416
FXUS61 KRLX 010951
AFDRLX

AREA FORECAST DISCUSSION
National Weather Service Charleston WV
551 AM EDT Sat Jun 1 2024

.SYNOPSIS...
Exiting high pressure brings one more dry day, before
disturbances bring showers and storms Sunday into the new work
week, with a break on Monday, and above normal temperatures.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 550 AM Saturday...

Forecast on track, with less valley fog compared with Friday
morning.

As of 230 AM Saturday...

Patchy mountain valley frost at deeper high-elevation mountain
valley cold spots still appears plausible early this morning.
Elsewhere, river valley fog should not become quite as
pronounced as early Friday morning, owing to the high cloud, a
light puff just above the surface, and another day of drying.

Exiting high pressure will bring one more dry day today,
although the process of sunshine being filtered and increasingly
obscured by high cloud will be the harbinger of the next low
pressure system arriving from the west. Clouds will lower and
thicken tonight, with showers becoming likely at least across
the middle Ohio Valley overnight.

The NAM suite and HIRES FV3 core evince a band of precipitation
scooting all the way into the central Appalachians by dawn
Sunday, with a break behind it in the HTS tristate and Tug Fork
areas.

Elevated narrow CAPE may allow for at least in cloud lightning
with a few rumbles of thunder, but of slightly greater concern
are PW values of around 1.5 inches overspreading at least the
middle Ohio Valley by dawn Sunday, on a 35-40 kt h85 theta-e
feed from the southwest, with cloud tops possibly dropping below
the ice in cloud level fostering the efficient warm rain
process.

Central guidance evinces a warmer afternoon today, and then
less of a ridge-valley split amid an increasingly cloudy, and,
eventually, rainy night tonight.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 230 AM Saturday...

This period starts with a weak surface low passing just toward
our north. This feature will drag a weak frontal boundary
through which will be enough to support shower and thunderstorm
activity, however looking at soundings with the lack of shear
and instability, we are likely looking at sub-severe storms.
PWATs have increased along with long skinny CAPE coming into
the equation which will support more rainfall and possibly heavy
downpours and thankfully DCAPE is very low which will decrease
the chances for downbursts.

The frontal boundary will pass by nightfall and then from there
on weak high pressure both at the surface and loft will build
in from the west for a short period on Monday. Unfortunately the
weak high pressure will allow for some diurnal activity as far
as shower and storms are concern. This will likely be confined
to the mountains due to the elevated heat effect although we
cannot rule out a possible storm elsewhere.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 230 AM Saturday...

For Tuesday, this day did a complete 180 degree switch from
yesterday with going from being unsettled to fairly quiet
weather with surface high pressure staying in the vicinity along
with stronger ridging aloft. This equates to quieter weather
for most of the day. However some activity may occur during the
afternoon and evening hours and mostly confined to the
mountains.

Models are in better agreement on timing with the next system
to affect the area. This feature will bring a cold front
associated with a parent low traversing across the Great Lakes.
This potent low will drop the frontal boundary down and slowly
pass it through as the potent low becomes stronger and slides
south not progressing toward the east, therefore slowly inching
toward the area and not away.

Activity ahead of the aforementioned cold front will take place
on Wednesday and then frontal passage will take place on
Thursday if everything cooperates. Models then have the low
dipping down and affecting the area with wrap around flow which
will keep unsettled weather in the area for the weekend,
according to models, which has another frontal boundary wrapping
around through the area on Saturday, but at that point models
diverge. Decided to go with blended model guidance toward the
end of this period. This equated to very high POPs for Wednesday
and Thursday with thunderstorm activity possible around the
clock. Friday will not be a washout, but will have chances of
showers and chances of diurnal thunderstorms.

Southerly flow will keep warm moist air pumping into the area
from Tuesday through Thursday promoting temperatures above
seasonable by about 10 degrees.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
As of 550 AM Saturday...

Any river valley fog should be gone by the start of the TAF
period, 12Z, and high pressure maintains mainly VFR conditions
through the period, as it exits to the east. High clouds will
gradually lower and thicken this afternoon and tonight,
harbinger of the next low pressure system approaching from the
west.

Showers are likely to move into at least the middle Ohio Valley
overnight tonight, if not all the way to the central
Appalachians by 12Z Sunday. At least in-cloud lightning is also
possible. The showers can lower visibility and even ceilings
down to MVFR near or just after the end of the TAF period, 12Z
Sunday.

Calm to light and variable surface flow early this morning will
become light south to southeast today. Light southwest flow
aloft early this morning will become light south today, and then
light to moderate south to southwest tonight.

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

FORECAST CONFIDENCE: High.

ALTERNATE SCENARIOS: Showers can lower visibility and even
ceilings don to MVFR by the end of the TAF period, 12Z Sunday,
when thunder is also possible in the middle Ohio Valley.

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               SAT 06/01/24
UTC 1HRLY       09   10   11   12   13   14   15   16   17   18   19   20
EDT 1HRLY       05   06   07   08   09   10   11   12   13   14   15   16
CRW CONSISTENCY  M    M    M    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  H    M    M    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  L    L    L    M    H    H    H    H    H    H    H    H
PKB CONSISTENCY  H    M    M    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  H    M    M    H    H    H    H    H    H    H    H    H

AFTER 12Z SUNDAY...
Brief IFR conditions possible in showers and thunderstorms on
Sunday, then again at times late Tuesday into Thursday. IFR also
possible in post-rain stratus, and perhaps fog, late Sunday night
and early Monday morning.

&&

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

&&

$$

SYNOPSIS...TRM/JZ
NEAR TERM...TRM
SHORT TERM...JZ
LONG TERM...JZ
AVIATION...TRM