Flash Flood Warning 128, NWS Charleston, WV

AREA FORECAST DISCUSSION
National Weather Service Charleston WV
242 PM EDT Fri Jul 18 2025

.SYNOPSIS...
A tropical airmass remains over the region with several shortwaves
passing through. Locally heavy showers and storms over increasingly
compromised soils may lead to flash flooding.

&&

.NEAR TERM /THROUGH TONIGHT/...

The atmosphere is primed for convection this afternoon and
evening with an extremely moist airmass in place. In fact,
PWATs on the latest SPC MesoAnalysis page are around 2" along
the OH River with most of the region between 1.7" and 2.1".

As of this afternoon, surface heating/insolation has
effectively eroded most of the morning inhibition, allowing
scattered thunderstorms to develop just to the west of the CWA.
This area of convection will move into the region later this
afternoon and into the evening. This will increase the flash
flood threat where storms train over already saturated soils or
train for multiple hours in one location. Instantaneous rainfall
rates could easily exceed 5" inches per/hr with one hr totals
exceeding 1-2". Any locations that see more sustained training
or repeated storms could see localized bullseyes over the next
24hrs of 2-5". This could lead to localized considerable flash
flooding.

As for some of the stronger storms, localized damaging winds
will be possible from wet microbursts. Any wind threat should
wane into the overnight, but heavy rain will remain a threat.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
The active and humid pattern continues Saturday. Another
mid-level disturbance will provide forcing within the same
tropical airmass. The thermodynamic profile will be similar to
Friday, with afternoon MLCAPE reaching 1000-2000 J/kg. A slight
increase in deep-layer shear is anticipated, with shear values
potentially reaching 20-30 knots. This may allow for better-
organized multicell clusters and transient short line segments,
increasing the potential for isolated damaging wind gusts,
warranting another Marginal Risk for severe thunderstorms. The
primary threat, however, remains flash flooding due to efficient
rainfall processes in the moisture-laden environment. It is
becoming increasingly likely the mid shift will need to issue
another Flash Flood Watch for Saturday.

By Sunday, a cold front will begin to push into the region from
the northwest. The front will serve as a focus for convective
initiation. Ahead of the front, strong heating/insolation will
again generate modest instability, with MLCAPE values
between 1000-2000 J/kg. While deep-layer shear will remain
modest, sufficient instability and lift along the boundary
support a Marginal Risk for severe thunderstorms, with damaging
winds being the main concern. The front will clear the area from
northwest to south Sunday night, bringing an end to the
widespread precipitation threat.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
A notable pattern shift occurs early next week as the frontal
boundary pushes south of the area and high pressure builds in
from the north. This will introduce a drier and more stable
airmass on Monday, resulting in a marked decrease in
precipitation chances.

The dominant weather story for the remainder of the long term
will be building heat. A subtropical ridge is forecast to
strengthen and expand northward, promoting subsidence and a
steady warming trend. High temperatures, starting in the mid
80s on Monday, are forecast to climb into the low 90s by
Wednesday and Thursday. With dew points remaining sticky in the
upper 60s to low/mid 70s, afternoon heat indices will approach
the mid/upper 90s, with some locations possibly reaching 100
degrees.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
As of 146 PM Friday...
Iso/sct SHRA with Iso TSRA/+TSRA continuing regionally.
Additional showers/storms develop this afternoon into the
evening. Under heavier shower/storms brief IFR from CIGs/VSBYs
likely. With the stronger storms, gusts from variable directions
in excess of 40kts will be possible in addition to lightning.

While activity should decrease overnight, lingering
showers/storms are possible throughout the night. Continued
widespread MVFR from CIGs likely, with localized IFR from
VSBYs/CIGs overnight. FG will also be possible at all TAF sites.

Another round of storms expected tomorrow with similar impacts
to today.

FORECAST CONFIDENCE: MEDIUM

ALTERNATE SCENARIOS: Improvements from overnight fog may vary
from the forecast. Timing, locations and intensity of showers
and thunderstorms today/tonight could 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       19   20   21   22   23   00   01   02   03   04   05   06
EDT 1HRLY       15   16   17   18   19   20   21   22   23   00   01   02
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    M    M    L
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  H    H    H    H    M    H    H    H    H    H    H    L
PKB CONSISTENCY  M    H    H    M    M    H    H    H    M    L    L    M
CKB CONSISTENCY  H    H    M    H    H    H    H    H    H    M    L    L

AFTER 18Z SATURDAY...Brief periods of IFR conditions possible under
showers and thunderstorms, mainly during the afternoon and
evening hours, into next week. IFR or worse fog is also possible
during the overnights, especially where any heavy rain falls
the previous day or evening.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Flood Watch until 2 AM EDT Saturday for WVZ005>011-013>020-
     024>034-039-040-515>526.
OH...Flood Watch until 2 AM EDT Saturday for OHZ066-067-075-076-
     083>087.
KY...Flood Watch until 2 AM EDT Saturday for KYZ101>103-105.
VA...Flood Watch until 2 AM EDT Saturday for VAZ003-004.

&&

SYNOPSIS...JRM
NEAR TERM...JRM
SHORT TERM...JRM
LONG TERM...JRM
AVIATION...JRM

Preliminary Local Storm Report
National Weather Service Charleston WV
1144 AM EDT Fri Jul 18 2025

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

1130 AM     Flash Flood      1 WSW Clarksburg        39.28N 80.34W
07/18/2025                   Harrison           WV   Emergency Mngr

            A swift water rescue was reported on
            Washington Avenue in Clarksburg.

&&

Preliminary Local Storm Report
National Weather Service Charleston WV
1146 AM EDT Fri Jul 18 2025

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

1130 AM     Flash Flood      2 WSW Clarksburg        39.27N 80.37W
07/18/2025                   Harrison           WV   Emergency Mngr

            Water flooding the parking lot of a gas
            station.

&&