858
FXUS62 KRAH 101755
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
155 PM EDT Sun Aug 10 2025

.SYNOPSIS...
High pressure centered off the Mid-Atlantic will continue to extend
down into central North Carolina tonight. This high pressure will
gradually weaken and move further offshore on Monday, allowing for a
return to more typical summertime weather, with scattered late-day
showers and storms into mid week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 155 PM Sunday...

A surface frontal zone is largely located along the coasts of GA and
SC. This sloped frontal zone arcs to the north and west in the 850
to 700 mb layer, located approximately across east-central GA into
central SC and far SE NC. Satellite imagery also reveals a notable
swirl or area of low pressure near Savannah GA. This may be a
remnant MCV from convection down there, but regardless the model
guidance shows it tracking somewhat northward into portions of
central SC by 12z Mon.

A disorganized area of isolated to scattered showers continue to
move north and northwestward from the NC coast and Coastal Plain
tied to the sloped frontal zone and along higher PW`s above 2+
inches. Instability is somewhat lacking, though, with mesoanalysis
only showing some 500 J/kg, mainly over the eastern Sandhills and
Coastal Plain of central NC. This instability drops off over the
Piedmont, owing to drier air and where dewpoints are still in the
low to mid 60s. Best chance of showers will be across our southern
zones into early evening. Most CAM guidance shows the shower
activity weakening once it approaches the Triangle and Piedmont, and
activity waning nearly everywhere after sunset as resultant outflows
stabilize the boundary layer. This makes sense, though cannot rule
out some isolated showers overnight, especially as low-level
moisture gradually increases and from weak lift from the
aforementioned low along the frontal zone slowly edging north. WPC
retained a marginal risk of excessive rain in our southern zones
this evening, though think chances of heavy rain is minimal given
weak forcing overall.

Low temperatures tonight should be warmer in the upper 60s to lower
70s as moisture overall increases dewpoints. Low stratus as well is
expected to build in from the south, along with some isolated patchy
fog. A few isolated showers or drizzle cannot be ruled out with
moist upglide in place, especially across the Triad, where shallow
upslope will fuel lower ceilings.

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...
As of 1250 PM Sunday...

* Mostly scattered slow-moving showers/storms Monday afternoon may
  result in isolated urban flooding through the evening hours.

Further gradual moistening of the thermo-profile is expected within
the southeast to southwesterly flow up to 500 mb and increase PWAT
values above the 90th percentile for a majority of the forecast area
by Mon afternoon. Widespread morning stratus over the Piedmont
should slowly lift through the morning hours becoming scattered
cumulus by the early afternoon. This should allow for heating of the
moistening low-level airmass, characterized by a return of
widespread 70s dew points, and result in 500-1500 J/kg of MLCAPE by
the mid-afternoon.

Anomalous moisture, deep warm-cloud layer > 10k feet, tall skinny
CAPE profiles, and slow mean-wind steering flow will result in
efficient warm rain processes with slow moving torrential downpours.
Updraft depth and lack of persistent updraft development should
preclude widespread flooding concerns. Most locations may only see a
trace to a quick 0.25" with up to an inch possible. However, where
updrafts collide along outflow boundaries will be the favored areas
for enhanced rainfall totals and resultant flooding concerns,
especially over urban areas and poor drainage locations. HREF LPMM
and probabilities of > 3" in 24 hours suggest the most likely
location will be somewhere across the northern Coastal Plain where
seabreeze interaction off the Chesapeake is possible and localized 3-
6" can`t be ruled out. However, enhanced but highly localized
rainfall totals could occur anywhere over central NC (10-30%
chance).

Severe threat remains very limited with marginal instability, poor
lapse rates through the thermo-profile, and meager DCAPE expected.
Highs should reach into the upper 70s to low 80s with mild overnight
lows in the upper 60s to low 70s.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
As of 155 PM Sunday...

Surface high pressure that has been well established for the last
several days northeast of here will begin the period offshore of New
England, but will at last be shunted east of the area. Ridging
associated with the surface high has kept a northerly component to
the wind locally for quite a while, but the low level flow Tuesday,
Wednesday, and Thursday will have a sustained southerly component
for several days. This will finally allow for a return to normal
highs by Thursday, around 90 degrees, which also appears to be the
warmest day of the period (although Friday won`t be too far behind).
There could be some isolated heat index values near 105, but at this
time it does not appear that an advisory would be needed. Overnight
lows will be around 70 degrees.

Although a surface front will cross the Great Lakes mid week and
linger near the Mason-Dixon line going into the weekend, the front
should not have much impact locally on the weather. Diurnally driven
showers and thunderstorms are expected through the period, with
greater coverage on Tuesday and Wednesday (40-70% of the area) and
decreased coverage the rest of the period (30-50%).

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
As of 155 PM Sunday...

There is reasonably high confidence in VFR for much of the TAF
period into early this evening. Isolated to scattered showers tied
to a sloped frontal zone to the south of the TAF sites will slowly
progress north and northwestward, perhaps briefly impacting FAY/RWI
into early evening. Overall, instability is somewhat lacking,
especially with northward extent. For the 18z TAF, we considered
removing thunder at FAY, but still think it is possible so left the
forecast unchanged. We do not think showers will survive at RDU, but
cannot rule out a brief shower between 23-02z. Guidance continues to
suggest areas of LIFR to IFR stratus developing across all
terminals. Some guidance hints at earlier arrival of the IFR or
lower stratus, between 03-06z, while the median/avg time is around
06-08z. We opted for the median time given closer agreement with NBM
probabilities and climatology. Some LIFR stratus is still possible
across the northern sites, with areas of IFR visibilities. Stratus
should lift near or before 15z, with MVFR gradually becoming VFR Mon
afternoon, slowest to lift at GSO/INT. An increased chance of
showers/storms is favored Mon afternoon with deeper moisture, so
included VCSH at the end of the TAF period.

Outlook: Scattered showers/storms will be possible Mon aftn/eve,
dissipating in the late evening. These diurnally driven
showers/storms will be possible through the upcoming week. Patchy
fog or stratus will also be possible each morning.

&&

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

&&

$$

SYNOPSIS...Kren/Hartfield
NEAR TERM...Kren
SHORT TERM...Swiggett
LONG TERM...Green
AVIATION...Kren