Flash Flood Warning 251, NWS Charleston, WV

Area Forecast Discussion
National Weather Service Charleston WV
531 AM EDT Wed Sep 23 2026

.WHAT HAS CHANGED...
Updated 12Z aviation discussion. Model output continues to vary
substantially regarding placement of convective precipitation
through the day today into this evening, but the general theme
of the heaviest rainfall remaining south and west of out
forecast area continues.

As of 306 AM Wednesday...

Trimmed and realigned the Flash Flood Watch to match where
slow-moving rain aligns with suppressed flash flood guidance for
through this evening.

&&

.KEY MESSAGES...
1.) Localized flash flooding threat from slow-moving showers
and thunderstorms continues through this evening, primarily
across the southern coalfields.

2.) Transition to dry, seasonable autumn weather Thursday
through the weekend as cooler air advects from eastern Canada,
bringing daytime highs in the 70s and crisp nighttime lows in
the 40s and 50s.

&&

.DISCUSSION...
KEY MESSAGE 1...

A weak upper-level cold-core low will drift slowly southward
across the Ohio Valley today into the Tennessee Valley tonight.
Strongest synoptic forcing for ascent remains focused generally
south and west of the forecast area. Precipitable water values
across the region fall in the 1.3 to 1.5 inch range, with warm
cloud depths only around 5000 ft and equilibrium levels around
25 to 30kft with long skinny elevated CAPE profiles. This
general mix of positive/negative factors for efficient rainfall
production should help to limit convective rates to around half
to perhaps one inch per hour rates in the strongest updrafts.

However, steering flow remains exceptionally weak, yielding very
slow cell motions around 5 to 10 mph. Convection that does
develop will be capable of persisting over localized areas for
several hours, potentially overcoming suppressed 3-hour flash
flood guidance from antecedent rainfall. The Flash Flash Flood
Watch has been trimmed and realigned to focus on areas across
the southern coalfield where several hours of moderate to heavy
rainfall could coincide with sensitive soils. While 3-hour
flash flood guidance portions of southeast Ohio is even more
suppressed, marginally over 1 inch, overall confidence in
convective coverage remains too low to warrant an expansion into
that area at this time.

KEY MESSAGE 2...

As the upper low weakens and opens into a wave while moving
eastward on Thursday, lingering shower coverage over the
mountains will gradually diminish from north to south. Surface
high pressure building over Quebec and a deepening coastal low
off the Atlantic coast will continue a persistent northeasterly
flow across the region. This flow regime will continue to advect
a much drier continental airmass from eastern Canada into the
area Thursday through the weekend.

Dewpoints will crash into the 40s by Friday afternoon, with
relative humidity values dropping noticeably. High temperatures
Friday through Monday will range comfortably in the lower to mid
70s across the lowlands and 60s in the Northeast Mountains. With
clear skies and light winds under high pressure, optimal
radiational cooling and cold air drainage will occur Friday
night and Saturday night. Overnight lows will drop into the
upper 30s to lower 40s in sheltered mountain valleys, and the
mid 40s to lower 50s across the lowlands. Could even see some
patchy frost in the mountain valleys Friday morning. This will
also likely yield valley fog each night.

Temperatures will begin a warming trend into the middle of next
week as southerly flow returns ahead of low pressure organizing
in the lee of the Rockies by Monday night.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
Will continue to see erosion from east to west of remaining any
remaining low IFR this morning. Expect renewed development of
stratocumulus by late morning, generally based 015-020. With an
inversion between 020-030 expect clouds bases to struggle to mix
above that layer through this afternoon.

Scattered to numerous showers are expected through this evening
with isolated thunderstorms this afternoon. Any convection will
be fairly slow moving and if it gets over a terminal may linger
for 30 to 45 minutes. Best chances at HTS this afternoon.

Winds generally northeasterly 5-10KTs, except southeasterly
downslope at EKN/BKW.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY...

FORECAST CONFIDENCE: Medium.

ALTERNATE SCENARIOS: Coverage of showers and thunderstorms may
vary through this evening.

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.

DATE               WED 09/23/26
UTC 1HRLY       09   10   11   12   13   14   15   16   17   18   19   20
EDT 1HRLY       05   06   07   08   09   10   11   12   13   14   15   16
CRW CONSISTENCY  L    L    M    L    M    M    H    H    H    H    H    H
HTS CONSISTENCY  L    L    L    M    L    L    H    H    H    H    H    H
BKW CONSISTENCY  M    H    H    M    M    H    H    H    H    H    H    H
EKN CONSISTENCY  M    M    M    H    H    H    H    H    H    H    M    H
PKB CONSISTENCY  H    H    M    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  M    M    M    H    H    H    H    L    H    H    H    H

AFTER 12Z THURSDAY...
IFR in morning valley fog each morning starting Friday.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Flood Watch through this evening for WVZ005-013-024>026-033-
     034-515-516.
OH...None.
KY...Flood Watch through this evening for KYZ105.
VA...Flood Watch through this evening for VAZ003-004.

&&

DISCUSSION...JP
AVIATION...JP

Preliminary Local Storm Report
National Weather Service Charleston WV
1215 PM EDT Wed Sep 23 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1210 PM     Flash Flood      10 W Buffalo            38.62N 82.17W
09/23/2026                   Mason              WV   911 Call Center

            Water over Huntington Road.

&&