478
FXUS62 KRAH 181701
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
100 PM EDT Sat Oct 18 2025

.SYNOPSIS...
High pressure will remain offshore through tonight. A cold front
will cross the region Sunday night, followed by high pressure
settling back into the area Monday and Tuesday. A dry cold front
will cross the region on Wednesday, with cool high pressure settling
in late next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 100 PM Saturday...

* Quiet weather through tonight

High pressure shifts offshore tonight, ahead of a cold front moving
into the TN/OH valley early Sun as an area of low pressure tracks
into the lower Great Lakes. Southerly winds will remain stirred
tonight around 5-10 mph, keeping temperatures mild in the mid to
upper 50s, except some lower 50s over the Coastal Plain where winds
may decouple. Middle and high clouds will be on the increase
overnight, especially across the west, ahead of a vigorous upper
trough that will reach the MS/TN valley region Sun morning.


&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
As of 100 PM Saturday...

* A band of showers with embedded isolated thunder will move through
  during the early to late evening hours, capable of producing
  strong to locally damaging wind gusts

* Gradient winds of 25-25 mph are expected during the day outside of
  showers

* Post cold frontal gusts of 30-35 mph will be possible, diminishing
  by early Mon morning

A vigorous upper trough will track through the region Sunday evening
and Sunday night. The center of the shortwave will track from the
lower OH/TN valley region into the southern Appalachians and
portions of north-central NC and central VA before reaching the
northern Mid-Atlantic by Mon morning. Impressive height falls of 80-
150 dm will accompany the trough, along with an anomalous upper jet
streak of 90-100 kt SW to NE.

At the surface, a strong cold front is forecast to move through from
west to east during the late evening to early overnight hours as low
pressure tracks into Canada.

As we have been advertising for the past several days, a tight
pressure gradient coupled to strong winds in the 925-850 mb layer of
30-45 kt will promote gradient winds of 25 to 35 mph during the
afternoon and early evening hours. These winds should be below wind
advisory criteria, but we will have to monitor showers capable of
producing strong to locally damaging gusts, as we will discuss next.
Highs should top out in the mid to upper 70s, with a few spots near
80. The one exception will be over the NW Piedmont, with highs in
the low 70s due to cloud cover and some pre-frontal showers.

For shower chances along and ahead of the front, nearly all ensemble
data, including several CAM members, show measurable precipitation
over most of central NC, with highest amounts in the NW Piedmont
closer to the shortwave trough and deeper forcing. Amounts range
from about a quarter of an inch in the NW, around a tenth of an inch
in the Triangle, and a tenth of an inch or less over the Sandhills
and southern Coastal Plain. PW values are near 180-percent of normal
around 1.5 inches.

A weak area of pre-frontal showers may move through over the
Piedmont during the late afternoon to early evening hours, but is
expected to be weak in nature. The more potentially impactful period
will be just immediately ahead of the cold front, when a band of
showers with embedded isolated thunder will track east-northeast.
Timing for this looks to be during the mid-evening (6-9p) in the
Triad to late evening in the Triangle (9p-12a) and early overnight
hours in the Coastal Plain, though could be a tad earlier or later
given some HREF model spread. SPC has introduced a marginal risk of
damaging wind gusts mainly along/north of US-64, in line with
several AI severe diagnostics. This appears to be mainly driven by
very impressive low to deep-layer shear, with 20 kt of 0-1 km shear,
40 kt of 0-3 km shear, and 50-60 kt of 0-6 km shear. Instability
remains the limiting factor, with guidance suggesting a stripe of
250-500 J/kg of CAPE along the front. Even in the absence of
instability, the strong forcing and increasing LLJ of 50 kt at 850
mb should favor some gusts mixing down to the surface via the
showers. This has been suggested by the last few runs of the HRRR,
where 35-45+ kts are possible along the frontal line.

Scattered showers should exit all of central NC by the early
overnight hours, though post-frontal CAA gusts of 30-35 mph will
still be possible. Lows will be cooler in the mid 40s NW to low 50s
SE.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
As of 100 PM Saturday...

* Another mostly dry front will keep the region seasonably cool.

By Monday morning, the cold front will be out over the Atlantic
Ocean with high pressure centered over the southeastern United
States. The influence of the high will be relatively short-lived as
low pressure will race across the United States-Canadian border
during the first half of the week, bringing a second cold front
through the area Tuesday evening. It`s hard to find a deterministic
model showing any precipitation with the Tuesday front - the 00Z
European shows rain limited to the North Carolina coastline.
Meanwhile, the European ensemble does hint at the possibility of
showers primarily north and east of Raleigh. The current forecast
have the chance of rain as less than 10 percent. Once the next front
pushes offshore, another high pressure system will move across the
southeastern US, and this should persist into the weekend.

Normal temperatures for late October are low 70s and high 40s. While
Tuesday should have highs a few degrees above normal, the rest of
the extended forecast should have highs slightly below normal.
Similarly, Tuesday night`s lows should be slightly above normal,
with the rest of the extended forecast slightly cooler than normal.

&&

.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...
As of 100 PM Saturday...

VFR conditions with light southwesterly winds through this evening
then becoming southerly overnight into Sunday morning. Winds are
expected to pick up ahead of the cold front mid morning Sunday with
gutsy winds of 20-30kts through the 18z TAF period. The main weather
restrictions will come after 18z Sun, thus did not introduce any
flight restrictions with this 18z/Sat TAF.

Outlook: Ahead of an approaching cold front, southwesterly winds
will increase with gusts to 25-35 kts beginning Sunday afternoon. A
band of low VFR to MVFR ceilings and showers will likely accompany
the front. VFR conditions will return on Monday and continue
through midweek, with breezy conditions again possible Tuesday and
Wednesday.
&&

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

&&

$$

SYNOPSIS...AK
NEAR TERM...AK
SHORT TERM...AK
LONG TERM...Green
AVIATION...CA/BLS