Area Forecast Discussion
Issued by NWS Charleston, WV

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000
FXUS61 KRLX 191054
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
554 AM EST Sun Nov 19 2017

.SYNOPSIS...
Much colder air arrives first thing this morning. High pressure
Monday through Tuesday. Cold front crosses Tuesday night. High
pressure again through Thanksgiving. Cold front crosses Saturday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 240 AM Sunday...

Cold frontal boundary to the east of the CWA, with -shra and gusty
winds continuing behind the front. Behind the front, colder air
filtering into the region, and expecting temperatures to fall
throughout the morning and possibly early afternoon, before holding
somewhat steady. The gusty winds will continue for most of the day
with tight pressure gradient and caa occurring.

As the colder air filters in, any lingering rain showers will
gradually change over to either a mix or light upslope snow showers
across the northern mountains. There still looks to be an uptick in
the precipitation later this afternoon and evening, as a series of
upper disturbances move across the north. This will lead to an
increasing chance of accumulating snows across the mountains, with a
rain/snow mix expected across much of southeast Ohio and northern WV
zones, before transitioning to all snow overnight. Still looking at
little to no snow accumulation across the northern WV lowland
counties, with a general 1 to 4 inches across Randolph, Webster, and
Pocahontas counties, with the higher amounts in favored upslope
areas. Will continue the WSY across the higher terrain of these
counties.

Snow will gradually taper off towards morning as high pressure
builds into the region from the west, and flow becomes less
favorable.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
As of 240 AM Sunday...

High pressure passes south of the area Monday, and then moves
east, as upper level flow backs. This results in deep layer
southwest flow Tuesday, and hence milder weather. A cold front
reverses this trend, as it slips through Tuesday night into
early Wednesday morning. The associated upper level short wave
trough passes north of the area, leaving the area on the
anticyclonic shear side of the jet stream. This, along with
little inflow ahead of the front, spells little precipitation
associated with this front. Continued the slight chance in the
mountains for Tuesday night.

High pressure builds in Wednesday and Wednesday night, bringing
a return to the dry, chilly weather, although clouds associated
with another upper level short wave trough approaching from the
west, and low pressure passing south of the area, will limit
radiative cooling somewhat Wednesday night.

No deviations needed from central guidance temperatures, other
than to lower a bit Monday morning.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
As of 240 AM Sunday...

High pressure will dominate Thursday through friday, with more
dry, chilly weather, even as an upper level short wave trough
crosses.

A stronger short wave trough deepens as it crosses the area
Saturday, driving a cold front through. Despite the
amplification of the trough, only the small chance for light
precipitation is forecast for Saturday into Saturday night, with
little inflow ahead of the front Saturday. Models continue in
good agreement on this system, with faster timing compared with
the previous forecast.

No changes were needed to central guidance temperatures and dew
points, which trended lower at the end, but still a little
above deterministic guidance.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
As of 550 AM Sunday...
12Z Sunday through 12Z Monday...

Widespread MVFR conditions across the area, with gusty
northwesterly winds. Expect sustained winds in the teen kts, with
gusts in the 20 kt range across the lowlands, and the 30 to 40
kt range across the higher terrain.

After 18-21Z on Sunday, some general improvement from west to
east to VFR as surface high pressure builds into the region.
Bulk of gustier winds will generally drop off after 22Z, but
will continue across the higher terrain and parts of northern WV
for most of the TAF period.

Otherwise, expect periods of rain and snow showers, particularly
across the mountains, parts of southeast Ohio, and northern WV,
with areas of MVFR and local IFR conditions.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...

FORECAST CONFIDENCE: Medium

ALTERNATE SCENARIOS: Timing of improvement to VFR on Sunday
could vary from forecast. Conditions could be worse in
mountainous counties than currently forecast, particularly in
snow showers.

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.

DATE               SUN 11/19/17
UTC 1HRLY       10   11   12   13   14   15   16   17   18   19   20   21
EST 1HRLY       05   06   07   08   09   10   11   12   13   14   15   16
CRW CONSISTENCY  M    H    H    H    H    H    H    M    M    M    L    M
HTS CONSISTENCY  H    M    M    M    M    H    H    H    M    H    L    L
BKW CONSISTENCY  H    H    L    H    H    M    M    M    M    M    L    L
EKN CONSISTENCY  L    L    L    M    L    L    L    L    M    L    L    L
PKB CONSISTENCY  H    M    M    H    H    H    M    H    H    M    L    M
CKB CONSISTENCY  H    H    H    H    H    H    M    H    L    L    L    L

AFTER 12Z MONDAY...
No widespread IFR conditions expected.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Wind Advisory until noon EST today for WVZ520-522>524-526.
     Wind Advisory until 10 AM EST this morning for WVZ032-039-040-
     521-525.
     Winter Weather Advisory until 3 AM EST Monday for WVZ522-523-
     526.
OH...None.
KY...None.
VA...None.

&&

$$
SYNOPSIS...TRM/SL
NEAR TERM...SL
SHORT TERM...TRM
LONG TERM...TRM
AVIATION...SL


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