758
FXUS61 KRLX 171024
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
624 AM EDT Thu Sep 17 2026

.WHAT HAS CHANGED...
Have issued an SPS across much of the central/southern lowlands
to highlight heat indices in the mid 90s to 100 degrees this
afternoon into the early evening. In addition, updated 12Z
Aviation Discussion.

As of 359 AM Thursday...

Minor adjustments to shower and storm chances through the
weekend, but otherwise, the forecast remains on track.

&&

.KEY MESSAGES...
1) A meandering frontal boundary will provide daily shower and
storm chances into next week. Storms could be heavy at times,
with the main concerns being the potential for localized flash
flooding and isolated strong wind gusts.

2) Hot conditions continue today across the lowlands, albeit
not as widespread as yesterday. A bit of a reprieve occurs on
Friday, with a gradual warming trend for the weekend.

&&

.DISCUSSION...
KEY MESSAGE 1...

A quasi-stationary frontal boundary continues to meander north
of the region this morning across the northern Ohio Valley,
resulting in another mainly clear and quiet morning across the
forecast area, albeit 5-10 degrees warmer than that of
yesterday. A WSW to W low-level feed continues to funnel
warm/moist air from the Gulf into the area, pivoting around an
upper ridge centered to our southwest across the western
Tennessee Valley. This continued moisture return has
facilitated slightly more widespread river valley fog this
morning, once again primarily south of the Ohio River where BL
flow is weaker. A gradual expansion in coverage may continue to
occur until dawn, with dense fog possible in the usual areas.

The aforementioned frontal boundary will begin to creep
southward today as a cold front, gradually crossing through the
CWA beginning tonight through midday on Friday. The front is
then progged to stall southwest of the area late Friday into
Saturday, then quickly buckle back north as a warm front late
Saturday and Saturday night, then once again become quasi-
stationary just north or across the forecast area into early
next week. This all translates into a generally active pattern
across the CWA, with daily rain chances amid warm/humid
conditions, into at least early next week. The primary concerns
with this pattern will continue to be the potential for
localized flash flooding and isolated strong diurnal storms at
times. A more robust shortwave may eventually help clear the
area out from showers/storms sometime mid to late next week.

Rain chances will be highly correlated to the position of the
frontal boundary, and enhanced by diurnal heating or at times
weak crossing upper-level perturbations atop the aforementioned
ridge. Given the overall recent wet pattern we`ve been in over
the last week or two, and the return of a very moist (Gulf
influenced) airmass with progged PWATs pushing 1.7-2.1" at
times (00Z ILN RAOB - 2.04"), the concern for flash flooding
will return. The period of greatest concern in the near term is
later today into tonight with the potential for heavy shower
and thunderstorm activity via diurnal heating and a weak
crossing upper wave. One hour FFG remains relatively low across
most northern zones at less than 1.5", with just slightly
higher values further south. CAMs however continue to depict
significant spread in progged rainfall amounts, with confidence
in placement of any heavier rainfall corridors remaining
relatively low. For example, 00Z HREF probabilities of 1.5"/hr
in a 25-mile radius are generally less than 10%. While this
doesn`t rule out the potential for isolated instances of flash
flooding today/tonight, it does result in confidence that is
too low for a Flood Watch at this time. WPC has maintained a
Marginal Risk for excessive rainfall across much of the area
today into tonight. A general reprieve is expected on Friday,
with isolated to scattered shower/storm chances across the south
and mountains. A mainly dry day is expected on Saturday, with
increasing shower/storm chances Saturday night through Sunday as
the front lifts back north across the area, with localized
flash flooding once again being possible.

The other aspect of this pattern will be the potential for
isolated strong diurnal thunderstorms at times, once again
hinging on the position of the frontal boundary. The general
setup will feature modest shear (15-25 kts / 0-6km) and modest
buoyancy (750-1,500 Mixed-layer CAPE) amid rather saturated
profiles. A few isolated strong storms remain possible this
afternoon/evening, main hazard being strong wind gusts via wet
downbursts. Additional strong diurnal storm potential could
return Sunday or early next week given slightly more favorable
progged kinematics, but will once again hinge on the front`s
position in relation to the CWA.

KEY MESSAGE 2...

Oppressive heat and humidity will continue today across portions
of the area in advance of the aforementioned cold front across
the northern Ohio Valley. Increased cloud cover and rain chances
this afternoon/evening will temper the overall coverage of
oppressive conditions across the lowlands from that of
yesterday, existing today more so across our central/southern
zones, where highs will once again reach the upper 80s to low
90s, while mid 80s are expected across the northern lowlands.
Have once again lowered dew points from central guidance this
afternoon/evening, generally expecting values in the low 70s.
The combination of aforementioned temperatures and dew points
will result in heat indices this afternoon and early evening
reaching the mid 90s to 100 across the central/southern
lowlands, with an SPS potentially being issued later to
highlight this. Be sure to take frequent breaks if outside
during peak heating hours today.

Some relief is expected on Friday as the aforementioned cold
front gradually slides south through the area, bringing a
return to near seasonable values - low/mid 80s across the
lowlands. Warmer and more humid conditions, albeit not as bad
as today, return over the weekend as the front buckles back
north of the CWA. Highs are progged for the mid 80s to near 90
across the lowlands.

&&

.AVIATION /10Z THURSDAY THROUGH MONDAY/...
River valley fog will lift / scatter out from ~ 1130-1300Z this
morning. Mainly VFR conditions are then expected during the day
today amid a FEW/SCT (030-050) Cu field late morning through
the afternoon in some areas. ISOLD to SCT showers/storms are
expected as we go through the day, primarily north, bringing
the potential for brief MVFR/IFR VSBY restrictions. Confidence
in timing/placement remains low. Given such, have just coded
PROB30 groups into the TAFs for the time being during the
afternoon into early tonight. SCT showers/storms are expected
to continue overnight as a cold front gradually moves southward,
bringing the potential for additional restrictions. In addition,
some valley fog development is possible towards 6Z and onward,
along with the development of lower stratus. Confidence in
either remains lower, but some restrictions are likely at most
terminals by late tonight.

Light flow is expected today, generally ranging from WSW to NW,
with flow going calm at most sites tonight.

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

FORECAST CONFIDENCE: Medium today, low tonight.

ALTERNATE SCENARIOS: Timing and location of showers and
thunderstorms today into tonight will vary from the forecast,
with brief MVFR/IFR restrictions possible within showers/storms.
Restrictions with fog and/or stratus tonight will likely 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       10   11   12   13   14   15   16   17   18   19   20   21
EDT 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
CRW CONSISTENCY  L    L    L    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  L    L    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  M    M    M    L    H    H    H    H    H    H    H    H
PKB CONSISTENCY  L    L    L    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  L    H    H    H    H    H    H    H    H    H    H    H

AFTER 12Z FRIDAY...
Patchy IFR conditions are possible with river valley fog and/or
stratus each morning through the weekend, most likely in and
near the higher terrain. Brief IFR conditions could also occur
at times into early next week within showers/storms.

&&

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

&&

$$

DISCUSSION...GW
AVIATION...GW