963
FXUS62 KRAH 031757
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
157 PM EDT Sun Aug 3 2025

.SYNOPSIS...
Cool Canadian high pressure will extend into the region from the
north through the weekend into Monday.

&&

.NEAR TERM /TODAY THROUGH TONIGHT/...
As of 1250 PM Sunday...

* Another cool night ahead

Central NC will remain under the influence of a cool, dry air sfc
ridge, while an area of low pressure system off the NC coast
continues to drift slowly east, moving further offshore.

Daytime mixing has lowered surface dewpoints into the lower into the
mid to upper 50s across much of the area, bringing very comfortable
humidity levels as high temperatures top out in the upper 70s to
lower 80s.

A persistent broken deck of stratocumulus clouds across the far
western/northwestern Piedmont is expected to scatter out during the
late afternoon and evening. Until then, a stray shower or sprinkle
can`t be completed ruled out. Intermittent NELY gustiness of 15 to
20 mph will diminish as the sun starts to set.

Tonight, mostly clear skies and the dry air will set the stage for
another cool night across central NC. Overnight lows will fall into
the 55-60 range across the north, to 60-65 across the south---about
4-8 degrees below normal for this time of year.

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...
As of 155 PM Sunday...

Surface high pressure centered over eastern Ontario will move east
into Quebec on Monday and Monday night, with associated ridging
extending from New England down the lee of the Appalachians, setting
up cool NE flow and a CAD type regime over the southern Mid-
Atlantic. In the mid and upper levels, a trough over the lower MS
Valley will slowly move east, as ridging strengthens off the
Southeast US coast. This will turn the flow from WSW to a more moist
SW direction late Monday, with below-normal PW values giving way to
near and above normal PW values (1.5-2+ inches) across much of
central NC on Monday night.

The above pattern will bring increasing mid and high clouds on
Monday and Monday night, especially across the west. Other than a
slight chance of a shower in the far SW, weather conditions during
the day Monday will be dry and pleasant, with below-normal
temperatures. Highs will be in the lower-to-mid-80s, and the
forecast again lowers dew points below NBM, mixing them out into the
50s in the afternoon everywhere but the far SE, as is already
happening today.

Model guidance depicts a good signal for some rain spreading north
into western and parts of central NC on Monday evening and Monday
night. The deterministic GFS is the one exception as it keeps our
region largely dry, but it is an outlier as all high-res models and
even a good number of its own ensembles have some precipitation.
Meanwhile the deterministic ECMWF is wet for our entire area, an
outlier on the other end. So leaned toward the compromise solution
the high-res models generally depict, with POPs increasing to chance
over the western Piedmont on Monday night, and no POPs in the east.
Given the rain this far north should be primarily isentropic lift
driven with very little if any instability, any amounts through 12z
Tuesday will be light, around a tenth to quarter inch at most based
on the 12z HREF. The cloud cover will keep low temperatures milder
than previous nights and close to normal, ranging from lower-60s in
the far NE (where it will be clearer) to mid-to-upper-60s elsewhere.

&&.

.LONG TERM /TUESDAY THROUGH SUNDAY/...
As of 1250 PM Sunday...

* Long-duration northerly winds keep temperatures below normal
  through Friday.

* Light to moderate rain with embedded showers possible Tuesday
  through Wednesday may lock in a renewed classic CAD over the
  Piedmont.

Tues-Wed night: The combination of strong surface high pressure
shifting over the Northeast and waves of low pressure along the
stalled front over the western Atlantic will keep a steady fetch of
northeasterly flow at the surface more-or-less through the forecast
period. A weak mid/upper level trough over the OH Valley into the
lower MS Valley will direct a return of near normal PWAT overtop of
the wedge of continental high pressure at the surface. Perturbed
southwesterly flow and waves of weak WAA will support a period of
above climo precipitation chances Tues through Wed night. Limited hi-
res guidance supports light/moderate stratiform rain moving through
western NC into the western Piedmont (including the Triad) Tues
morning. This should weaken/dissipate through early afternoon, but
may lock in the wedge across the western Piedmont through diabatic
processes through a majority of the day. The current forecast has
hedged in this direction, but with the GFS and its ensemble members
continuing to hold strong with minimal rain chances, have not
deviated too far from initial forecast. However, further forecast
refinements may be necessary as models that hold onto the wedge
suggest highs may be 10-15 degrees cooler in the typical damming
regime than current forecast may suggest. Overall rainfall in the
forecast area will be predominantly stratiform and result in low
rainfall totals of a tenth across the Coastal Plain to up to 0.75"
along the Yadkin River Valley.

Thurs-Sun: There is increasing model support for a weak/broad area
of low pressure to develop along the baroclinic front just off the
GA/SC coast (a separate area from where NHC is highlighting in the
western Atlantic) Thurs night into Fri. This area of low pressure
may continue to lock in the northerly flow over the forecast area as
the surface high to the north shifts off the New England coast, but
also increase precipitation chances, especially for the Coastal
Plain sometime between Fri into Sat night, as it drifts towards the
Carolina coast. Tropical characteristics are not expected at this
time.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
As of 1250 PM Sunday...

There is high confidence that VFR conditions will prevail through
the TAF period, supported by a cool and dry airmass.  Intermittent E-
NELY gustiness of 15-20 kts will diminish this evening.

Looking beyond 18z Mon: Predominately VFR conditions are likely to
continue through early in the week. However, rain rain chances will
gradually increase through mid to late week, potentially bringing
period of sub-VFR restrictions, especially during the afternoon and
evening.

&&

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

&&

$$

SYNOPSIS...Badgett
NEAR TERM...CBL
SHORT TERM...Danco
LONG TERM...Swiggett
AVIATION...CBL