026
FXUS61 KRLX 100331
AFDRLX

AREA FORECAST DISCUSSION
National Weather Service Charleston WV
1131 PM EDT Thu May 9 2024

.SYNOPSIS...
A cold front crosses tonight ushering in cooler weather for
Friday and the weekend. The chance for rain continues at times
courtesy of crossing upper level disturbances.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 1107 PM Thursday...

Scattered showers and isolated thunderstorms continue to slide
southeast across the CWA, currently running from Elkins west-
southwest towards northeast Kentucky, as a cold front quickly
crosses. While the severe threat has ended, locally heavy rain
and gusty winds of 30 to 40 mph remain possible as this line
dissipates/exits over the next hour or two. This gives way to an
overnight with near seasonable temperatures, along with a return
of isolated showers later tonight.

As of 750 PM Thursday...

Scattered strong thunderstorms have developed across portions of
the forecast area this evening in advance of and along a cold
front, with isolated severe storms possible over the next few
hours. The main threats continue to be damaging wind gusts,
hail, and localized flash flooding, with the northeast portion
of the CWA having the greatest chance for impacts. Some weak
rotation has been noted with the cells this evening, so an
isolated, brief spin-up cannot entirely be ruled out. Activity
will continue to quickly shift southeastward over the next few
hours, with the severe threat quickly diminishing/exiting from
~ 10 PM to midnight. Have updated PoPs, temperatures, and cloud
cover throughout the night to represent the latest trends. The
rest of the forecast remains on track.

As of 220 PM Thursday...

Showers and thunderstorms are likely to fire up this afternoon,
as west to southwest low level flow increases ahead of an
approaching low pressure center and cold front. This will begin
with isolated to scattered activity this afternoon, followed by
a segmented line of convection drifting southeastward this
evening into tonight.

Clouds were limiting heating across much of the middle Ohio
Valley, versus areas nearer and in the mountains. With the
opposite pattern in terms of bulk shear, near 60 kts west but
down around 40 kts east integrated 0-6 km, overall severe
potential is marginal. Also, modest low level storm relative
helicity peaking in the 150-200 m2/s2 range will also support
some rotation in more organized cells, like within any line
segments later on.

Pockets of one hour flash flood guidance values of an inch or
less, particularly over the middle Ohio Valley, make such areas
vulnerable to excessive runoff from any heavier thunderstorm,
but vegetation nearing full growth has proven to be a mitigating
factor this week.

Cooler air and low clouds roll in behind the cold front tonight,
and Friday will be a noticeably different day with the low
overcast in place. Showers are possible in the afternoon as a
mid-upper level short wave trough crosses, but instability, if
any, will be limited.

After one last warm afternoon for a few days, central guidance
reflects cooling from northwest to southeast behind the cold
front tonight, and a noticeably cooler day on Friday with lower
60s most of the afternoon across the lowlands, actually below
normal for this time of year.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
As of 225 PM Thursday...

Precipitation ends from west to east Friday night as transient
ridging builds into the region ahead of a northern stream
disturbance approaching during the day Saturday.

With relatively cool air left in the wake of the Friday system along
with relatively early arrival of associated cloudiness, won`t
realize very much surface heating. Still, should be able to generate
some conditional instability, perhaps 500J/kg in the presence of
rather stout deep layer shear of 40 to 50KTs by Saturday afternoon.
With rather cool air aloft, graupel showers are likely, with some
stronger cores also possible yield strong to perhaps marginally
severe wind gusts.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 225 PM Thursday...

Ridging building into the region yields mainly dry conditions from
late Sunday afternoon through Monday. Deep southwesterly flow
associated with the next southern stream system will begin to advect
moisture back into the region Monday afternoon into Monday evening.
Upper level forcing arriving late Monday afternoon into early Tuesday
morning will yield an uptick in precipitation coverage. Given the
low amplitude of this feature and varied model timing, confidence is
not especially high.

Transient ridging builds back into the region briefly Wednesday
before another system arrives Thursday.

Severe risk through this period appears low given a relatively weak
flow regime.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
As of 840 PM Thursday...

Scattered showers and thunderstorms are moving southeast across
the region in advance of and along a cold front. Mainly VFR
conditions persist ahead of the front, outside of brief MVFR in
ISO showers/storms. MVFR/IFR is likely with showers and
thunderstorms along the front itself, along with variable and
gusty winds. The best chance for heavier showers/storms going
forward will be at CKB/CRW/EKN. Showers/storms will diminish in
coverage by late evening, with ISO/SCT showers and perhaps a
rumble of thunder going forward for the remainder of the
overnight. Brief MVFR VSBY is possible within showers. Additionally,
CIGs will lower into MVFR/IFR areawide by late tonight.

ISO/SCT showers persist on Friday, particularly in/near the
higher terrain, with the chance for a storm or two later in the
day. Brief MVFR VSBY remains possible within showers. MVFR/IFR
CIGs Friday morning will transition to MVFR/VFR throughout the
afternoon, with MVFR persisting longest in/near the mountains.

WSW flow this evening ahead of the front veers to NW throughout
the night, then persists as such through the end of the TAF
period. Gusty winds of 15-25 kts are possible this evening ahead
of the front, with higher gusts likely with any strong thunderstorms.
Wind gusts of 15-20+ kts are possible during the day on Friday.

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

FORECAST CONFIDENCE: Medium.

ALTERNATE SCENARIOS: Timing of ceiling and visibility restrictions
may vary from forecast. Winds will fluctuate.


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                                             FRI 05/10/24
UTC 1HRLY       03   04   05   06   07   08   09   10   11   12   13   14
EDT 1HRLY       23   00   01   02   03   04   05   06   07   08   09   10
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    M    M
HTS CONSISTENCY  H    H    M    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  H    H    H    L    H    H    M    M    H    H    H    H
EKN CONSISTENCY  M    H    H    H    L    H    M    M    M    L    H    H
PKB CONSISTENCY  H    M    H    H    H    H    L    H    L    M    H    H
CKB CONSISTENCY  M    M    H    H    H    H    H    H    H    H    H    H

AFTER 00Z SATURDAY...
IFR conditions possible Friday night into Saturday morning w/
valley fog.

&&

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

&&

$$

SYNOPSIS...TRM/JP/GW
NEAR TERM...TRM/GW
SHORT TERM...JP
LONG TERM...JP
AVIATION...GW