425
FXUS61 KRLX 191516
AFDRLX

AREA FORECAST DISCUSSION
National Weather Service Charleston WV
1016 AM EST Sun Jan 19 2025

.SYNOPSIS...
Snow moving into the area early this morning becomes heavy at
times today. Snow becomes increasingly showery tonight before
ending Monday morning. Very cold Monday through mid-week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1000 AM Sunday...

Inherited package is in really good shape this morning with no
substantial changes needed at this time.

Heavier banding of snow just crossing the OH River and into the
western Metro Valley at this hour has produced localized
snowfall rates up to 1"/hr. Expect this feature to continue to
progress slowly to the east producing the bulk of the synoptic
portion of this event`s snow through the the remainder of this
morning and into early this evening. As mentioned below, after
the exit of the synoptic portion of this event, we will
transition into more a showery/squally period late this evening
and into the early overnight as parcel trajectories become more
favorable for upstream moisture contribution from the Upper
Great Lakes with arrival of the arctic front.

As air temperatures plummet tonight and road skin temperatures
rapidly cool, typical rock salt used for ice abatement will
rapidly lose effectiveness (it takes around 10 times as much to
melt the same amount of ice at 10 degrees vs 30 degrees) which
could result in a flash freeze even on treated surfaces where
they remain wet. Travel is highly discouraged in both the
heavier snow bands today, and overnight with plunging
temperatures amid snow showers and squalls.

As of 640 AM Sunday...

Forecast on track, with snow coverage and intensity increasing
across the middle Ohio Valley early this morning.

As of 435 AM Sunday...

A snowstorm will impact the area today, and then an arctic cold
front blasts through the area tonight.

Precipitation developing over central portions of the forecast area
in a southwest-northeast fashion early this morning was in response
to a wave developing over the Carolinas, near a front southeast of
the forecast area. The precipitation will quickly become all snow
while becoming more widespread through daybreak.

Above a low level cold advection regime, forcing from the
approaching mid/upper-level short wave trough instigating the
baroclinic wave development crosses the forecast area mid morning
through mid afternoon, maximizing lift in the favored dendritic
growth temperature zone, -12 to -18C. This is when the snow will be
moderate to heavy at times.

Travel can quickly become treacherous during the daybreak and early
daylight morning hours this morning, with conditions only
deteriorating through the day, including low visibility.

The wave moves off to the east this evening, and snowfall diminishes
from west to east. However, an arctic cold front crossing the area
tonight could instigate heavy, gusty snow showers or even snow
squalls, given a forecast snow squall parameter axis of 1 to 3
units coincident with the leading edge of the arctic air
crossing the forecast area tonight. Post- storm treated roads
can become snow covered again, with brief low visibility beneath
these snow showers.

Lingering snow showers and flurries than become increasingly
confined to the mountains overnight, but gusty west northwest winds
develop quickly behind the arctic front. Winter Weather Advisories
looked good except to add Morgan County in east-central Ohio, and
upgrade the Winter Weather Advisory in Dickenson County, Virginia to
a Winter Storm Warning. The rest of the Winter Storm Warnings looked
good.

Temperatures gradually fall into and through the 20s this morning,
and will be steady or continuing to fall slowly through the 20s this
afternoon and evening, and then plummet into the 10s and then single
digits behind the arctic front tonight, even below zero across the
higher mountains terrain by dawn Monday. Wind chill indices by dawn
fall into the single digits below zero across the lowlands, and 10s
and 20s below zero across the higher mountainous terrain.

Upgraded more of the Extreme Cold Watch to an Extrema Cold Warning
for the remainder of the northern and the central mountains of WV,
and converted the Extreme Cold Watch to a Cold Weather Advisory
across the remainder of the area, all starting just after midnight
tonight, behind the arctic front. In general, still expecting 1 to 4
inches for the Winter Weather Advisory area, 3 to 6 inches for the
Winter Storm Warning across our lower terrain, and 5 to 9 inches
across the higher mountainous terrain.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 300 AM Sunday...

Kept previous forecast chances of precipitation for Monday as
cold air advection still squeezing the soundings and the
National Blend of Models was way too low. In cold air advection
and arctic air, flurries usually fall from any cloud, so
included flurries for Monday anywhere sky cover was 30 percent
or higher.

Models are showing an upper level disturbance on Tuesday moving
across the area. Once again, in the cold air, these disturbances
tend to produce light snow/flurries quite easily, so have
increased chances of precipitation area wide.

A surface arctic high pressure system builds over the area
Monday night and remains into Wednesday. This should set up the
coldest nights of the season for Sunday, Monday and Tuesday
nights, with much of the area in the lower single digits or
below zero degrees. Have issued cold weather advisories and
warnings area wide for Sunday night into Monday. Expect
additional cold weather headlines for the late night/morning
hours later in the week. Trimmed the Extreme Cold Watch to just
the higher elevations of the West Virginia mountains for
Tuesday night through Thursday morning, where warning criteria
is the most likely to occur.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 300 AM Sunday...

Models show a high pressure system over the area for Wednesday,
providing dry weather into Thursday. Cold weather headlines may
still be needed for the higher elevations of the northern West
Virginia mountains into Thursday morning. As the high slides
eastward on Thursday, temperatures moderate.

Models agree a bit better on Friday with an upper level trough
moving through, but still disagree on the details of this
system.

A high pressure system returns for Saturday, providing dry
weather with temperatures moderating even more.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
As of 105 AM Sunday...

A snowstorm will impact the area today, and then an arctic cold
front blasts through the area tonight.

The area remains in an overcast and damp regine overnight,
behind a a cold front just east of the area. IFR ceilings remain
in place all but PKB which has a low end MVFR ceiling, with IFR
to VLIFR visibility in the mountains, worst at BKW, and MVFR
visibility near the mountains, CKB and CRW, in spotty light
precipitation. These conditions will predominate into the pre-
dawn hours.

The snowstorm was developing over the area early this morning,
in response to a wave forming along the front, and temperatures
subfreezing areawide. IFR conditions in snow will develop
12-14Z, with PKB already IFR in a developing band along the Ohio
River, CRW in IFR mist in light snow, and BKW in dense freezing
fog and light snow. IFR to VLIFR conditions at times in
predominantly moderate to heavy snow, as opposed to mist or fog,
from mid to late morning through mid to late afternoon.

Ceilings and visibility will improve to low-end MVFR at times
this evening in snow showers as the wave exits. However, an
arctic cold front moving through tonight, 02Z-07Z west to east,
could bring brief, gusty VLIFR snow showers. Improving
conditions will follow in the predawn hours as snow showers fade
to flurries west to east in the dry arctic air.

Light northerly flow this morning will freshen a bit and become
a bit gusty at times this afternoon, and then back to the
northwest with gusts to 15 to 20 kts tonight, a bit higher at
BKW, and higher in a gusty snow shower at any location tonight,
as the aforementioned arctic front blasts through.

Light southwest to variable flow aloft this morning will become
light northwest this afternoon, and then moderate northwest
tonight.

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


FORECAST CONFIDENCE: Medium.

ALTERNATE SCENARIOS: Onset and persistence of IFR to VLIFR
ceilings and visibility in snow today may vary from the
forecast. Timing of slowly improving conditions tonight may
vary, including possible interruptions by heavy, gusty snow
showers with the arctic front.

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

AFTER 12Z MONDAY...
No widespread IFR conditions expected at this time.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Winter Weather Advisory until 8 AM EST Monday for WVZ005>011-
     014-017-019-020-524.
     Cold Weather Advisory from 1 AM to 3 PM EST Monday for
     WVZ005>011-013>020-024>034-524.
     Winter Storm Warning until 8 AM EST Monday for WVZ013-015-016-
     018-024>034-039-040-515>523-525-526.
     Extreme Cold Warning from 1 AM to 4 PM EST Monday for WVZ039-
     040-515>521-525.
     Extreme Cold Watch from late Tuesday night through Wednesday
     morning for WVZ516-518-520.
     Extreme Cold Warning from 10 PM this evening to 9 AM EST
     Tuesday for WVZ522-523-526.
     Extreme Cold Watch from Tuesday morning through Thursday
     morning for WVZ522-523-526.
OH...Winter Weather Advisory until 8 AM EST Monday for OHZ067-075-
     076-083>087.
     Cold Weather Advisory from 1 AM to 3 PM EST Monday for OHZ067-
     075-076-083>087.
     Cold Weather Advisory from 1 AM Monday to noon EST Tuesday for
     OHZ066.
KY...Winter Weather Advisory until 8 AM EST Monday for KYZ101>103-
     105.
     Cold Weather Advisory from 1 AM to 3 PM EST Monday for
     KYZ101>103-105.
VA...Cold Weather Advisory from 1 AM to 3 PM EST Monday for VAZ003-
     004.
     Winter Storm Warning until 8 AM EST Monday for VAZ003-004.

&&

$$

SYNOPSIS...RPY/TRM
NEAR TERM...TRM/JP
SHORT TERM...RPY
LONG TERM...RPY
AVIATION...TRM