910
FXUS61 KRLX 161446
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
1046 AM EDT Thu Jul 16 2026

.WHAT HAS CHANGED...
Have issued a SPS across much of the lowlands for heat indices
this afternoon and early evening in the 95 to 100 degree range.

As of 353 AM Thursday...

Heat indices will remain below 100 degrees today, with haze and
smoke lingering into Friday. The forecast involving heavy showers
and thunderstorms late Friday into the weekend remains on track
otherwise. Isolated episodes of significant flash flooding will be
possible Saturday afternoon and night, along with a risk for
damaging wind gusts.

An Air Quality Alert has been issued for the State of Ohio from 7 AM
EDT this morning to midnight tonight.

There is a GOES-19/East data outage that has affected all products,
with no estimated restoration time.

&&

.KEY MESSAGES...
1) Hazy and hot today, with smoke from distant wildfires also
possible through Friday afternoon; and a stray shower or
thunderstorm cannot be ruled out across the northern parts of the
forecast area this afternoon.

2) Chances for heavy showers and storms will arrive Friday afternoon
and last into Sunday, with isolated episodes of significant flash
flooding possible Saturday afternoon and night, along with a risk
for damaging wind gusts.

&&

.DISCUSSION...
KEY MESSAGE 1...

The 16/00Z upper air charts observed an elongated center of the
deamplifying subtropical ridge that stretched from the Upper Midwest
southeastward over the CWA and into the Mid-Atlantic region, and was
objectively analyzed at 596 dam. The remnants of its center are
forecast to continue rotating southeastward throughout the next 24
hours as the base of a shortwave trough over east-central Canada
eclipses the CWA. High-altitude smoke from wildfires in central
Canada will aid in offsetting the full effects of diabatic heating
from becoming realized, and high temperatures were lowered slightly
for this afternoon as a result. Dewpoints were also adjusted down a
couple of degrees to match observations from yesterday. As a result,
heat indices are forecast to remain below advisory-level; however,
it will still be toasty outside today, especially with the haze
layer descending towards the surface.

Additionally, slight chance PoPs have been added across southeastern
OH and into northern WV for this afternoon. The development of a
diffuse differential heating boundary along the southern edge of the
primary smoke plume ahead of the slow, southward-moving cold front
along the I-70 corridor may result in the formation of a narrow
field of congested cu, especially given the presence of haze serving
as a source for CCN along the pre-frontal mesoscale boundary. With
convective temperatures being reached, a stray shower or storm will
be possible across the aforementioned areas later this afternoon,
although convective vigor will be tempered by the the mid-level
subsidence layer(s) observed by the 16/00Z RAOBs from WFOs ILN and
PBZ. A brief downpour and occasional cloud-to-ground lightning will
be the primary hazards. The core of the smoke plume embedded within
the phased jetlets rounding the base of the amplifying trough will
translate southward towards the CWA Friday, thereby posing a higher
potential for smoke to be observed at the surface. Highs for Friday
afternoon will be similar today, with heat indices peaking in the
upper 90s. A couple of locales may reach heat indices of 100 degrees
Friday afternoon, but spatiotemporal limitations will preclude a
Heat Advisory. An Air Quality Alert has been issued for the State of
Ohio from 7 AM EDT this morning to midnight tonight.

KEY MESSAGE 2...

The potential for heavy showers and storms will increase throughout
the afternoon and evening hours Friday, with widespread rainfall
expected Saturday. By Friday afternoon, a large-scale cyclone will
be vertically-stacked over Newfoundland, with the phased jet stream
rounding its base becoming sharply cyclonic while accompanied by
several series of shortwave perturbations translating through the
trough. The core of the jetlet will remain north of the CWA, but
with steering flow over the CWA veering towards the west following
the collapse of the subtropical ridge, a plume of moisture from the
Gulf Basin will advect into the region late Friday. A reservoir of
strong-extreme thermal instability already exists over the region,
with the 16/00Z RAOBs from WFOs ILN, PBZ, and RNK sampling MUCAPE
values between 2,700-4,700 J/kg amidst equilibrium levels above 200
mb. Destabilization of the boundary-layer will commence during the
afternoon hours Friday as the mid-level theta surfaces saturate in
conjunction with gradual cooling aloft from the slightly negative
geopotential height tendencies. At the surface, the aforementioned
cold front previously oozing its way southward into the CWA will
have become quasi-stationary in a wavy, east-west-oriented manner
across the State of WV. As the leading edge of moist, isentropic
ascent overspreads the CWA from the west-southwest ahead of a subtle
shortwave perturbation ejecting over the Rust Belt, PoPs will
increase accordingly, with scattered, heavy showers and storms
forecast to move across portions of the CWA heading into Friday
night. Locally heavy rainfall is a certainty with storms during the
afternoon and nighttime hours Friday, but flow and shear throughout
the deep- and cloud-bearing layers will remain anemic. Therefore,
the potential for organized convection is low Friday despite the
presence of the quasi-stationary front.

A substantial shortwave trough embedded within the larger-scale,
meridional waveguide is forecast to dig into the Great Lakes region
Saturday morning, and eject into the Adirondack and Catskill
Mountains by Saturday night. The quasi-stationary front previously
draped across the CWA is expected to undergo warm-frontogenesis and
move poleward Saturday morning, with a backed, low-level jet, which
will be synoptically-driven, strengthening to 25-30 kt. Theta-e
advection will be strong, with PWATs approaching record high values
over the CWA, between 1.90-2.10", amidst MUCAPE values forecast to
be near or in excess of 3,000 J/kg area-wide. As stated in previous
forecasts, warm-cloud depths up to 16 kft AGL will facilitate very
efficient rain processes within a background environment supporting
semi-progressive, frontal-parallel storm motions. Corfidi vectors
are forecast to be slightly oblique to the mean wind, but will be
unfavorable for upwind propagation; however, the orientation of the
mean wind and downshear propagation vectors will galvanize training
convection Saturday afternoon and night. Excessive water-loading
within updrafts, coupled with tall, strong CAPE profiles; and weak,
mid-level mesocyclones stemming from a slight elongation to the
hodographs, will result in organized storms producing upper echelon
rain rates. The previous forecast mention of rain rates exceeding
2"/hr remains intact with this prognostication.

Therefore, at least isolated episodes of significant flash flooding
are forecast to occur Saturday afternoon and night, with very rapid
onset of flooding possible even in drier areas that have missed out
on recent heavy rainfall. Strong-to-severe-caliber wind gusts would
be common with organized storms, with small hail also possible as
wet-bulb zero heights lower to around 12-13 kft AGL heading into
Saturday evening. The potential for episodic heavy rainfall will
last into the first half of the day Sunday, with rain and storm
chances waning from north-to-south throughout the afternoon as the
base of the shortwave trough pivots over the Appalachians and the
attendant cold front sweeps through the region. Benign weather is
forecast Sunday night outside of any ongoing flooding, with more
active weather returning by the middle of next week.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
IFR or lower flight conditions are expected for all terminals except
KBKW through sunrise due to river valley fog. Improvements to VFR
are forecast to occur near 13Z, but may be as late as 14Z at EKN
based on observations from the previous morning. Haze is expected
again today, but VSBYs will remain VFR, with smoke possible INVOF
KCKB, KEKN, and KPKB. VSBY restrictions from smoke are less certain
at this time at those terminals. Otherwise, high-altitude CIGs from
the smoke layer will remain SCT-BKN through the TAF period, with
calm winds becoming west-northwesterly later this afternoon.

*GOES-19/East data outage continues until further notice, with
no estimated restoration time.

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

FORECAST CONFIDENCE: Low-medium for fog through sunrise, then
high into the afternoon. Low confidence in isolated storm
potential this afternoon for KCKB and KPKB otherwise.

ALTERNATE SCENARIOS: VSBYs from smoke may fall below VFR at
KCKB, KEKN, and KPKB this afternoon.

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       12   13   14   15   16   17   18   19   20   21   22   23
EDT 1HRLY       08   09   10   11   12   13   14   15   16   17   18   19
CRW CONSISTENCY  L    L    H    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  L    M    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  M    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  M    M    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 12Z FRIDAY...
VSBY restrictions from smoke will continue to be possible at KCKB,
KEKN, and KPKB through Friday afternoon. The potential for heavy
showers and thunderstorms then arrive Friday afternoon and evening,
with heavy rain chances lasting through the weekend. IFR or lower
will accompany storms due to heavy rain, in addition to strong
surface wind gusts with storms Saturday.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...None.
OH...Air Quality Alert until midnight EDT tonight for OHZ066-067-
     075-076-083>087.
KY...None.
VA...None.

&&

$$

DISCUSSION...GW/Sincavage
AVIATION...Sincavage