Area Forecast Discussion
Issued by NWS Charleston, WV
FXUS61 KRLX 061459
Area Forecast Discussion
National Weather Service Charleston WV
959 AM EST Tue Dec 6 2016
Low pressure crosses today and tonight, bringing freezing rain to
very high terrain, and rain elsewhere. High pressure Wednesday. A
cold front crosses early Thursday. Much colder into the weekend.
.NEAR TERM /THROUGH TONIGHT/...
As of 1000 AM Tuesday...
Forecasts remains on track. No changes necessary.
As of 630 AM Tuesday...
Forecast on track.
As of 420 AM Tuesday...
Miller B type low pressure system crosses today, its primary
center filling as it moves up the Ohio River Valley, giving way to
a second center that tracks across the Carolinas to the east
coast. Widespread rain moving into the area as a result early
this morning will make for a wet day today. Models continue to
paint a half inch to an inch of rain on average, with the highest
amounts in the mountains, and west of the Ohio River, with the
typical southeast downslope rain shadow resulting in the lower
amounts over the WV lowlands.
Cold air beneath frontal inversion will result in freezing rain
across the very high terrain given the cold air damming wedge
developing early this morning. Outside the radiation inversion
northeast of the area, the air upstream (to the northeast) is not
quite cold enough to support ice. However, upslope flow will
result in sufficient cooling high along the eastern slopes for
freezing rain across the very highest terrain.
With the wedge developing this morning and then only gradually
eroding later this afternoon, the 7 PM end time of the freezing
rain advisory looks good, although the lower terrain within the
advisory area may not experience much icing at all.
The cold front moves through later tonight as the system pushes
east, with the coastal low pressure center having taken over. This
will finally take out the cold air damming wedge. However, colder
air moving back in behind the system, coupled with the loss of all
but low level moisture, may result in freezing rain or freezing
drizzle, again across the very high terrain, early Wednesday
A blend of the NAM, MET and a short term consensus appeared to
have the best handle on temperatures, a bit higher in the
advisory area than the previous forecast.
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
As of 420 AM Tuesday...
Overall, brief break in the precipitation expected for Wednesday as
high pressure briefly takes hold. Could still be some areas of -DZ
early Wednesday morning behind departing low, but overall, expecting
a drier, day, with some partial clearing in cloud cover.
Precipitation will return to the area however by Thursday as a
combination of an upper level trough, sags south into the area,
allowing for colder air to infiltrate into the region, and favorable
northwesterly flow to set up off the Great Lakes, allowing for some
-shsn, and from a shortwave that will track northeast through the
region early in the day Thursday. Expecting light snowfall
accumulations, mainly across mountains in favored upslope regions,
with little to no accumulations across the lowlands. In addition to
the colder air/-shsn, expect breezy conditions on Thursday due to
CAA. -shsn will continue on Friday, along with blustery conditions,
as northwesterly flow remains in control.
.LONG TERM /SATURDAY THROUGH MONDAY/...
As of 420 PM Tuesday...
Milder air to take hold over the weekend as weak upper ridging
builds in response to approaching sw trough/low pressure system,
which will spread precipitation, mostly in the form of rain, except
for across the higher terrain, back into the region by the end of
the week, with a transition over to snow showers late Sunday night
into Monday as the system departs and colder air infiltrates into
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
As of 100 AM Monday...
A low pressure system crossing the area this period will bring
MVFR to IFR conditions in rain today. Freezing rain today will
occur along the higher eastern slopes of the mountians, and icing
is possible aloft in that area below an inversion, which will be
3-4 kft MSL.
As the rain exits this evening, visibilities will improve, but
low MVFR to IFR stratus will only gradually lift.
Surface flow will be southeast and a bit gusty today, mainly across
the ridges and some hilltops. Surface flow will shift to west as
the system exits tonight. Moderate south to southeast flow aloft
today will become moderate west to northwest as the system exits
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: Medium.
ALTERNATE SCENARIOS: Timing of precipitation and associated MVFR
to IFR conditions may vary.
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 15 16 17 18 19 20 21 22 23 00 01 02
EST 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY M L H H H L M H H H M L
HTS CONSISTENCY M H M M M H H M H H H M
BKW CONSISTENCY H H H M H M L M M M M L
EKN CONSISTENCY M M M M M M L M M M L L
PKB CONSISTENCY M M M M H H L M H M M L
CKB CONSISTENCY M H M M M L M M M M H L
AFTER 12Z WEDNESDAY...
IFR possible in possible snow showers Thursday through Thursday
night, mainly in the mountains,
WV...Freezing Rain Advisory until 7 PM EST this evening for