Area Forecast Discussion
Issued by NWS Charleston, WV

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000
FXUS61 KRLX 220001
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
801 PM EDT Sat Oct 21 2017

.SYNOPSIS...
High pressure continues through Sunday. A strong cold front and
low pressure system crosses early next week, with much cooler
weather midweek.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 200 PM Saturday...

Intervals of cirrus through Sunday as high pressure shifts to
the east. Patchy dense river valley fog overnight, but thinking
the combination of cirrus and boundary layer winds will keep
much of it confined to the mountain valleys.

The smoke plume from the large industrial site fire in
Parkersburg should back more toward the north overnight and
perhaps into the city of Parkersburg. Should more decoupling
occur than forecast, poor ventilation rates and lack of
dispersion overnight could result in reductions in visibility.
Having said that, this is a low confidence scenario, especially
considering the uncertainty regarding how much smoldering will
exist overnight.

Overnight lows were hedged a few degrees below guidance with
highs tomorrow on the warm side of the guidance envelope.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
As of 235 PM Saturday...

Models showing an upper level low pulling moisture into the region
on Monday. Still some timing differences in the timing of the rain
bands with this system, but the overall pattern is in fairly good
agreement. Cold front should push through late Monday/Monday
evening.

Some models showing rainfall amounts from 0.75 to 1.50 inches, while
others show 0.75 to 2.50 inches. With the area being dry recently,
flash flood guidance is generally in the 2.25 to 3 inch range in 6
hours, so should be able to handle the rainfall. Will keep an eye on
this however.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 235 PM Saturday...

Cooler air will move into the area behind the cold front Tuesday and
Wednesday as an upper level trough moves over the area. This trough
will also provide some moisture and lift, allowing for a chance of
showers. With colder air aloft, could see some snow flakes in the
higher elevations of the northern WV mountains.

High pressure will build over the area for Thursday and Friday.

Another strong cold front can then be expected over the weekend.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
00Z Sunday thru 00Z Monday...
As of  PM Saturday...

Generally, VFR amid passing cirrus tonight. Smoke plume from
fire just south of PKB had shifted east of the terminal and
lifted late Saturday afternoon as winds had become southwesterly
and mixing occurred. The plume will likely shift back
northwestward and lower across the area tonight as winds turn
very light southeasterly. Should this occur, vsby and/or cig
restrictions may be realized given the lowering ventilation rate
and developing low level inversion. So, for now, will just
touch on light VFR smoke for PKB overnight due to very low
confidence on impact of and duration of this plume. Otherwise,
boundary layer winds overnight should keep dense fog out of the
taf sites, save of course for KEKN 10Z-13Z where LIFR fog is
expected under the inversion.

VFR conditions on Sunday with passing cirrus and sw winds 5 to
10 kts.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z MONDAY...

FORECAST CONFIDENCE: High except at PKB.

ALTERNATE SCENARIOS: Smoke may restrict vsby and/or cigs more
than forecast at PKB tonight.


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 10/22/17
UTC 1HRLY       00   01   02   03   04   05   06   07   08   09   10   11
EDT 1HRLY       20   21   22   23   00   01   02   03   04   05   06   07
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
EKN CONSISTENCY  H    H    H    H    H    H    H    H    H    M    L    M
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M

AFTER 00Z MONDAY...

Heavy rain at times Monday and Monday night could bring IFR
conditions.

&&

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

&&

$$
SYNOPSIS...RPY/JMV/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...RPY
AVIATION...JMV



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