Area Forecast Discussion
Issued by NWS Charleston, WV-- Highlight Changed Discussion --
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FXUS61 KRLX 280722
Area Forecast Discussion
National Weather Service Charleston WV
322 AM EDT THU JUL 28 2016
A weak east to west frontal boundary just to our north will
move little. Several disturbances and copious moisture will bring
heavy rainfall potential into the weekend.
.NEAR TERM /THROUGH TONIGHT/...
Sent an update per latest radar and lightning data showing
clusters of showers and storms moving north across the KY and wV
border. Increase PoPs to likely. Additional showers or storms
would develop overnight into the morning hours. A Flash Flood
Watch remains in effect for portions of northeast KY, southeast
OH and WV through 12Z Friday.
Previous discussion below...
745 PM UPDATE...
One band of showers and storms currently over E KY will shift
into S WV and SW VA over the next couple of hours while
dissipating as it does so. This disturbance passes to the east
this evening while the quasi zonal flow becomes more amplified and
out of the SW toward morning. This will allow a potent wave to
track into the area for Thursday along with copious amounts of
moisture. There still exists some discrepancy in the near term and
short term models regarding the heavies axis of qpf with this
feature with some taking it more into SE OH and along the OH River
and others focused further SE. Complicating matters is extent of
convection tomorrow which would enhance rainfall amounts. There
should be quite a bit of cloud cover to limit heating but with the
tropical atmosphere we are in it still looks like a general 1 to 2
inches with isolate higher amounts possible along wherever the
main qpf axis sets up and in any convection. Flash flood watch
will continues as is.
PREVIOUS DISCUSSION BELOW...
Broad and very moist upper level low over the southern
Mississippi Valley this afternoon...having pw`s above 2
inches...will move northeast later tonight and Thursday. There is
model consensus of tracking the system across our area and
targeting our area with heavy rain potential Thursday...a general
1 to 2 inch swath with locally heavier amounts in any training of
storms. Enough instability available for thunderstorms despite
the expected cloud shield...but does not look like a severe
thunderstorm threat scenario at this time. Thus...with much of the
area nearly saturated from yesterday...have issued an FFA with
this system from 12z Thursday to 12Z Friday for a good part of our
area. Have started conservatively...omitting parts of southeast
Ohio and far southeast portions of the area from the watch based
mainly on not receiving yesterdays rainfall. Otherwise any
convection this afternoon...mainly in the south...will wane fairly
early this evening with loss of heating. As the above mentioned
system approaches...there will be a large shield of clouds ahead
of it. Given that this system is very nearly tropical in
nature...it probably will not be as dependent on solid diurnal
heating to generate convection as we are used to. Thus...more
confidence in issuing the FFA.
It will continue to be warm and muggy tonight with the high
dewpoints and increasing clods overnight. For Thursday...somewhat
cooler only because of the clouds and showers and storms...but
quite muggy. Highs in the lower to mid 80s.
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
One surface wave will be departing to our east to start the
period...likely leaving a boundary somewhere in the vicinity.
However, not much else to kick things off -- slightly rising 500mb
heights and the next surface wave still to our west. So, have
generally decreasing POPs Friday into Friday night but never went
with a dry forecast due to the boundary and plenty of low level
Better chance of showers and thunderstorms on Saturday as another
surface wave slides by. This feature is rather messy in the
models, but still kept likely POPs across much of the northern and
central CWA for now. May be able to fine tune as details resolve.
Will have to continue watch for water issues, as precipitable water
oscillates from 1.5 to around 2 inches with each wave. Will
mentioning HWO, but not enough confidence to commit to any specific
areas to extend the flash flood watch. A lot of it will depend on
which areas receive the most rain today into tonight. Expect
abundant clouds through the period, so instability will be somewhat
limited and not seeing any organized severe threat.
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Weather looks to remain unsettled for most of the extended period as
additional disturbances move through the region. Drier weather
possible early to mid next week as upper ridging strengthens across
the region. Another front late week.
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
VFR/MVFR conditions will prevail outside showers or storms
overnight. Radar and lightning data indicate clusters of showers
and storms moving north northeast across the KY and WV border.
Although some areas show diminishing lightning, some storms could
move over WV and southeast OH overnight producing mvfr/ifr
conditions along their path. Areas of IFR patchy fog will develop
over areas that receive rainfall and along some river valleys.
IFR conditions is expected in dense fog, low stratus along river
valleys through 12Z. Any fog will lift into low status by 13Z.
After 12z Thursday...organized shield of showers and storms
spreading northeast across the area with conditions lowering to
MVFR/IFR especially in convection.
CONFIDENCE AND ALTERNATE SCENARIOS...
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY...
FORECAST CONFIDENCE: Medium.
ALTERNATE SCENARIOS: Fog potential tonight depends greatly on
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 THU 07/28/16
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY L L L L L L L M M M M M
HTS CONSISTENCY L L L L L L L M M M M M
BKW CONSISTENCY H H H H H M L H M M M M
EKN CONSISTENCY M L L L L L M M H H H H
PKB CONSISTENCY M M L L L L M M H H H M
CKB CONSISTENCY M M L L L L M M H H H H
AFTER 06Z FRIDAY...
IFR conditions in showers and thunderstorms through Thursday
WV...Flash Flood Watch from 8 AM EDT this morning through Friday
morning for WVZ005>009-013>020-024>032-036>040-046-047.
OH...Flash Flood Watch from 8 AM EDT this morning through Friday
morning for OHZ083-085>087.
KY...Flash Flood Watch from 8 AM EDT this morning through Friday
morning for KYZ101>103-105.