Area Forecast Discussion
Issued by NWS Charleston, WV

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FXUS61 KRLX 230529
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
129 AM EDT Fri Jun 23 2017

.SYNOPSIS...
Remnants of Cindy and a cold front to provide rounds of heavy
rain through Friday night. Cooler Sunday through Tuesday, with
upper level disturbances possibly providing a few light showers.

&&

.NEAR TERM /THROUGH TODAY/...
As of 100 AM Friday...

Adjusted PoPs according to latest radar images and removed
thunder through 12Z. Rest of forecast remains on track.

As of 745 PM Thursday...
Tweaked hourly temperatures and wind grids. Otherwise, previous
forecast appears to be on track.

As of 215 PM Thursday...

First round of showers and storms moving generally northeastward
at the moment, pushing into the Tug Fork Valley along the nose
of a low level 850mb jet running around 50kts. This will be a
slow to push northward through the evening, essentially priming
the surface and triggering the potential for flooding later on
in the forecast. Tropical moisture from Cindy still the main
issue as it stream in the low and mid levels, and have PWATs 2
to 3 standard deviations above normal. Bulk of the rain
organizing along the frontogenesis bands will take place in
OH/WV northern panhandle/PA, clipping our northwestern zones in
southeastern Ohio heading into Friday.

Given the set up, cannot ignore the severe threat tomorrow,
that still has more questions than answers right now. The low to
mid tropospheric flow setup is favorable, but surface based
instability is in question given clouds, although some breaks in
the cover and insolation could provide a short window for
storms to form well ahead of the cold front. Water loading and
less than favorable mid level lapse rates could also hinder
severe threats, but again, the increasing flow may win out in
this situation.

Heaviest rain is slated for the short term. Flash flood watch
issued, however, with thunderstorm potential this evening and
Friday.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/...
As of 255 PM  Thursday...

Remaining circulation associated with Cindy will be passing
over the forecast area Friday night. NCEP 12Z models along with
the ECMWF are in pretty close agreement in terms of their mass
and synoptic fields and show the circulation passing by around
06Z Saturday. Canadian NH taking main circulation a bit further
south into VA. Still noted considerable differences in QPF
output and associated moisture fields in the models. For this
forecast cycle, we bisect max QPF axis on Friday night across
central WV, with the higher amounts painted across the southern
coalfields. The rainfall rate maxima will occur in association
with front as it passes through. Flash Flood watches posted
since tropical downpours combined with already wet soils from
previous rains will make water problems strong possibility.

Flood potential will remain with us on Saturday, and depending
on where heaviest precipitation falls, could mainly be relegated
to the main stem rivers as headwater runoff moves down to the
larger river channels.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
As of 255 PM Thursday...

General troughiness will be in place over the Eastern United
States with weaker shortwaves rotating through. Atmospheric
columns will be relatively dry in comparison to previous
tropical airmass that have been dominating the weather pattern
for our area. As each of these disturbances rotate through, we
could see some light shower development. Went with blends for
temps and pops.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
As of 125 AM Friday...

Radar images show a batch of MVFR/IFR showers moving northeast
across PKB, CKB and EKN. Brief IFR conditions could be possible
under heavier rain. Rainfall activity will diminish from
southwest to northeast overnight.

Models are in agreement in bringing a wave of showers and
thunderstorms around 18-20Z Friday, particuarly across
southeast Ohio, shifting eastward across the area towards 00Z
Saturday and beyond. Expect heavy downpours, IFR/LIFR
conditions, and the possibility of strong damaging winds.

Most of the area is under a slight risk for severe
thunderstorms. Expect amendment will be required especially
winds and visibility.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SATURDAY...

FORECAST CONFIDENCE: High

ALTERNATE SCENARIOS: Timing and duration of any MVFR conditions
overnight may vary from forecast. Timing and development of tsra
on Friday may vary from forecast.

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                                             FRI 06/23/17
UTC 1HRLY       03   04   05   06   07   08   09   10   11   12   13   14
EDT 1HRLY       23   00   01   02   03   04   05   06   07   08   09   10
CRW CONSISTENCY  H    H    H    H    H    H    H    L    H    L    L    L
HTS CONSISTENCY  H    M    M    H    H    H    H    H    H    L    H    M
BKW CONSISTENCY  H    H    M    H    H    H    L    H    M    M    M    L
EKN CONSISTENCY  H    H    M    M    H    H    H    H    H    H    M    M
PKB CONSISTENCY  H    M    L    M    L    H    H    H    M    M    H    L
CKB CONSISTENCY  H    H    M    M    M    L    H    H    H    H    H    L

AFTER 06Z SATURDAY...
IFR possible in showers and thunderstorms Friday night.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Flash Flood Watch through late tonight for WVZ005>011-013>020-
     024>034-039-040-515>526.
OH...Flash Flood Watch through late tonight for OHZ066-067-075-076-
     083>087.
KY...Flash Flood Watch through late tonight for KYZ101>103-105.
VA...Flash Flood Watch through late tonight for VAZ003-004.

&&

$$
SYNOPSIS...RPY/26
NEAR TERM...ARJ/SL/26
SHORT TERM...KMC
LONG TERM...KMC
AVIATION...ARJ



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