Area Forecast Discussion
Issued by NWS Charleston, WV-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KRLX 220600
Area Forecast Discussion
National Weather Service Charleston WV
146 AM EDT SUN MAY 22 2016
-- Changed Discussion --Mid and upper level low drops southeast and lingers in mid Atlantic
states into Monday night. High pressure over Ohio/Tennessee Valleys
Monday into Tuesday.
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.NEAR TERM /THROUGH TODAY/...
1030 PM UPDATE...
Made some tweaks to the overnight sky grids given current trends.
Thinking some clearing will work into SE OH/NE KY/SW WV overnight.
Tough to figure fog potential in areas that clear...but given a 20
kt wind just off the deck...think fog would be confined to more
745 PM UPDATE...
Cold front pushing east thru the mountains as of 00z. This should
take the bulk of the shra with it. However cannot rule out a stray
shra or two this evening until the final s/w trof axis crosses
Still thinking low stratus will be the rule overnight...generally
from CRW/CKB on east. Some clearing may try to work into SE OH/NE
KY/W WV late with more of a fog threat in the valleys. The low
level flow may prevent dense fog formation on the hills.
PREVIOUS DISCUSSION BELOW...
Numerous showers and isolated thunderstorms have popped up this
afternoon in response to an upper level short wave trough digging
inn from the northwest, and low level cyclonic convergent flow
with the remnants of a surface low pressure system over the area.
Beneath the upper level trough, a surface front was pushing
southward into the middle ohio valley, with gusty winds and a more
solid stratus deck in its wake.
The surface low and cold front will collapse southeastward through
the area through this evening, as the upper level short wave
trough continues slowly digging in. It will close off into an
upper level low Sunday that will then drift southward through the
The showers were producing heavy downpours but were also on the
move, and will dissipate tonight with the loss of heating; they
are most likely to persist in the mountains. Otherwise the
stratus will fill back in, especially as the front passes.
Sunday will bring mixing, which will break up much of the fog and
stratus in the morning, but result in a repeat of pop up showers
and thunderstorms, especially over the mountains under the upper
level low. With lower freezing and -20c levels, instead small
hail for Sunday afternoon thunderstorms, with gusty winds also
possible. We should also be able to mix 20 kt gusts to the surface
outside showers and storms.
No major changes to temperatures in light of the latest guidance.
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
Influence of upper level low will continue through the first 24 to
36 hours of the short term period. Showers can be expected across
the Eastern Mountains in West Virginia and with cold temps aloft
and weak instability...an isolated thunderstorm or two will also
be possible monday afternoon in the Northern Mountains. Upper
level low finally drifts northeast on Tuesday and upper ridge
moves overhead making for a great weather day.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
The dry weather we get on Tuesday will be short-lived as upper
ridge breaks down and is replaced with zonal flow aloft. This
pattern is looking very summer-like as we end up on the edge of
the Bermuda High. Southwesterly flow will push warm and moist air
from the Gulf of Mexico into the region...and dew points may
approach 70F by the end of the work week. There will be a threat
for showers and thunderstorms each day from mid week to the
weekend in the moist airmass as we maximize daytime heating in the
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --Kept confidence at low. Tough to figure ceilings and fog through
12z this morning.
Drier air and clearing moving into mid Ohio Valley around Pkb to Hts
near 06z. Confidence low on how far east the partial clearing
progresses 06z to 12z..as flow begins to veer toward north.
Will try to form some diurnal fog in southeast Ohio and the Pkb to
Hts vcnty for the 06z to 12z time frame with local ifr.
Further east...the stratus was trying to lift ckb to crw at 06z.
Will hold onto more clouds and less fog development...but confidence
A mid level circulation drops southeast out of Pennsylvania toward
northern Virginia after 21z today. In respond...shower coverage
should increase between 15z to 18z vcnty ckb to ekn...then reach crw
to bkw vcnty after 20z.
Drier dew points and mixing should lift ceilings today. So after
15z...have mostly 4 to 6 thsd ft bkn ceilings...except over
mountains with 2 to 3 thsd ft. An isolated thunderstorm may develop
over West Virginia after 18z thru 00z Monday.
Scattered showers linger ekn-bkw after 00z to 06z as flow veers more
toward the northeast.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z MONDAY...
FORECAST CONFIDENCE: Low.
ALTERNATE SCENARIOS: Low level flow above boundary layer may prevent
thicker fog in Pkb to Hts for the predawn hours.
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 SUN 05/22/16
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 M M M M M M M H H M H H
HTS CONSISTENCY H H M L L L M H H H H H
BKW CONSISTENCY L L L L L L L L M M M H
EKN CONSISTENCY L L L L L L L L L L M M
PKB CONSISTENCY M M L L L L M H H H H H
CKB CONSISTENCY L M M M M M M M M M M H
AFTER 06Z MONDAY...
IFR in fog possible late Monday night into Tuesday morning.
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