Area Forecast Discussion
Issued by NWS Charleston, WV

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KRLX 141800
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
100 PM EST Tue Nov 14 2017

.SYNOPSIS...
Cold front crosses late Wednesday. High pressure crosses
Thursday night. Strong cold front for Saturday.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
As of 100 PM Tuesday...

Low stratus has been tough to scatter east of the Ohio River
thus far as the low level flow gradually veers around to the
east amid negligible WAA thus far. As the flow turns more
southeasterly and WAA increases this evening, much of the
lingering stratus should erode. Of course this will lead to the
eastern slopes locking in low clouds overnight. Lows were
derived from a blend of a consensus approach.

Wednesday morning should start with sunshine, but quickly become
filtered by an advancing cirrus canopy ahead of an approaching
cold front. Despite this, temps in the southeast flow downslope
areas should reach upper 50s. Timing of the front looks to hold
off until Wednesday evening...though prefrontal band of showers
will work in from west to east late in the afternoon.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 300 AM Tuesday...

Weak return flow out ahead of an approaching cold front will
send temperatures back into the upper 50s for a large portion of
the area on Wednesday. Models continue to be in fairly good
agreement with the arrival of the front Wednesday evening into
the Ohio Valley. Still lacking any significant moisture and with
weak forcing in zonal flow aloft, this front will push through
the area fairly quickly with just a light rainfall. By Thursday
morning we may see a brief transition to a few snow showers in
the mountains as some colder air briefly pushes in, but do not
think we will see much in the way of accumulation before the
upper trough pulls out by early Thursday afternoon. Brief
surface high and upper ridge moves in behind the front and this
should make for a good radiational cooling night, with lows
likely dipping below freezing by early Friday morning.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 325 AM Tuesday...

As we head into the weekend, model solutions diverge with the
timing of a potent short wave and associated surface cold front.

GFS strengthens the low tracking out of the Rockies and NE over
the Great Lakes much deeper than the Euro. The overall pattern
is much more amplified as well with the GFS indicating closed
low and deep trough across the Eastern Conus that pushes in much
colder air behind the front, while the Euro brings in high
pressure and WAA returning by Monday. GEFS spaghetti plots
indicate there is still a ton of uncertainty in how the pattern
will materialize this weekend as well.

The operational solutions both at least have the potent cold
front that could bring a quick dumping of heavy rain and some
gusty winds, but timing is off and what happens after that
front goes through is anyones guess at this time. Hopefully the
models will sort this out better over the next few runs when
soundings can better sample the associated short wave when it
enters the West Coast on Thursday.

For now, overall forecast for this weekend is a blend of
ensemble and operational guidance. I did add a bit higher PoPs
in the favorable upslope areas in NW flow for Sunday. Even
though the Euro is not nearly as robust with the CAA behind the
front, it does indicate a 12 hour period on Sunday where some
upslope snow will be possible, and the GFS of course indicating
a higher impact upslope snow event.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
As of 100 PM Tuesday...

Lingering low stratus and stratocu will keep general MVFR for
HTS/CKB/EKN/BKW thru 20Z, after which bases should rise into low
end VFR before scattering out this evening.

Low level flow turns more southeasterly and increases 10 to 15
kts. This should prevent dense fog formation at the terminals,
save for some MVFR vsby at EKN. Low stratus on the eastern
slopes may sneak into BKW during the predawn, but confidence not
high enough to include in TAF at this distance.

VFR conditions dominate Wednesday 12 to 18Z as cirrus advances
into the area.

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

FORECAST CONFIDENCE: High.

ALTERNATE SCENARIOS: Timing of improvement this afternoon may
vary an hour or so. MVFR cigs may develop into BKW overnight.

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  H    H    H    H    M    M    H    H    H    H    H    M
HTS CONSISTENCY  H    H    M    M    M    H    H    H    H    H    H    M
BKW CONSISTENCY  M    M    M    M    H    H    H    H    H    H    H    M
EKN CONSISTENCY  M    M    H    H    H    H    H    H    H    H    H    M
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
CKB CONSISTENCY  H    M    H    H    H    H    H    H    H    H    H    M

AFTER 18Z WEDNESDAY...
IFR possible behind a cold front overnight Wednesday night into
Thursday morning, mainly in stratus.

&&

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

&&

$$
SYNOPSIS...30/AB
NEAR TERM...30
SHORT TERM...MPK
LONG TERM...MPK
AVIATION...30



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.