Area Forecast Discussion
Issued by NWS Charleston, WV

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159
FXUS61 KRLX 120904
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
504 AM EDT Tue May 12 2026

.WHAT HAS CHANGED...
12Z Aviation Forecast Discussion update.

321 AM Update... Temperatures have dropped below freezing in
portions of the Freeze Warning area, and even in some valley
locations in the Frost Advisory area, early this morning.

&&

.KEY MESSAGES...
- 1) Freeze Warnings and Frost Advisories remain in effect
  until 8 AM this morning for frost and freeze conditions in the
  northern mountain valleys.

- 2) Showers and thunderstorms, the storms possibly strong,
  return with cold front on Wednesday.

- 3) Dry, with early morning frost possible in the mountains on
  Friday.

- 4) Trending much warmer this weekend into the next work week.

&&

.DISCUSSION...
KEY MESSAGE 1...

A secondary cold front slipping into the forecast area from the
north returns north as a warm front this morning, as a weak low
pressure center over the middle Ohio Valley drifts northeast.
While this does not intuitively appear to be the ideal setup for
radiative cooling, the light flow and dearth of moisture
associated with the weak low was allowing cooling, especially
farther east, farther from the low and where deeper, better
sheltered mountains are.

Freeze Warnings and Frost Advisories remain in effect until 8
AM this morning for frost and freeze conditions in the northern
mountain valleys as a result, with a few locations already in
the 30-32 degree F range. With marginally low temperatures for
frost and freeze conditions in the first place, temperatures
should climb high enough by the 8 AM expiration time to
essentially end the threats.

By contrast, the low was keeping temperatures high in its
proximity in east central Ohio, up in the mid 40s to even around
50. The low fills as it lifts up into the upper Ohio Valley
today, and strengthening southwest flow will make for a warmer
afternoon amid abundant sunshine today, ahead of the next system
approaching from the west, next Key Message.

KEY MESSAGE 2...

A cold front crosses the area Wednesday into Wednesday evening,
as its parent low pressure center tracks east across
southeastern Ontario, Canada. This will bring two rounds of
showers to the area.

What is left of the pre-frontal convection that develops later
today over the Midwest, arrives from the west first thing
Wednesday morning, and then treks eastward through the area
during the morning and early afternoon hours. While this is
unfavorable timing for thunderstorms, the trick of the tale is
that this line gets out ahead of the supporting mid/upper-level
short wave trough and surface cold front.

If it does so quickly enough, there may be enough recovery for
destabilization, allowing a second line of pre-frontal
convection to fire ahead of but closer to the cold front, and
then possibly become strong. The current forecast scenario puts
the best environment for stronger storms in middle Ohio Valley
during the early afternoon hours Wednesday, then progressing
eastward across the area during the remainder of the afternoon,
before exiting the mountains early Wednesday evening.

The new SPC Day 2 Outlook slightly trims the western edge of
the Marginal Risk for Severe Thunderstorms in the middle Ohio
Valley, to closer to the Ohio River, crossing it at the bend
near Huntington, the area encompassing mainly eastern portions
of the middle and upper Ohio Valley, as well as much of the
central Appalachians. Steep low-level lapse rates in the
afternoon beneath mid-level lapse rates of around 7 C/km should
support a threat for isolated severe wind gusts as depicted as
the primary threat by SPC. However, deep layer CAPE and some
veering of low level flow with height could also support hail
and low-level rotation, respectively.

The thunderstorm threat will become limited to the mountains
and quickly diminish Wednesday evening, with the showers ending
from west to east shortly thereafter Wednesday night, as the
cold front pushes on through.

While a thunderstorm can produce a locally heavy downpour,
overall rainfall amounts will only be hydrologically and
agriculturally beneficial, if that.

The short wave closes off into a mid/upper-level low over the
interior northeast Wednesday night, and lingers close by enough
for low-top convection in the northern mountains Thursday
afternoon, given daytime heating of elevated surfaces beneath
the cooler air aloft, all beneath a stout mid-level inversion
on the southwest side of the mid/upper-level low. However, that
inversion should keep convection shallow enough to preclude ice
and charge separation in cloud.

KEY MESSAGE 3...

High pressure regains control for the end of the work week with
a return to cooler weather overnight Wednesday night through
Thursday night, including a noticeably cooler afternoon on
Thursday. While wrap-around low level flow will provide enough
cloud and even enough of a wind to preclude northern mountain
valley frost formation early Thursday morning, high pressure
should allow sufficiently clear and calm conditions to develop
in time for northern mountain valley frost formation early
Friday morning. A stout warming trend will then commence on
Friday, next Key Message.

KEY MESSAGE 4...

Flat mid-level short wave troughs flatten the ridge that
initially builds in behind the mid/upper-level low that pushes
the Wednesday cold front through, Friday through Saturday. This,
along with low to mid-level warm advection ahead of a warm
front, could bring showers to the area overnight Friday night
into Saturday night, even afternoon thunderstorms on Saturday.

After that, the mid/upper-level pattern will be characterized
by a larger, more amplified ridge building in over the eastern
third of the U.S. early next week, pushing the warm front well
north of the area. As such, showers and thunderstorms become
increasingly more diurnal in nature Sunday through next Monday,
and temperatures climb to increasingly unseasonably high levels.

The heat peaks next Monday or Tuesday, ahead of the next system
approaching from the west. While there is uncertainty as to the
timing and evolution of the next system crossing the U.S., the
duration of the upcoming heat should be limited by the
progressive nature of the mid/upper-level pattern.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
Light and variable to light southeast surface flow early this
morning, except light east to northeast at PKB, will become
light southwest throughout the area late this morning, as a weak
low pressure center over the middle Ohio Valley drifts
northeast. Surface flow will become light and variable around
sunset, and then light south later tonight, increasing and
becoming gusty from the south to southwest toward dawn
Wednesday.

With the low pressure center aloft already farther north, flow
aloft will be light west to southwest early this morning, and
then light southwest later today, before increasing to moderate
southwest late tonight as a stronger system approaches from the
west.

Any fog in the deeper mountain valleys /EKN/ early this morning
should be all gone by 13Z. Increasing low level flow tonight
should preclude late night fog formation. Otherwise, once any
fog this morning is gone, VFR conditions will prevail this
period.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...

FORECAST CONFIDENCE: High.

ALTERNATE SCENARIOS: Gusty showers may be entering the middle
Ohio Valley from the west as 12Z Wednesday approaches.

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.

DATE                         TUE 05/12/26
UTC 1HRLY       07   08   09   10   11   12   13   14   15   16   17   18
EDT 1HRLY       03   04   05   06   07   08   09   10   11   12   13   14
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  M    M    L    L    L    M    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 06Z WEDNESDAY...
IFR possible in showers and thunderstorms on Wednesday.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Frost Advisory until 8 AM EDT this morning for WVZ520-522-524-
     525.
     Freeze Warning until 8 AM EDT this morning for WVZ523-526.
OH...None.
KY...None.
VA...None.

&&

$$

DISCUSSION...TRM
AVIATION...TRM