-- Discussion containing changed information from previous version are highlighted. --
361
FXUS62 KRAH 101025
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
625 AM EDT Thu Jul 10 2025

.SYNOPSIS...
Disturbances in unseasonably moist, southwesterly flow aloft will
interact with a surface trough over the Middle Atlantic and
Carolinas through Friday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 340 AM Thursday...

* A Flood Watch is in effect today for all of central NC through at
  least 2 AM then only the Coastal Plain until 5 AM.

* Weakly organized storms will be capable of torrential rainfall,
  which may result in scattered flash flooding, as well as strong to
  locally severe wind gusts.

Water vapor imagery and RAP analysis shows a positively-tilted
trough axis extending from southern Quebec southwestward through
the Ohio Valley into the ArkLaTex region. Ahead of this feature,
continued moist southwesterly flow aloft will keep anomalous
deep-layer moisture in place over the Mid-Atlantic into the
Southeast. The trough axis is expected to slowly sag eastward
through this evening and reach the eastern Carolinas by Fri
morning. Regional radar imagery also show several embedded MVC`s
rotating through the mean flow over the southern Appalachians
as well as central SC and southeastern GA.

After the widespread early morning stratus gradually scatters out
through mid-morning, a continued warm and moist airmass, with
surface dew points in the low/mid 70s, should result in 1500-2500
J/kg of MLCAPE with diurnal heating. Anomalous deep-layer moisture
in place will favor relatively early convective initiation over
western NC and SC due to low convective temps and weak synoptic
ascent. This should result in scattered to numerous showers and
storms once again through the afternoon as convective outflows
spread into our area. Weak steering winds and deep-layer shear <
20kts will result in slow storm motions of efficient heavy rain
producing storms, only propagating along the development of common
cold pools and storm scale MCVs.

Flooding and severe risk: Greatest concern will once again be
scattered instances of flash flooding due to a large portion of the
Piedmont particularly sensitive to additional rainfall (the area
from the Triad to the Triangle to Fayetteville to Albemarle has
experienced 2 to over +10 inches within the past 7 days, which
is 200 to +600% of normal). 00z HREF and 18z REFS are in good
agreement that the rainfall footprint may look closer to a more
classic summer-time pattern where most places will see at least
trace amounts to 0.5-1", but concentrated areas of 2 to 5+
inches will again be possible. Both ensemble systems highlight
the greatest probabilities for concentrated higher amounts to be
bimodal, one area over the western/southern Piedmont into the
western Sandhills, and another somewhere over the Coastal Plain.
However, it is important to note that in these patterns,
locally higher and potentially significant rainfall amounts can
occur anywhere. Additionally, one or two strong to severe
convective clusters will be capable of producing strong to
severe winds, but with heavily saturated soils over a large
portion of the Piedmont, scattered downed trees will be possible
even with sub-severe wind gusts.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
As of 355 AM Thursday...

A mid/upper trough will move east from Quebec and New England into
the Canadian Maritimes on Friday and Friday night. Meanwhile a
shortwave trough initially over eastern NC will push east and
offshore, turning the mid-level flow to a more W/NW direction. This
will bring in some drier air, with 2+ inch PW values confined to far
southern and eastern portions of central NC. This combined with weak
height rises behind the departing shortwave mean coverage of
convection should be significantly less than previous days,
especially over the northern Piedmont. This may help temperatures
get a bit warmer than today, with forecast highs in the upper-80s to
lower-90s (near normal).

Still, dew points in the 70s and good surface heating will result in
another day of 1500-2500 J/kg of CAPE, so scattered to locally
numerous showers and storms will be possible in the afternoon and
evening, particularly where any remnant outflows are left over from
today`s storms. The best coverage and intensity should be across the
Sandhills and Coastal Plain, coincident with the greatest deep-layer
moisture. However, scattered showers and storms will still be
possible farther west along the Piedmont surface trough that will be
in place. Very weak mid-level flow (less than 15 kts) should
preclude an organized severe threat, but still can`t rule out an
isolated wet microburst, and SPC has our entire area in a marginal
(level 1 of 5) risk for severe storms.

The heavy rain threat certainly looks less than previous days, but
WPC still has central NC in a marginal (level 1 of 4) risk for
excessive rainfall as well. Think this will be mostly confined to
the south and east, where the LPMM on the 00z HREF depicts isolated
pockets of 1-3 inches, but it isn`t nearly as widespread, and some
will depend on how much rain falls there today. Given how much rain
has fallen over the Piedmont this week, FFG values there are quite
low, so that area will still bear watching as well.

Convection will diminish in the late evening and overnight hours
with loss of daytime heating. Mild lows in the lower-to-mid-70s are
expected.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 355 AM Thursday...

The weak shortwave off the Southeast US coast will lift NE on
Saturday and Sunday, getting replaced by a building subtropical high
over the Gulf. W/NW flow around the high will continue to bring
drier air into central NC, with any 2+ inch PW values still confined
to southern and eastern portions of the area. Still, a combination
of surface dew points in the 70s, moderate destabilization, a
Piedmont surface trough, and potential upper impulses mean scattered
showers and storms can`t be ruled out anywhere. POPs are greatest in
the south and east, but even there convection should be mainly
scattered in nature. Weak flow aloft should continue to preclude an
organized severe threat.

As the Bermuda surface high begins extending back westward and moist
southerly flow increases off the Atlantic, increasing deep-layer
moisture looks to yield higher shower/storm chances once again from
Monday through Wednesday, though overall QPF still isn`t as high as
what we have gotten in recent days, as there will be a lack of upper
forcing with the subtropical ridge building into the Southeast US. A
mid/upper trough looks to move east across the Great Lakes and
Northeast US early next week, dragging a cold front to its south,
but at this time the front looks to largely dissipate by the time it
reaches the Carolinas.

Forecast highs from Saturday through Monday are still upper-80s to
lower-90s. Some heat indices in the low-100s will be possible in the
south and east. A slight cooldown may commence on Tuesday and
Wednesday depending if the front is able to reach us, but highs
should still be within a few degrees of normal. Lows each night will
be in the lower-to-mid-70s.

&&

.AVIATION /11Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
As of 625 AM Thursday...

Prevailing LIFR-IFR cigs developed across the 4 northern terminals
while remaining fairly patchy around FAY. Those ceilings are
expected to then persist through mid-morning, then lift through MVFR
and scatter to VFR through late morning to midday. Scattered to
locally numerous convection is expected redevelop with daytime
heating of an unseasonably moist airmass, and under the influence of
a series of mid-level disturbances that will track across the
region, later this afternoon-evening. Timing of the PROB30s was
slightly tweaked based on the latest available guidance.

Outlook: Another day of diurnally-driven showers and thunderstorms
appears likely for Friday, with coverage more scattered Saturday,
Sunday, and Monday. In addition, considering the early morning
fog/stratus that occurred this morning, early morning restrictions
could continue through the next several days with minimal change in
air mass expected.
-- End Changed Discussion --

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
Flood Watch through late tonight for NCZ007>010-021>025-
038>040-073>076-083>086.
Flood Watch through late tonight for NCZ011-026>028-041>043-
077-078-088-089.

&&

$$

SYNOPSIS...MWS
NEAR TERM...Swiggett
SHORT TERM...Danco
LONG TERM...Danco
AVIATION...Swiggett/MWS