Area Forecast Discussion
Issued by NWS Charleston, WV

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426
FXUS61 KRLX 062034
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
334 PM EST Tue Dec 6 2016

.SYNOPSIS...
Low pressure crosses 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 WEDNESDAY/...
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
morning.

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 NIGHT THROUGH FRIDAY NIGHT/...
As of 315 PM Tuesday...

Main feature in the short term will the arrival of modified arctic
air. The models continue to waffle on the extent of development of
a mid level wave Thursday, with all showing little to no
development such that low pops currently may be able to be lowered
even more. Good CAA commences Thursday night with H85 temps
lowering into the -12 to -14C range. This combined with orographic
contributions should be able to squeeze out some mountain snow
showers and flurries elsewhere despite rather meager moisture
depth. This should continue for Friday as well though any lakes
contribution should stay north of the area. Only expecting some
minor accumulations in the mountains and perhaps a dusting here or
there in the lowlands. Elected to beef up the sky grid from what
the Blender provided as well as lowering highs from the Blender.
Think most if not all places will stay below freezing for highs. A
gusty WNW wind will bring some low wind chills especially in the
mountains. Snow showers and flurries will wane Friday night but
clouds should linger.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 320 PM Tuesday...

Increasingly milder air will filter into the area this weekend,
but still will be rather chilly on Saturday with sunshine finally
returning to the area. Milder air will work into the area in
earnest Sunday and Monday ahead of the next system with showers
and perhaps a mix at onset working in Sunday night and Monday.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
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
tonight.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z 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       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    M    H    H    H    H    M
HTS CONSISTENCY  H    H    M    H    M    H    H    H    H    H    H    M
BKW CONSISTENCY  M    L    L    L    M    M    M    H    M    M    M    L
EKN CONSISTENCY  M    H    L    L    M    M    L    L    L    H    L    M
PKB CONSISTENCY  L    M    M    M    M    H    H    H    H    H    H    M
CKB CONSISTENCY  H    H    H    H    H    M    M    H    H    M    M    L

AFTER 18Z WEDNESDAY...
IFR possible in possible snow showers Thursday through Thursday
night, mainly in the mountains,

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Freezing Rain Advisory until 7 PM EST this evening for
     WVZ523>526.
OH...None.
KY...None.
VA...None.

&&

$$
SYNOPSIS...ARJ/30
NEAR TERM...ARJ
SHORT TERM...30
LONG TERM...30
AVIATION...ARJ



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