097
FXUS62 KRAH 012224
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
625 PM EDT Thu Oct 1 2026

.WHAT HAS CHANGED...

* Increasing confidence in areas of fog, locally dense, early Friday.

&&

.KEY MESSAGES...
As of 320 PM Thursday...

1) Patchy dense fog will be possible late tonight and early Friday
morning across mainly the Coastal Plain and eastern Sandhills.

2) Temperatures will remain well above average ahead of a cold front
that will move south across central NC on Saturday.

3) Cloudy, much cooler, and periods of wet conditions will develop
in cold air damming later Sat through the weekend.

&&

.DISCUSSION...
As of 320 PM Thursday...

KEY MESSAGE 1... Patchy dense fog will be possible late tonight and
early Friday morning across mainly the Coastal Plain and eastern
Sandhills.

As winds go very light to calm in many spots, more fog and very low
stratus will be possible late tonight into early Friday morning
across portions of central NC, mainly to the east of US Highway 1.
Given the surface high will be centered farther offshore than this
morning, southerly flow around the high will bring more moist air in
the low levels from the Atlantic into those locations, with dew
points increasing to the mid-to-upper-60s. Thus model guidance
depicts a stronger signal for more widespread fog, locally dense,
reaching farther NW into our area compared to this morning. Any fog
will quickly dissipate after sunrise.

KEY MESSAGE 2... Temperatures will remain well above average ahead
of a cold front that will move south across central NC on Saturday.

A sub-tropical high currently centered near the coast of the
Carolinas will progress offshore today and settle across the
southwestern North Atlantic through the weekend.

At the surface, a ~1020 mb high now centered about halfway between
Bermuda and the NC coast will drift to near Bermuda, while extending
westward into the Southeast US, through Friday. Subsidence from the
subtropical ridge aloft, and southerly, "return" flow around the
Bermuda surface high, will contribute to additional warming of the
airmass over the Carolinas and another day of summerlike
temperatures on Friday. Low-level thicknesses should be about 5-10 m
higher compared to today, favoring high temperatures in the upper-
80s to lower-90s. Fortunately, Friday afternoon humidity levels will
again remain relatively low in the 40s percent courtesy of dewpoints
mixing out to the lower-to-mid-60s. Still, the NWS Experimental
HeatRisk is forecast to be Moderate across most of the region,
meaning those who are sensitive to heat, especially those without
cooling/hydration, are affected. Lows will also be above normal, in
the lower-to-mid-60s tonight and in the mid-60s to 70 on Friday
night.

KEY MESSAGE 3... Cloudy, much cooler, and periods of wet conditions
will develop in cold air damming later Sat through the weekend.

Not a whole lot of change from the previous forecast. Still expect a
positively-tilted srn stream trough/shear axis to progress slowly
across the Southeast and Carolinas this weekend, just downstream and
equatorward of a series of prominent shortwaves that will progress
through a broad trough that will become centered over ern Canada.
One nrn stream s/w will amplify as it tracks ewd across the nrn
Plains and upper MS Valley on Sat and across the Great Lakes and the
nrn mid-Atlantic/Northeast US Sat night and Sun. Expect a period of
enhanced lift as the s/w energy interacts with the trough/shear axis
over the region. The upper trough should amplify swd over the
Eastern Seaboard on Mon before shifting ewd and offshore Mon night.

At the surface, a front will settle swd across central NC Fri
night/Sat, becoming quasi-stationary across SC and southeastern NC
Sat night. A weak frontal wave is expected to lift newd along the
boundary on Sun/Sun night, which may help the front retreat north
and west a bit. Cool, strengthening high pressure will ridge swd
into the area in the wake of the front Sat/Sat night as it
progresses ewd from the Great Lakes to the Canadian Maritimes. A
brief period of CAD may develop over the region Sat night, possibly
lingering through Sun, especially with the expected rainfall acting
to lock in the wedge across the NW Sun/Sun night.

With all of the above in mind, expect rain to start Sat afternoon as
isentropic lift increases within the trough/shear axis and ahead of
the aforementioned s/w aloft and atop surface ridging, which will
help lock in a CAD airmass. Rain should continue through Sun
eve/night when the frontal wave finally moves away from the Carolina
coast. There is still some uncertainty wrt overall rainfall totals,
but generally expect 1-2 inches across central NC from Sat aft to
Sun night. The WPC has central NC in a Marginal Risk for excessive
rainfall on Sunday.

If the CAD does indeed lock in, and with the expected rainfall,
temperatures over the weekend will need to be adjusted downward
further.

A reinforcing cold front will move across the area Mon eve/night,
with cool Canadian high pressure building in behind it and dry
weather expected through mid-week.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
As of 625 PM Thursday...

VFR conditions are expected to start the TAF period. We continue to
monitor the potential for LIFR/IFR fog and/or stratus, mainly across
the eastern sites over the Sandhills and Coastal Plain, namely
FAY/RWI. The latest guidance appeared to slow the onset of this
potential by about an hour or so. But also, the guidance continues
to suggest widespread fog and potential LIFR stratus near FAY and
RWI early Friday morning. The worse case scenario ensemble shows
patchy fog near RDU, but confidence remains too low to include
restrictions there at the moment. The latest forecast is largely
unchanged, with just a minor tweak on timing and cessation of
stratus and fog at FAY/RWI, focused on the 09-13z period. VFR should
prevail at all sites the rest of the day Friday, with winds SSW.

Outlook: Widespread rain and associated sub-VFR conditions are
expected across the entire region from Saturday into Sunday night. A
cold front will sweep across the area on Monday, bringing a return
to dry weather and VFR conditions for early next week.

&&

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

&&

$$

DISCUSSION...Danco/10/MWS
AVIATION...Kren/Danco