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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 132322
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
722 PM EDT Sun Aug 13 2017

.SYNOPSIS...
Unsettled weather arriving Monday. Dry weather on Wednesday
followed by more unsettled weather into the weekend.

&&

.NEAR TERM /THROUGH MONDAY/...
-- Changed Discussion --
As of 705 PM Sunday...

Biggest challenge in the forecast this evening is timing the
advection of high level moisture into the area. LAV guidance is
now jumping on board with this cloud cover preventing sustained
valley fog overnight.

As of 155 PM Sunday...

While we bask in nice weather today, attention in the near term
focuses on the return of showers Monday. The convective complex
currently over the southern MS Valley will move into the TN
Valley tonight and across portions of the southern Appalachians
Monday. Meanwhile, additional forcing will arrive courtesy of an
amplifying s/w trof moving through the region. The end result is
showers moving in Monday morning and increasing in coverage
during the afternoon. After coordinating with surrounding
offices, I have coded up likely pops generally along/east of the
US 119/I 79 corridor. Pops tail off considerably to low chance
across southeast Ohio. There will be some instability across
southwest Va in the afternoon with a few storms possible. High
temperatures were adjusted downward to reflect more of an
unsettled day east of the Ohio River, with the eastern slopes
even cooler with the development of low level wedge on southeast
flow.
-- End Changed Discussion --

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
As of 310 PM Sunday...

Weak high pressure will eventually take control of the weather
across the region. As a result, shower and thunderstorm chances
mainly in the mountains for Monday night and Tuesday will end by
Tuesday night.

Generally used a consensus of model data for lows Monday night
and Tuesday night as well as highs for Tuesday.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 310 PM Sunday...

Models suggest southwest flow will develop with several mid-
level disturbances progged to impact the region. As a result...
an unsettled pattern will become established beginning Wednesday
night.

Have likely Pops for parts of our area Thursday through Friday
with some guidance suggesting likely Pops should continue into
Saturday. However because of uncertainty, have kept Pops as
chance.

Cold front pushes southeast on Saturday with precipitation
chances ending from the northwest.

Once again, used a consensus of model data for low and high
temperatures.

&&

.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --
As of 720 PM Saturday...

High level moisture, and later, mid level moisture, brings cloud
cover into the area after 06Z tonight, preventing a sustained
period of valley fog development. Have some reduced visibilities
in the TAFs at a few locations early in the overnight period,
but coming up to MVFR/VFR late once the sky becomes BKN/OVC.

The southern mountains will experience southeast upslope
conditions as moist upslope flow seen at 925mb take hold around
12Z. Bring the ceilings to 1-2kft through around 18Z, lifting
after this time frame.

Showers move in west to east after 11Z Monday. MVFR prevails.

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

FORECAST CONFIDENCE: Medium to high.

ALTERNATE SCENARIOS: Should timing of clouds be delayed, then
river valley fog will be more prevalent at the terminals.

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       22   23   00   01   02   03   04   05   06   07   08   09
EDT 1HRLY       18   19   20   21   22   23   00   01   02   03   04   05
CRW CONSISTENCY  H    H    H    H    H    H    H    H    M    H    L    L
HTS CONSISTENCY  H    H    H    H    H    H    H    H    M    M    L    L
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    L    L
EKN CONSISTENCY  H    H    H    H    H    M    M    L    L    M    L    L
PKB CONSISTENCY  H    H    H    H    H    H    H    H    M    L    L    L
CKB CONSISTENCY  H    H    H    H    H    H    H    M    M    M    L    L

AFTER 00Z TUESDAY...
IFR valley fog possible early Tuesday morning.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...JSH/30
NEAR TERM...30/26
SHORT TERM...JSH
LONG TERM...JSH
AVIATION...26