843
FXUS62 KRAH 011839
AFDRAH

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

.WHAT HAS CHANGED...

* Confidence is increasing that a wave of low pressure will track
  along a quasi-stationary front over the Carolinas and regionally
  enhance rainfall intensity and amounts Saturday night and Sunday.

&&

.KEY MESSAGES...
As of 300 AM Thursday...

1) Patchy dense fog and low clouds will reduce visibilities early
this morning across portions of central NC, with the lowest
visibilities and most persistent fog focused across the Sandhills
and Coastal Plain.

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

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

&&

.DISCUSSION...
As of 300 AM Thursday...

KEY MESSAGE 1... Patchy dense fog and low clouds will reduce
visibilities early this morning across portions of central NC, with
the lowest visibilities and most persistent fog focused across the
Sandhills and Coastal Plain.

Calm winds and high low level moisture early this morning will help
fog and low cloud development through daybreak. While patchy fog is
possible farther west in the Piedmont, the thickest fog and lowest
cloud cover will develop across the Sandhills and Coastal Plain.
Visibilities could drop to a quarter mile or less at times during
the morning commute, especially along and east of US1 creating
localized pockets of dense fog. Morning sunlight will quickly burn
off the fog, returning mostly clear skies/high clouds to the region
by mid morning.

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

A sub-tropical high, centered over GA in 700-500 mb upr air data at
00Z/1st and with observed heights around the 90th percentile at GSO,
will progress offshore today and settle across the swrn N. 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
wwd across the Southeast, through Fri. Subsidence from the
subtropical ridge aloft, and sly, "return" flow around the Bermuda
surface high, will contribute to additional warming of the airmass
over the Carolinas and a couple more days of summerlike
temperatures. While hotter by day, and gradually more humid/muggy by
night, afternoon humidity levels will remain relatively low and in
the 30s to 40s percent courtesy of mixed/afternoon dewpoints that
will again decrease mostly into the mid-upr 50s this afternoon and
low-mid 60s F Fri afternoon.

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

A positively-tilted srn stream trough/shear axis will 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. The models have trended slower and more amplified with
one of those shortwave troughs forecast to dig from the nrn Rockies
to the OH Valley through the weekend and which will likely favor a
period of enhanced lift over cntl NC Sat night-early Sun night.

At the surface, high pressure extending from near Bermuda to the
South Atlantic coast will be displaced by a wavy frontal zone
forecast to settle swd and across cntl NC on Sat, then stall and
become quasi-stationary from SC to southeastern NC Saturday night. A
following, ~1028-1030 mb cP high will progress across and offshore
sern Canada this weekend, while extending swd across the Middle
Atlantic and Carolinas. Though progressive, the high will be
favorably strong and located for cold air damming to develop over
the srn Middle Atlantic and Carolinas. The associated wedge front
may buckle nwd across ern NC with the passage of a weak frontal wave
Sun into early Sun night.

Initially patchy and light rain, in the developing damming regime
and nely flow on Sat, will become steadier and increase in intensity
Saturday night and Sunday. It will do so as mass response, ahead of
the aforementioned nrn stream shortwave trough that has trended more
amplified in model guidance during the past 24 hours, accelerates
the flow and strengthens isentropic upglide across the frontal zone
and atop the CAD high. Although there remains uncertainty in storm
total rainfall amounts, it appears increasingly likely that a
relatively widespread, soaking rain will result over cntl NC by the
end of the weekend. As confidence in that pattern (probably)
continues to increase in the coming days, forecast high temperatures
and diurnal ranges for Sat night-Sun night will probably require
additional adjustments downward from currently forecast NBM/WPC
ones. In fact, if the previously noted pattern indeed occurs,
temperatures on Sun will likely be very similar to the distribution
of 60s F that occurred in the recent cold air damming episode of
9/23.

A reinforcing cold front and following cP/Canadian surface high will
progress across the srn Middle Atlantic early next week, with
following cool and dry fall conditions for cntl NC through at least
mid week.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
As of 230 PM Thursday...

24 hour TAF period: VFR conditions will prevail across central NC
through this evening. Model guidance is in pretty good agreement
that areas of fog/mist will develop over the Coastal Plain and
eastern Sandhills (including FAY and RWI) late tonight after 07z,
lasting into early Friday morning. MVFR/IFR visibilities are likely,
and isolated LIFR visibilities can`t be ruled out. Also can`t rule
out patchy IFR/LIFR ceilings from very low stratus. The other TAF
sites should stay VFR, and VFR will return everywhere by mid-
morning. Winds will stay fairly light (less than 10 kts) and from
the SW through the period, going calm in many spots tonight.

Outlook: VFR conditions and dry weather will hold through Friday
night. 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...CA/MWS
AVIATION...Danco