615
FXUS61 KRLX 201841
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
241 PM EDT Mon Jul 20 2026

.WHAT HAS CHANGED...
The forecast involving the potential for severe thunderstorms
Tuesday afternoon and evening remains on track, although there is
some uncertainty with the total coverage and extent of severe
storms. A few showers and thunderstorms may develop across the
mountains this afternoon and tonight as well.

&&

.KEY MESSAGES...
1) A few showers and thunderstorms may develop across the mountains
this afternoon and tonight, with hazy conditions otherwise.

2) Widespread showers and storms are forecast area-wide Tuesday
afternoon and night, some of which may be severe and capable of
producing damaging winds, hail, a tornado or two, and heavy rain.

3) Drier and milder weather is forecast Wednesday through Friday,
with additional storm chances arriving this weekend.

&&

.DISCUSSION...
KEY MESSAGE 1...

In the mid/upper-levels, an amplifying subtropical ridge was
centered over the central Rocky Mountains, with a well-defined
shortwave trough pivoting across south-central Canada and into
western Ontario. A closed, mid-level low was embedded within this
shortwave trough, the latter of which is on the western periphery of
a larger-scale belt of cyclonic, gyre-like flow over northeastern
Canada. The exit-region to the anticyclonic jet streak arcing over
the center of the subtropical ridge was overspreading the region,
with anvil debris/mare`s tails advecting towards the western
portions of the CWA. As such, large-scale subsidence will result
keep the bubbling cu field suppressed this afternoon, with the
exception of the mountains due to the typical orographic effects.

At the surface, a warm front was nearly stalled to the south of the
CWA along the NC/TN/VA border, with WAA-induced showers ongoing
along the spine of the Cumberland Mountains in far western VA and
into far southern Coal Fields. This warm front will continue to
sharpen in baroclinity while advecting poleward over the next 24
hours in response to the large-scale pressure falls associated with
the aforementioned shortwave trough digging into the Great Lakes
region by dawn Tuesday. Widely-scattered showers and storms may
develop across the mountainous terrain for the remainder of the
afternoon hours, as the warm front will be slow to advect poleward
until later tonight. Severe weather is not expected this afternoon;
however, highly localized flash flooding will be possible given the
meager CAPE profiles of <=1,075 J/kg (per 12Z RAOB from WFO RNK) and
PWATs between 1.00-1.25". Otherwise, muggy conditions are expected
area-wide for the rest of today beneath a high-altitude smoke plume,
the latter of which may result in some reductions to visibility,
primarily across the northern portions of the CWA.

As the warm front continues to lift poleward during overnight hours,
WAA-induced showers and perhaps a couple of storms may develop along
the leading edge of the front. Convective organization will be
greatly tempered, with cells progressing northeastward in tandem
with the warm front. Brief downpours will be possible, with PoPs
maintained across the mountainous terrain across WV southwestward
into far western VA. It is possible that showers linger into sunrise
across those locales as the leading wave of shortwave perturbations
begin to eject over the CWA. Severe weather is not expected tonight.

KEY MESSAGE 2...

Widespread showers and storms are forecast area-wide Tuesday, as the
shortwave trough currently digging into western Ontario begins to
eject over the Great Lakes while becoming open. The opening of the
closed low will be induced by another more-subtle shortwave trough
digging south-southeastward over the Hudson Bay, which will act to
maintain the progressiveness of the mean troughing. Geopotential
height falls on the order of about 30 m/12 hr will contribute to a
net increase in thermal instability, with CAPE values ranging
between 1,500-2,500 J/kg, depending on parcel trajectory. The 12Z
RAOB from INL this past morning sampled the elevated mixed layer
advecting eastward towards the region, with MUCAPE of 2,252 J/kg,
which bolsters confidence in the handling of the EML by forecast
soundings. A decaying MCS generated during the previous night is
forecast to propagate across the Rust Belt and into southeastern OH
by daybreak Tuesday, which may result in substantial convective
overturning of the airmass as its remnants propagate across the CWA
through the late morning hours. Thick anvil debris and intermittent
heavy showers may inhibit the vigor of convection by the afternoon,
as successful recovery of the airmass is uncertain despite effective
and cloud-layer shear magnitudes increasing to 50 kt and 60 kt,
respectively. However, areas that are not affected by the remnant
MCS for a prolonged period of time will have the greatest potential
for airmass recovery, and there is particular interest across the
southwestern zones where this may come to fruition.

Differential diabatic heating through cloud breaks amidst moderate
return flow will aid in boosting temperatures into the upper 80s,
contributing to a strongly unstable boundary-layer by the afternoon
hours as dewpoints hold steady in the lower-middle 70s. As the
synoptic cold front approaches from the northwest and convective
temperatures are reached, rapid storm development will be possible
across the Coal Fields of northeastern KY and into southwestern WV,
with storms forecast to unzip into another MCS that should become
organized quickly due to the magnitude of large-scale forcing for
ascent. Corfidi vectors favor upshear propagation of cellular
development as the cold pool(s) of the MCS establish, with MCS
propagation oriented towards the south-southwest along the edge of
the thickness gradient. How far north and west into southeastern OH
and/or western WV organized MCS development occurs is less certain;
however, numerous swaths of strong-to-severe-caliber gusts between
50-60 mph will be common, with more-isolated gusts approaching 70
mph becoming a possibility. A line-embedded tornado threat may
accompany the MCS as well, and it is appearing less apparent that a
supercell tornado threat will develop within the boundaries of the
CWA. Wet-bulb zero heights between 14-15 kft AGL would act to temper
the hail risk, but a few instances of large hail near quarter size
will certainly be possible given the magnitude of the deep-layer
shear and wider updrafts. Torrential rainfall will be common with
any severe storm(s) Tuesday afternoon and evening, but a significant
flash flooding risk will be kept in check due to the progressive
movement of individual and/or line segments. Therefore, a Flood
Watch will not be issued with this afternoon package. A second round
of showers and storms may affect portions of the CWA heading into
Tuesday evening, but convection should be elevated and weaker as
thermal instability depletes, and as the boundary-layer decouples.

KEY MESSAGE 3...

Valley fog is forecast to return area-wide Wednesday morning
following the episode of severe storms, with additional bouts of
valley fog each morning through Friday. Drier and milder weather
forecast during the afternoons, as the heavily modified cP airmass
trailing the secondary cold front passage Wednesday morning settles
into the region. The CWA will be bereft of PoPs through at least
Friday, with the exception of the mountains come Friday afternoon,
as global NWP guidance continues to indicate a shortwave impulse
propagating through a broader belt of cyclonic flow. Additional
storm chances are then forecast to arrive this weekend, but details
involving coverage and timing remain nebulous.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
Some brief reductions to VSBY from smoke and haze may occur at a few
of the terminals through sunset, but VSBYs are forecast to remain at
or above 6SM. Isolated -SHRA/-TSRA will be possible INVOF KBKW and
possibly KEKN this afternoon, but the mention of TSTMs has been
withheld from KEKN due to lower confidence. MVFR CIGs/VSBYs are then
forecast to return to KCRW, KBKW, KEKN, and KPKB tonight, with -SHRA
also possible at those terminals during the predawn hours. IFR
conditions are forecast at KEKN tonight. Valley fog that develops
during the predawn hours Tuesday will dissipate after sunrise, with
a return to VFR overcast and a southwesterly breeze increasing to
around 10 kt at all terminals.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...

FORECAST CONFIDENCE: High through this evening, then medium for
fog and ceiling potential Tuesday morning.

ALTERNATE SCENARIOS: Impacts due to haze and smoke this afternoon and
evening could be worse than forecast. MVFR CIGs Tuesday morning may
affect more terminals than 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       18   19   20   21   22   23   00   01   02   03   04   05
EDT 1HRLY       14   15   16   17   18   19   20   21   22   23   00   01
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
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    H    H    H    H    H    H    H    H
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 18Z TUESDAY...
IFR/LIFR is likely in heavy showers and thunderstorms Tuesday
afternoon, some of which may be severe.

IFR or lower is forecast Wednesday morning due to valley fog, with
similar conditions each morning through Friday.

&&

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

&&

$$

DISCUSSION...Sincavage
AVIATION...Sincavage