Area Forecast Discussion
Issued by NWS Charleston, WV

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000
FXUS61 KRLX 201845
AFDRLX

AREA FORECAST DISCUSSION
National Weather Service Charleston WV
245 PM EDT Wed Mar 20 2019

.SYNOPSIS...
Upper low/weak cold front Thursday. Another upper level trough
crosses Friday with upslope snow showers and maybe a few snow
squalls across the Lowlands. High pressure for the weekend.

&&

.NEAR TERM /THROUGH THURSDAY/...
As of 205 PM Wednesday...

Models are now in consensus keeping pretty much all of the
influences of the coastal low pressure system just to the east
of the CWA. Meanwhile, to the west, upper troughs merge over the
lower Ohio Valley lagging behind aa surface low. Frontogenetic
forcing will peak as it enters southern Ohio and weakens a bit
as it passes into the West Virginia lowlands hours later, but
the upper low keeps the threat of precipitation going across the
bulk of the western CWA. The majority of the precipitation is
snow, but the Randolph/Pocahontas area has a chance of
snow/sleet/rain mix near the onset, when wet bulbing raises the
temperature thresholds for ice. No snow or ice accumulation
expected for this issuance. Temperatures should stay on the mild
side tonight in southerly low level flow with clouds thickening,
but rebounding slowly Thursday in clouds and rain.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
As of 230 PM Wednesday...

Upper trough and reinforcing cold front will cross the region on
Friday. CAA on strong NW flow will keep temperatures well below
normal, although MOS guidance is yet to catch on, the raw model
guidance keeps highs only in the low 40s across the south and
below freezing in the mountains. Upper trough digs overhead by
midday Friday and with moisture fetch coming from the Great
Lakes, combined with steep low-level lapse rates and CAPE of
about 100 J/kg...some snow squall activity will be possible,
even across the Lowlands. Boundary layer temps will be
questionable and think with the cold temps aloft, even if temps
climb to near 40, precip is likely to fall as snow. Warm surface
temperatures will likely prevent accumulations in the Lowlands,
however in the mountains temperatures should stay below
freezing. Forecast soundings at Snowshoe show limited moisture
Friday morning, but by the afternoon the low levels saturate,
and with CAA on NW flow it appears a decent shot of upslope snow
will occur across the mountains. 1 to 3 inches is expected,
with locally higher amounts possible, but not expecting too much
more than that as high pressure builds in by Saturday morning
and scours out the remaining moisture.

High pressure will move overhead late Saturday with skies
clearing and moderating temperatures.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 240 PM Wednesday...

High pressure remains overhead on Sunday. Fair weather persists
and the area warms up with the potential to reach into the 60`s
area wide. Models are in good agreement with the next system
arriving by Monday morning, however they diverge on when the
precipitation will exit. The GFS has it quickly exiting the
area Tuesday morning, however the Euro has been going back and
forth with the new 12Z guidance pulling it out Tuesday evening
while the 00Z guidance had it leaving not until late Wednesday.
This system should stay mostly rain, however there is a chance
that colder air pushes in on the back-end and a brief period of
light snow is possible...especially in the north and mountains.
When the system exits, high pressure should be in control
through the remainder of the week.


&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
As of 135 PM Wednesday...

High level clouds thicken with the approach of an upper level
low from the west. A line of showers will push into the Ohio
River Valley after 09Z Thursday, reaching the westernmost
terminal at HTS 11Z or later. Restrictions will be slow to come
by in light rain, as ceilings will be slow lower, with rain
falling out of VFR levels, and only into MVFR potentially late
in the period. Visibilities will be similar as well as it takes
some time for the lowest levels to saturate and restrictions to
occur.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z THURSDAY...

FORECAST CONFIDENCE: High.

ALTERNATE SCENARIOS: Timing of rain may vary slightly.

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.

UTC 1HRLY       18   19   20   21   22   23   00   01   02   03   04   05
EDT 1HRLY       14   15   16   17   18   19   20   21   22   23   00   01
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  H    H    H    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  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 18Z THURSDAY...
Brief IFR possible Thursday in rain and snow showers, lasting
through Friday in the mountains.

&&

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

&&

$$
SYNOPSIS...26/MPK
NEAR TERM...26
SHORT TERM...MPK
LONG TERM...MPK
AVIATION...26



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