National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 212322
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
722 PM EDT Wed Jun 21 2017

.SYNOPSIS...
Weak disturbance this afternoon with a shower possible north.
Tropical moisture to bring heavy showers and thunderstorms to
end the work week. Cooler to start next week.

&&

.NEAR TERM /THROUGH THURSDAY/...
As of 645 PM...

Showers that formed across southeastern Ohio this evening have
drifted southward into parts of West Virginia, and increased
pops across these areas for the next few hours to reflect this.

As of 210 PM Wednesday...

Weak mid level vort max crossing northern portions of our area
this afternoon and evening will bring a few showers and
possibly a storm north. As this upper feature moves away this
evening and with loss of heating, most convection will end. East
to west frontal system dropping southward will stall just to
the north of our area early tonight and then shift back north as
a warm front late tonight and Thursday. Just a slight chance of
a shower far north tonight vicinity of the front. As this front
retreats later tonight and Thursday, tropical moisture will be
on the increase as deeper southerly flow increases, and included
a little haze in the forecast for mainly river valleys later
tonight.

For Thursday, models have PW`S reaching above 2 inches on
increasingly deep southerly flow from the tropical system
currently near the Gulf Coast. Models agree a significant piece
of energy breaks off from the tropical system on Thursday, and
this piece will lift northward well ahead of the tropical system
itself. This will bring an organized area of showers and
thunderstorms into southern portions of our area by early Thursday
afternoon, and into northern portions of our area around days
end. The bulk of the rain from this piece of energy will be just
after this period. Temperatures will continue warm on Thursday,
and it will be quite humid.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
As of 345 PM Wednesday...

Attention remains focused on interaction of a cold front approaching
from the NW and the remnants of what is currently Tropical Storm
Cindy which will be approaching from the SW. Unfortunately, models
continue to differ quite a bit on location and amount of the
heaviest rain, but confidence continues to increase in a prolonged
heavy rainfall event Thursday night through Friday night.

The first slug of tropical moisture crossing the forecast area from
SW to NE Thursday night. Have an enhanced area of POPs reflecting
this trend -- lifting through the CWA Thursday night along with a
half to three quarters of an inch of rain. Even with this first
slug models are painting different pictures on where the
heaviest rainfall will occur. The ECMWF hits NW CWA hard with
close to 2 inches, while the GFS, Canadian and NAM are more
broad with a half to one inch across the bulk of the CWA.
Trended toward this consensus with the POPs and QPF Thursday
night into early Friday.

By mid morning Friday, the initial slug of moisture should be
departing to the north. The cold front should be crossing NW Ohio and
Central Indiana, and the remnants of Cindy will be crossing
Arkansas. This should give a brief lull -- at least in heavy
rain potential -- for Friday morning. However with the
complexity and uncertainty of the situation did not get too cute
with POPs and have maintained high chance to likely POPs.

Have POPs increasing through the day Friday as the cold front gets
closer. The GFS and NAM show the front holding up some as the Cindy
remnants move through TN/KY late in the day and across the southern
coal fields of WV overnight. The ECMWF keeps the front moving
and shunts Cindy 50-100 miles farther south. While this doesn`t
seem like a significant amount, the difference between in QPF
between the NAM/GFS vs the ECMWF are large. The NAM has a run
total precip max of 5+ inches across the Coal Fields, and the
GFS has a 4-5 inch max from the Tri-State to the northern
mountains. The ECMWF on the other hand is a broad one to two
inches across the CWA through Saturday morning. And just to add
some more numbers to the mix, the Canadian is showing a general
2-3 inches across the CWA.

Opted to stay with the ongoing forecast of a broad, basin wide
2-4 inches across the CWA from late Thursday into Saturday
morning...but confidence remains on the low side. The main heavy
rain/flood threat still looks to be mainly late Friday and
especially Friday night as the cold front/remnants move
through. Cannot rule out some issues Thursday night into Friday,
depending on how efficient the initial slug showers and storms
are.

The cold front should be progressive by Saturday, exiting early to
mid morning with drier air arriving Saturday afternoon into Saturday
night.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 345 PM Wednesday...

A secondary front and the broad upper trough should move through
during the first half of next week. Have some slight chance to
chance POPs with this, with only limited moisture. Temperatures will
be running below normal during this time frame. High pressure should
settle in by mid week with dry weather to round out the
extended.

&&

.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
-- Changed Discussion --
00Z Thursday through 00Z Friday...

As of 720 PM Wednesday...

Showers across southeastern Ohio and northern and central WV,
with brief MVFR conditions, will gradually dissipate after 02Z.
There is the possibility of patchy river valley fog tonight,
mainly after 07Z, as well as across the north at sites that
received precipitation, such as PKB and CKB. Any fog that is
able to develop will dissipate after 12Z. However, no widespread
fog formation is expected due to increasing cloud cover from the
south.

Clouds will increase and lower on Thursday, but generally remain
VFR. An upper disturbance will move north through the area after
18-20Z, with showers and thunderstorms developing, particularly
across southern West Virginia, southwest Virginia, and northeast
KY. Expect brief MVFR and IFR conditions in precipitation, with
generally VFR elsewhere.

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

FORECAST CONFIDENCE: High

ALTERNATE SCENARIOS: Patchy MVFR fog does not develop tonight
due to increasing cloud cover.

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

AFTER 00Z FRIDAY...
IFR possible in showers and thunderstorms Thursday night into
Saturday.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...JMV/MZ
NEAR TERM...JMV/SL
SHORT TERM...MZ
LONG TERM...MZ
AVIATION...SL