247
FXUS61 KRLX 220457
AFDRLX

AREA FORECAST DISCUSSION
National Weather Service Charleston WV
1257 AM EDT Sat Jun 22 2024

.SYNOPSIS...
The heat wave continues today courtesy of a broad upper level
ridge. A cold front crosses Sunday night, bringing showers and
storms to the area, and an end to the heat wave.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1255 AM Saturday...

A ridge of high pressure will continue to provide above normal
temperatures across the area. Although the airports have not
been hitting Heat Advisory criteria, some of the warmer valleys
have been, especially in cities. Therefore, will continue the
Heat Advisory for the lowlands. Models indicating a small chance
of afternoon thunderstorms along the mountains.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
As of 255 PM Friday...

The upper level ridge associated with the current heat wave gets
shunted off to the deep south/southwestern U.S. this weekend, as
a mid-upper level short wave trough approaches. Increasing
forcing and modest 0-6 km bulk shear of 20-30kts acting on the
afternoon instability amid the hot, humid air mass, with CAPE
building to 2-3 KJ/kg in an axis ahead of the front, leads to
the potential for strong to marginally severe thunderstorms
Sunday afternoon and evening across the lowlands. The severe
threat decreases as convection crosses the mountains overnight
Sunday night, as instability decreases.

Showers and thunderstorms will have modest motion so, while PW
values up around two inches could result in locally excessive
downpours, widespread high water instances are not expected.

Central guidance evinces a very arm and humid Saturday night,
with rising temperatures on Sunday intercepted by increasing
clouds and developing convection, soon enough to preclude
extending the heat advisory into Sunday. Lows Monday morning
will be perceptibly lower across northwest portions of the
forecast area, slightly lower southeast, compared with Sunday
morning.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 255 PM Friday...

A cold front exits the forecast area Monday morning, bringing an
end to the prolonged heat wave. Its trailing positively-tilted
short wave trough, extending southwestward from a mid-upper
level low crossing northern New York and New England Monday,
crosses Monday morning and midday.

Showers will be limited to the mountains by dawn Monday, where
there may still also be a thunderstorm, depending upon the
timing of the front. This precipitation will gradually
dissipate during the day, with little if any opportunity for a
diurnal resurgence, as cooler and much drier air advects in
beneath the crossing short wave trough, with a strong post-
frontal/subsidence inversion.

High pressure builds in Monday afternoon, crosses Monday night,
and then exits Tuesday morning. This will bring about a clear,
comfortably cool night Monday night, with calm conditions
allowing valley fog to form.

The upper level ridge associated with the current heat wave
remains shunted off to the deep south/southwestern U.S. next
week, allowing west to northwest mid-upper level flow with
embedded short wave troughs/convective complexes over the area.
With low level south to southwest gradient flow behind the
exiting high feeding increasing warmth and moisture back into
the area, showers and thunderstorms become possible Tuesday
night, and then remain so until a deep enough short wave trough
pushes a cold front through the area Wednesday night or
Thursday.

Central guidance reflects temperatures and dew points lower by
several degrees compared with those during the current heat
wave, but enough to bring perceptible relief. The heat returns
Tuesday and Wednesday of next week as heights rebuild, but with
the ridging off to the southwest of the area, it will not be as
hot as this week. The heat will also be not as persistent, given
the passage of cold front later in the week.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
As of 1255 AM Saturday...

Some patchy fog can be expected early this morning, mainly in
mountain river valleys. There is also a small chance of
afternoon thunderstorms along the mountains, but chances are
too small to include in the TAFs. Outside of these 2 items,
expect VFR conditions.

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

FORECAST CONFIDENCE: Medium with fog, otherwise high.

ALTERNATE SCENARIOS: Timing and density of fog could vary.

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 06/22/24
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    M    L    M    M    L    H    H    H
HTS CONSISTENCY  H    H    H    H    H    M    L    M    H    H    H    H
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  H    H    M    L    L    M    M    L    L    H    H    H
PKB CONSISTENCY  H    H    H    H    M    L    L    M    H    H    H    H
CKB CONSISTENCY  H    H    M    M    M    L    M    M    H    H    H    H

AFTER 06Z SUNDAY...
No widespread IFR conditions are expected at this time.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Heat Advisory until 8 PM EDT this evening for WVZ005>011-
     013>020-024>032-039-040.
OH...Heat Advisory until 8 PM EDT this evening for OHZ066-067-075-
     076-083>087.
KY...Heat Advisory until 8 PM EDT this evening for KYZ101>103-105.
VA...None.

&&

$$

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