect to how far south this
front will make it before washing out/dissipating but the threat for
more widespread precip chances is certainly agreed upon by the
models. PoPs will range anywhere from 60-80 percent Tuesday
afternoon/evening, with the highest values in the west. The front
should slowly sag through the area Wednesday, eventually
stalling/washing out across the Sandhills/southern Coastal Plain on
Thursday. In the wake of the trough, mid level subsidence and drying
should yield lesser precip chances Thursday and Friday.

Temps Tuesday through Thursday will once again range from the low to
mid 90s, with overnight lows in the low to mid 70s. The exception
will be Wednesday when highs may only reach the upper 80s with the
front overhead and associated increased cloud cover.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
As of 730 PM Friday...

For the remainder of the evening, isolated showers and embedded
storms remain possible. The greatest chance for remaining impacts to
the TAF terminals from these showers looks to be at FAY and RWI. Any
showers/storms are expected to diminish with the loss of daytime
heating. Overnight, ceiling restrictions are possible at INT/GSO as
a backdoor cold front may move south into the northern portions of
the region, which would bring low stratus if it reaches the region.
Additionally, visibility restrictions are expected again late
tonight/early morning at RWI. Otherwise, TAF sites should remain VFR
until the risk of showers/storms increases once again Saturday
afternoon, with the greatest chance for restrictions expected in the
west.

Outlook: After generally scattered, diurnally-driven convection
through the weekend, shower/storm chances will increase with the
approach of an upr-level trough and surface cold front next Tue-Wed.

&&

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

&&

$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...Leins
AVIATION...Helock/MWS