121
FXUS62 KRAH 052254
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
654 PM EDT Tue Aug 5 2025

.SYNOPSIS...
Canadian high pressure will extend across the Middle Atlantic this
week, although a series of disturbances in moist, southwesterly flow
aloft will pass overhead.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 220 PM Tuesday..

*  There is a Slight Risk for excessive rainfall across most of the
   Piedmont, with a Marginal Risk elsewhere across central NC.
   Isolated flooding is possible, especially in urban, flood-prone
   locations across the NC Piedmont through tonight.

Aloft, a trough over the TN/OH Valleys will shift slightly ewd
through tonight, remaining west of the Appalachians, bookended by
highs over the Desert Southwest and wrn Atlantic. A pair of mid-
level disturbances will track across the region, one currently over
wrn SC/NC, moving across this aft/eve, and the next currently over
srn AL, moving across late tonight/early Wed. At the surface,
Canadian high pressure continues to ridge swwd over the nrn and wrn
Piedmont, with a weak area of low pressure over SE Alabama as of
15Z. With the ridge remaining in place (possibly being shunted a bit
nwwd), this low should track newd across GA, SC, and ern NC,
generally along the quasi-stationary front and east of the wedge
front, through tonight. The ongoing rain over the nrn and wrn
Piedmont should keep the CAD locked in through tonight, even with
the expected break in precipitation this evening/early tonight
between the two disturbances aloft. Along and east of the wedge
front, showers and storms will be possible with each passing
disturbance, with the greatest chances for thunder across the
Sandhills and srn Coastal Plain. Temperatures have struggled to get
into the mid 60s over the NW Piedmont today, where highs should top
out in the mid 60s. Elsewhere, generally expect highs in the low 70s
to low 80s. Lows tonight should range from low 60s NW to upper 60s
SE.

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
As of 232 PM Tuesday...

Showers will likely be ongoing across the west early Wednesday
morning triggered by additional mid-level impulses and convergence
along the lingering wedge front.  This convection will likely slowly
ooze eastward through the Piedmont by mid-day and into the
Sandhills/Coastal Plain in the afternoon/evening time period.

Flash flooding potential: There is some concerning signal in the
guidance for Wednesday wrt to flash flood potential.  First, the 12Z
HREF 6 hrly LPMM field hints at possible higher rainfall totals
somewhere between Winston Salem and Raleigh from 12Z to 18Z. While
CAM-simulated elevated instability is higher compared to Tuesday,
any rain that develops in this area will be fighting lingering low-
level stability from the lingering CAD wedge. As such, not entirely
sure if these higher rainfall totals will be realized in this
vicinity. Nonetheless, the signal is there and thus isolated flash
flooding may be possible in the Triad to Triangle areas Wednesday
morning.

As we progress into the late morning/early afternoon period, the 12Z
HREF 6 hrly LPMM hints at another signal for potentially high
rainfall totals in the Sandhills/southern Coastal Plain (with some
continuity from previous runs).  The HRRR/WRF/NSSL CAMs are all pin-
pointing this area with pretty high rainfall amounts (some bullseye
as high as 5 inches) Wednesday afternoon and early evening.
Conceptually, this may make sense as these areas will be east of the
wedge front, and will likely warm up into the lower to mid 80s
generating upwards of 1000 to 1500 J/kg of SBCAPE. 1 to 3 hrly FFG
is a bit higher in this vicinity compared to the northwest Piedmont,
but if these higher rain rates are realized, urban areas from
Fayetteville to Goldsboro could see isolated flash flooding as well.

While the main band of convection should move southeast of the area
by early Wednesday night, lingering elevated instability and weak
forcing aloft may trigger additional convection over the Piedmont.
Don`t think we`ll see as high of rain rates with this convection,
but can`t rule out isolated flooding if a cell goes stationary over
an urban area.

Daytime highs will range from around 70 in the Triad to mid 80s in
the far southeast.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
As of 220 PM Tuesday...

* Below normal temperatures expected through the weekend, before
  returning to near normal early next week.

* Unsettled weather expected each day, with tropical moisture
  increasing rain chances through the weekend.

The cool, high pressure will slowly weaken and shift eastward
through the extended period, leaving weak ridging over the region by
early next week. This will allow the cool temperatures to slowly
moderate each day, returning to near normal by Monday. High
temperatures should increase from the mid 70s to mid 80s on Thursday
to mid-to-upper 80s by Monday, with the potential for low 90s to
return by Tuesday.

Rain chances Thursday through Saturday are a bit uncertain as they
will be influenced by a potential tropical development off the
coast. The NHC has increased the formation chance of the disturbance
to 40% and indicated that a low pressure system is expected to
develop in the next day or so. Models are still showing differences
in potential track and intensity, making it unclear how much rain,
we will get from this system. Regardless of development, increased
tropical moisture will allow for daily shower and storm chances.
Sunday through Tuesday, a typical pattern of diurnally induced
showers and storms should return.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
As of 651 PM Tuesday...


Light rain continues to collapse east-southeast this evening.
KINT/KGSO have briefly lifted to VFR which could continue for a few
hours here. However, as we progress into the overnight hours,
additional showers will be possible at KINT/KGSO which should also
promote MVFR/IFR ceilings and visibilities through to the end of the
24 hr TAF period. For sites further east, think we`ll mostly see VFR
(with brief periods of light rain) through the early overnight
period, however KFAY/KRDU could possibly drop to MVFR ceilings near
sunrise Wednesday.

There is a signal in the guidance that heavier rain/tstorms may be
possible by early afternoon at KRDU/KFAY and perhaps KRWI late
afternoon/early evening which could promote periods of sub-VFR
conditions at those sites as well.

Outlook: Areas of stratiform rain and flight restrictions will
continue over the Piedmont through Wed-Wed night, as a series of
disturbances in moist, swly flow aloft pass overhead. Overnight-
morning IFR-MVFR ceilings will also be favored over the Piedmont
through most of the week. Both the probability of rain and flight
restrictions will be less at ern sites.

&&

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

&&

$$

SYNOPSIS...MWS
NEAR TERM...KC
SHORT TERM...Luchetti
LONG TERM...Helock
AVIATION...Luchetti/MWS