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628
FXUS61 KRLX 010638
AFDRLX

AREA FORECAST DISCUSSION
National Weather Service Charleston WV
238 AM EDT Wed May 1 2024

.SYNOPSIS...
Dense fog this morning as a cold front exits. High pressure
brings dry weather with a warming trend today into Friday.
Shower chances increase for the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
As of 200 AM Wednesday...

A cold front has moved off to our northeast and a surface trough
sits east of the Appalachian Mountains. Skies will continue to
clear and winds will calm as a result. These factors, paired
with lingering low-level moisture from recent rainfall, will
allow the perfect setup for widespread dense fog with low
visibilities this morning.

Sheltered river valleys and mountain valleys with poor drainage
winds will see the lowest visibilities, which could be below a
quarter of a mile at times. A statement has been issued across
the entire forecast area for visibilities of a quarter of a mile
or less that will likely be observed within thicker fog columns.
Caution should be used traveling this morning.

Fog will lift and clear after sunrise this morning and a dome
of high pressure over the Deep South will move up over the area.
This feature will reinforce dry weather and invoke the start of
another warming trend under southwesterly flow. Temperatures
today look to be fairly warm with highs in the low to mid 80s
across the lowlands; 60s to high 70s in the mountains.

Another round of fog looks possible again tonight into Thursday
morning, though will not be as widespread and intense with low-
level moisture drying out this afternoon. Overnight lows will be
in the 50s again as we decouple under the high pressure.

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
As of 100 PM Tuesday...

A weak cold front stalls north of the region Wednesday night
amidst high zonal flow aloft yielding little in the way of
sensible weather concerns. This high zonal pattern gives way to
a building longwave ridge Thursday yielding continuing dry and
increasingly hot conditions for Thursday and most of the day
Friday.

50th percentile guidance is rather high for daytime highs both
days. Deterministic central guidance reflects highs several
degrees lower. Even these might be a little high given the
flush state of Spring vegetation across most of the area,
especially on Friday when at least some Gulf influence moisture
should start returning to the area prior to maximum heating.
This is likely a result of the 30 day bias period looking back
before we were properly greened up. Temperature records are
most likely secure with most reflecting values higher than even
the rather aggressive 75th percentile guidance.
-- End Changed Discussion --

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 100 PM Tuesday...

Increasing southwesterly flow in response to the ridge axis shifting
shifting east Friday along with surface low pressure transiting
the Upper Great Lakes yields an increasingly moist column late
Friday afternoon into Friday night. Precipitable water values
edge up toward 1.5 inches ahead of the approach of a cold front
associated with the aforementioned Great Lakes low Friday night.
Upper level support for this feature largely stays well to the
north allowing the front to wash out Friday night into Saturday.
This will also keep deep layer shear rather weak also yielding
relatively slow storm motions. Could potentially have some very
isolated water issues with multiple slow moving storms moving
over the same location, but given the state of vegetation and
recent dry conditions, concerns are relatively low.

The weak flow pattern persists through the weekend featuring mainly
diurnally driven convection.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
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As of 108 AM Wednesday...

Widespread dense fog will allow for IFR/LIFR restrictions or
lower across the forecast area this morning as skies begin to
clear from west to east and winds decrease. Shortly after
sunrise, dense fog will start to lift and dissipate between
~12-13Z, subsequently giving way to VFR under mostly clear
skies. This will last through the day until another round of
river valley fog arrives overnight into Thursday.

Winds calm to light and variable this morning, becoming light
and SW`rly during the day.

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


FORECAST CONFIDENCE: Medium.

ALTERNATE SCENARIOS: Timing and intensity of dense fog this
morning could vary. Low stratus could form across the higher
portions of the mountains instead of dense fog.


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                              WED 05/01/24
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  L    M    M    M    H    H    H    M    H    H    H    H
HTS CONSISTENCY  L    H    H    H    H    H    H    L    L    H    H    H
BKW CONSISTENCY  H    H    M    H    H    H    L    L    H    H    H    H
EKN CONSISTENCY  M    M    M    M    M    M    M    L    H    H    H    H
PKB CONSISTENCY  M    M    H    H    H    H    M    L    H    H    H    H
CKB CONSISTENCY  L    L    M    H    H    H    M    M    H    H    H    H

AFTER 06Z THURSDAY...
IFR conditions possible due to fog Thursday morning.
-- End Changed Discussion --

&&

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

&&

$$

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