107
FXUS61 KRLX 272341
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
741 PM EDT Mon Jul 27 2026

.WHAT HAS CHANGED...
Updated 00Z Aviation Discussion.

&&

.KEY MESSAGES...
1) Rounds of fast-moving showers and thunderstorms are forecast to
move through the region late tonight into Tuesday afternoon.

2) Chances for showers and storms linger in the mountains Wednesday,
with drier weather to follow into Friday ahead of additional storm
chances this weekend.

&&

.DISCUSSION...
KEY MESSAGE 1...

18Z upper air analysis depicts a well-defined cyclone rotating over
the Hudson Bay, along with a subtropical ridge, objectively analyzed
at 598 dam, centered in the southern High Plains. The subtropical
ridge encompasses the western half of the U.S., while more-sharply
cyclonic flow is present over the region and northeastward into New
England. An anticyclonically-curved jet streak, also objectively
analyzed at nearly 100 kt, arcs around the apex of the subtropical
ridge before approaching the inflection point of large-scale cyclone
over far northeastern Canada, with its exit-region advecting over
the CWA. The respective jetlets of these two synoptic features are
not phased; however, an intense, shortwave perturbation is embedded
within the leading edge of the anticyclonically-curved jet streak
branching southeastward over the Great Lakes, where an organized MCS
is ongoing across portions of Lake Michigan. This MCS will have
implications to the forecast across the CWA late tonight into
Tuesday morning and afternoon.

At the surface, a weak anticyclone was located in the vicinity of
the Coal Fields in eastern KY, with a warm front progressing
eastward towards the I-69 corridor. Winds were calm and variable,
but are expected to transition towards the southwest this evening
into the nighttime hours while becoming breezy as the warm front
moves eastward across the region. Southwesterly winds between 10-15
mph, with gusts up to 20 mph, will be common area-wide by sunrise
Tuesday due to the large-scale pressure falls associated with the
system emerging over the CWA late tonight. The low stratus deck
draped across the CWA earlier this morning has since transitioned
into a shallow cu field, but large-scale subsidence (capping) will
preclude any development of showers or thunderstorms for the rest of
the afternoon across the CWA.

The potential for showers and storms will begin to increase late
tonight, with the eastern edge of the aforementioned MCS forecast to
clip the western portions of the CWA across KY, far southeastern OH,
and far southwestern WV. Forward-propagation of this MCS is already
underway, and upshear and downshear Corfidi vectors are aligned
slightly to the right of the mean wind, with enlarged magnitudes at
around 25 kt and 55 kt, respectively. The main core of the MCS is
forecast to nosedive southward along the thickness gradient and miss
the CWA with respect to the bulk of severe-caliber storms; however,
a couple of strong gusts in excess of 40 mph and heavy rainfall will
be possible as it clips the western zones late tonight. Weakening of
the MCS will also be attributed to diabatic stabilization of the
airmass and the eventual forward-surging of outflow from the leading
edge of convection, with an expectation for a quick progression as a
more-substantial shortwave trough splitting off from the cyclone
wobbling over the Hudson Bay trails behind while digging into the
Great Lakes. That said, remnant outflow boundaries may propagate
into the CWA ahead of the secondary shortwave trough digging
southeastward towards the region during the predawn hours Tuesday.

Vigorous and moist, isentropic ascent will overspread the CWA ahead
of this shortwave trough, with widespread showers and storms
forecast to evolve and advect towards the southeast across the CWA
prior to and after sunrise. The mean convective movement associated
with the mid-to-late-morning clusters of storms will be governed
largely by advection, as the core(s) of the 250 mb and 500 mb jet
streaks, at or around 90 kt and 50 kt, respectively, translate over
the CWA amidst an unfavorable alignment of the shear vectors to
allow for upwind propagation. The remnant outflow(s) may serve as a
foci for localized enhancements to the cellular clusters, especially
given the vigor of moist, isentropic ascent as the synoptic cold
front moves in from the northwest. Efficient rainfall is expected
due to warm-cloud depths of 15-16 kft AGL and wet-bulb zero heights
above 14 kft. Therefore, swaths of heavy rainfall are a certainty
with the mid-to-late-morning episode of convection, but the
progressive, southeastward movement is forecast to keep the flash
flooding potential localized due to the magnitude of the mean wind
vectors approaching 40 kt. A few strong wind gusts in the 30-40 mph
range cannot be ruled out near and after sunrise Tuesday, but the
columns should otherwise be too moist to warrant the production of
strong, convective wind gusts.

Storm chances heading into Tuesday afternoon following this
secondary convective episode remain less certain. It appears that at
least isolated-to-widely-scattered, elevated showers and storms will
be possible as a smaller-scale, closed cyclone forms within the
shortwave trough digging into NY. Northwesterly flow will maximize
the cross-barrier component relative to the Appalachian Mountains,
maintaining orographically-induced showers and storms into late
Tuesday night across the mountains. Otherwise, storm chances will
wane from northwest-to-southeast across the CWA by late Tuesday
afternoon, with dry breeze from the northwest at 10-15 mph and
temperatures a few degrees cooler than today.

KEY MESSAGE 2...

The shortwave trough digging into NY will continue to meander over
the megalopolis Wednesday while remaining closed. A large-scale
blocking pattern is forecast to evolve as the subtropical high
expands and retrogrades slightly westward, and as the Bermuda High
over the North Atlantic amplifies. The jetlets rounding the base of
this shortwave will dampen in intensity, but with northwesterly flow
being maintained along with some corridors of PVA, prospects for
showers and a few storms continue to be forecast for locales along
the spine of the Appalachian Mountains overnight Tuesday and into
Wednesday afternoon. Severe weather nor flash flooding are expected
across those areas Wednesday. The shortwave trough is forecast to
pivot eastward slightly by the latter half of the week, yielding
high-level convergence aloft and keeping the CWA dry, with chances
for showers and storms returning late this weekend.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...

VFR conditions are currently seen areawide. Showers and
thunderstorms will approach from northwest to southeast between
06Z and 09Z Tuesday. This will bring MVFR and IFR ceiling
reductions. In addition, any thunderstorm can bring heavy
downpours and associated IFR/LIFR visibility reductions.
Ceilings should improve between 15Z to 18Z Tuesday.

Winds will be predominantly from the southwest overnight and
Tuesday morning. A cold front will shift the winds to a
northwesterly direction between 18Z Tuesday and 00Z Wednesday.

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

FORECAST CONFIDENCE: Medium.

ALTERNATE SCENARIOS: Thunderstorms and associated visibility
reductions can 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    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 00Z WEDNESDAY...
Lingering -SHRA/-TSRA will be possible at some of the terminals
Tuesday afternoon and would be accompanied by IFR conditions,
before clearing prior to dusk Tuesday. IFR conditions will
continue to be possible with valley fog each morning Wednesday
through Friday across the region.

&&

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

&&

$$

DISCUSSION...Sincavage
AVIATION...26