Area Forecast Discussion
Issued by NWS Charleston, WV

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000
FXUS61 KRLX 092001
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
301 PM EST Sun Dec 9 2018

.SYNOPSIS...
Low pressure brings heavy snow to far Southern West Virginia and
Southwest Virginia into tonight. High pressure for the middle
of next week. Strong system towards the end of next week.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 250 PM Sunday...

Low pressure to our south will continue to produce snow across
the southern portion of the CWA this afternoon and into this
evening. As this system pushes east snow should diminish in
intensity and gradually end across the area around midnight
tonight. High pressure will build in across the region as the
low exits overnight. Went lower than guidance temperatures with
snow cover south and clearing skies over the rest of the area
tonight. Also, went lower with highs tomorrow as
well...especially over the areas with snow cover.


&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 145 PM Sunday...

Fairly quiet for the short term period with surface high pressure
passing by to the south. With clear skies and some snow on the
ground across the far south, tweaked min temps a few degrees lower
than previous forecast for Monday night/Tuesday morning.

A weak 500mb shortwave trough crosses to the north on Tuesday, which
could bring some clouds to the northern forecast area but not
expecting any precipitation. A 500mb ridge then crosses Wednesday,
kicking of a warming trend into the long term.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 145 PM Sunday...

Shortwave energy will be moving towards the region Wednesday night
with the ECMWF hinting at some light QPF impacting the western
portions of the forecast area through Thursday morning. The GFS,
however, is further north with this feature and does not support any
QPF for the forecast area during this time. While a chance of some
very light rain/snow showers could occur through Thursday morning,
no accumulation is expected.

As the leading shortwave quickly departs to the east Thursday
afternoon, attention quickly turns to a much stronger system. Rapid
cyclogenesis is expected to occur Thursday evening as a vertically
stacked low pressure system traverses across the lower Mississippi
Valley. After Thursday evening, model solutions begin to diverge
with the GFS solution tracking the surface low towards the Ohio
Valley by Friday evening and ECMWF tracking the system across the
Gulf Coast through this time. With surface temperatures expected to
hover around freezing Friday morning when precipitation
initially arrives, there is a possibility of a wintry mix of
precipitation along the east slopes of the Appalachian Ridge.
This threat would be very brief as southerly flow increases and
effectively scours out any sub-freezing air at the surface.
Therefore, am anticipating just rain by late Friday morning and
possibly heavy at times if the GFS solution verifies with
bringing better dynamics/lift into our area.

By next weekend, the models continue to diverge even further.
The farther south ECMWF solution brings the system off the
southeast coast by Saturday evening while the GFS solution
brings the system into central Pennsylvania with moisture
wrapping around the backside of the low keeping conditions
unsettled in our region for the weekend. Until better model
agreement occurs, will leave slight chance POPs in the forecast
for now.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
As of 100 PM Sunday...

Storm system tracking to our south will bring snow and IP as far
north CRW and points south.

IFR/LIFR cigs/vsbys in snow and fog at BKW and will continue
this afternoon before tapering off this evening and becoming VFR
after 05Z tonight.

Mainly VFR conditions at CRW with brief MVFR cigs with light
snow at CRW at times early this afternoon. Then VFR conditions
for CRW late this afternoon and for the rest of the forecast
period.

Rest of TAF sites will remain VFR throughout the rest of the
forecast period.


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


FORECAST CONFIDENCE: High to Medium.

ALTERNATE SCENARIOS: Timing and intensity of snow at KBKW may
vary. MVFR snow and IP at CRW may vary this afternoon.

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
EST 1HRLY       13   14   15   16   17   18   19   20   21   22   23   00
CRW CONSISTENCY  M    M    M    M    H    H    H    H    H    H    H    H
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  L    M    L    M    M    M    M    L    L    M    L    L
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 MONDAY...
IFR conditions are not expected.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Winter Weather Advisory until midnight EST tonight for WVZ026-
     517-520-524.
     Winter Storm Warning until midnight EST tonight for WVZ024-025-
     033-034-515-516-518.
OH...None.
KY...None.
VA...Winter Storm Warning until midnight EST tonight for VAZ003-004.

&&

$$
SYNOPSIS...JS/MZ/RG
NEAR TERM...JS
SHORT TERM...MZ
LONG TERM...RG
AVIATION...JS


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