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508
FXUS61 KRLX 020813
AFDRLX

AREA FORECAST DISCUSSION
National Weather Service Charleston WV
413 AM EDT Thu May 2 2024

.SYNOPSIS...
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High pressure brings dry weather with a warming trend today
into Friday. A cold front brings showers and storms as it
washes out over the area this weekend. Active next week.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 130 AM Thursday...

An upper level ridge remains over the area today while a frontal
boundary - initially located near the northwest fringe of the CWA -
is lifted further north as a low moves out of the Central Plains
and approaches the Great Lakes later today. Dry low-level air
should allow dry conditions to persist across the area today,
though some mid to high level clouds may continue to drift
overhead.

Ridging begins to slide east tonight as a cold front slowly
approaches from the west. While quiet weather should linger
through the night, a gradual increase in cloud cover is expected
to occur ahead of the front.

After a mild morning, daytime highs are expected to climb into
the upper 80s in the lowlands and 70s to 80s along the
mountains. Tonight will be mild again with lows likely to be in
the 50s to 60s.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
As of 340 AM Thursday...

Sustained periods of dry periods are elusive in both the short
and long term periods.

The short term does start dry, with mid-upper level ridging
exiting ahead of a southern stream short wave trough and surface
cold front approaching from the west. There are some model
differences in whether these features roll into the area Friday
midday through evening, or Friday afternoon and night. The
latter would allow more dry time and daytime heating Friday,
while the former brings clouds, showers and thunderstorms in
earlier. The forecast sticks with the later timing.

Even so, some increase in cloud during the morning and midday,
and modest dew points of around 60 or even lower, will likely
contribute to modest instability Friday afternoon, with CAPE
less than a KJ/kg. Given modest low to mid level flow/shear,
thunderstorms are not expected to be especially strong, but they
can produce heavy downpours and gusty winds in the middle Ohio
Valley by late in the day.

As the system lifts northeastward through the area, the surface
cold front washes out, stranding the area in southerly flow of
very warm and increasingly humid air amid additional short wave
ripples in the mid-upper level southwest flow. Showers and
thunderstorms are likely Friday night through Saturday, and even
into Sunday. The nearly saturated atmosphere will not be that
unstable, but PW values could climb to 1.5 inches or higher, so
heavy downpours are a good possibility. However, the growing
vegetation and recent dry weather should minimize the potential
for high water.

By later in the day Sunday, the short wave trough exits, giving
way to ridging, lessening shower and thunderstorm coverage
Sunday afternoon, compared with Saturday afternoon, at least
across the middle Ohio Valley.

Unseasonably warm conditions continue Friday as mid-upper level
ridging slowly works east of the area. While central guidance
highs Friday are 10 to nearly 15 degrees above normal for early
May, they are still comfortably below record highs for the date.
After a rain-cooled Saturday, perhaps not too unlike Tuesday,
highs moderate a bit on Sunday given decreasing shower and
thunderstorm coverage. Nights remain unseasonably mild for this
time of year.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
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As of 410 AM Thursday...

The weather pattern remains active in the long term, but with
increasing model uncertainty, particularly with timing.

While short wave ridging amd loss of heating will result at
least a decrease in shower and thunderstorm coverage Sunday
night, another southern stream short wave trough undercutting a
larger ridge migrating from the midwest to the Great Lakes
arrives first thing Monday morning. This, with what is left of
the cold front that washes out this weekend gaining new life as
a warm front, showers become likely again Monday afternoon,
along with the chance for thunderstorms. Its exit, amd loss of
heating, will result at least a decrease in shower and
thunderstorm coverage again Monday night,

A large mid-upper level low migrates from the northern plains
to the Great Lakes next week while becoming elongated west-
southwest to east-northeast. Intense surface low pressure over
the northern plains Tuesday fills in favor of another center
forming over the Great Lakes Wednesday. All this serves to drag
the cold front associated with the system closer to the area,
keeping the possibility for showers and thunderstorms going.

With the pattern a bit more amplified by this time, there may be
increased instability ahead of the cold front, giving rise to
stronger afternoon and evening thunderstorms, and more
opportunity for heavy downpours. In the warm and humid
environment heading toward mid May, coverage will be greatest
and storms strongest during the afternoon and evening, with the
overnight and morning minimum.

Southwest mid-upper level flow associated with the elongated low
gradually veers to west-southwest through Thursday, gradually
nudging a weakening initial cold front into the area, keeping
the unsettled weather going.

Central guidances reflects a gradual moderation in temperatures
next week, getting further above normal and more typical of mid
summer than early May.
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&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
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As of 130 AM Thursday...

VFR conditions are currently present across the area, while high
level clouds move overhead. A few areas of fog could attempt to form
towards daybreak, though confidence in development is low. Sub-
VFR CIGs/VIS could be possible if fog does form early this
morning, then flight conditions would improve back to VFR
shortly after sunrise and remain VFR for the rest of the TAF
period.

Calm to light winds are expected to linger into the morning, then
winds remain light and variable for the rest of the day.

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

FORECAST CONFIDENCE: Low for fog, otherwise high.

ALTERNATE SCENARIOS: Fog may not form this morning.

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                              THU 05/02/24
UTC 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
EDT 1HRLY       02   03   04   05   06   07   08   09   10   11   12   13
CRW CONSISTENCY  H    H    H    H    L    L    H    H    H    H    H    H
HTS CONSISTENCY  H    H    H    L    L    H    H    H    H    H    H    H
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  H    H    H    H    H    H    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 FRIDAY...
IFR possible in rain and storms Friday night through Saturday,
and in stratus and fog Sunday morning.
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&&

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

&&

$$

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