273
FXUS61 KRLX 262311
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
711 PM EDT Sat Sep 26 2026

.WHAT HAS CHANGED...
00Z aviation discussion updated.

154 PM Update... Adjusted afternoon dewpoints downward across
the area to account for a known high moist bias in central
guidance. Continued low forecast confidence for late next week.

&&

.KEY MESSAGES...
1.) Another cool night tonight with valley fog.

2.) Seasonably cool and dry conditions continue through Monday
night before southwesterly flow resumes Wednesday. Overall low
forecast confidence beyond Thursday.

&&

.DISCUSSION...
KEY MESSAGE 1...

High pressure centered to the northwest continues to maintain a
dry low-level airmass across the central Appalachians. Observed
12Z soundings from Wilmington OH and Pittsburgh PA demonstrate
very dry mid and upper levels with precipitable water values
under 0.35 inches.

Surface dewpoints this afternoon were reduced below standard
NBM central guidance, trending closer to HRRR and MOS solutions
in the mid 40s to lower 50s. Calmer winds and clear skies over
the lowlands will support strong nocturnal inversions, allowing
typical cold spots away from major rivers to drop into the lower
40s overnight. Conversely, higher terrain and eastern mountain
slopes will experience increasing mid-level cloud cover and
tighter surface pressure gradients associated with a
retrograding coastal low off the Mid-Atlantic coast. This added
cloud cover and light wind stirring will limit radiational
cooling across the Northeast Mountains, keeping ridgetop and
mountain cold spot low temperatures warmer than previous
nights, although couldn`t completely rule out some very patchy
frost in the best protected mountain valleys with any thin spots
in the clouds.

Clear skies and light surface winds this evening will once
again foster favorable conditions for radiational cooling and
river valley fog formation for most of the lowlands overnight.
Slight tightening of the pressure gradient and increasing clouds on
the western periphery of the offshore storm system may render
fog coverage somewhat less aggressive than on previous nights
closer to the higher terrain. Any valley fog lifts and
dissipates through 10 AM Sunday.

KEY MESSAGE 2...

A large, vertically stacked coastal low moving inland near the
Mid-Atlantic coast will maintain northwesterly flow aloft across
the area through Monday night. While the bulk of moisture and
dynamic lift remain well east of the region, moisture brushing
the higher terrain may squeeze out isolated light rain showers
or drizzle across the highest ridges of the Northeast Mountains
late Sunday into Sunday night, with measurable precipitation
remaining generally under 0.10 inches. Otherwise, quiet and dry
weather prevails through early next week.

By Tuesday night into Wednesday, upper-level ridging builds over
the eastern states as southwesterly flow resumes across the Ohio
Valley and Metro Valley. This wind shift will initiate a
distinct warming trend, pushing afternoon high temperatures into
the upper 70s and lower 80s for Wednesday and Thursday.

Overall pretty low confidence beyond Thursday with a substantial
spread of solutions regarding development of a southern stream
low Wednesday/Thursday in the lee of the southern Rockies and a
potentially more potent northern stream system early next week.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Fog is once again expected to form in the river valleys
tonight, resulting in MVFR or worse restrictions through the
early morning hours. Extent of development may, however, be
limited by cloud cover spreading into the area from the
northeast, as well as moderate flow just off the surface.
Confidence in development is lowest at EKN and CKB.

Restrictions will improve between 12-15Z, then VFR is expected
for the rest of the day.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z MONDAY...

FORECAST CONFIDENCE: Medium with fog.

ALTERNATE SCENARIOS: Timing and extent of fog may vary from the
forecast.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

UTC 1HRLY       21   22   23   00   01   02   03   04   05   06   07   08
EDT 1HRLY       17   18   19   20   21   22   23   00   01   02   03   04
CRW CONSISTENCY  H    H    M    H    H    H    H    H    H    H    L    L
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  M    M    M    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  M    M    M    H    H    H    H    H    H    M    L    L
PKB CONSISTENCY  H    H    M    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  H    M    M    H    H    H    H    H    H    H    H    H

AFTER 00Z MONDAY...
IFR conditions are possible in morning river valley fog through
Wednesday.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...None.
OH...None.
KY...None.
VA...None.

&&

$$

DISCUSSION...JP
AVIATION...20