Area Forecast Discussion
Issued by NWS Charleston, WV-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KRLX 221735
Area Forecast Discussion
National Weather Service Charleston WV
135 PM EDT FRI JUL 22 2016
Low level moisture on the increase today. Weak disturbances drop
southeast today and Saturday. Front stalls in Upper Ohio Valley
.NEAR TERM /THROUGH TONIGHT/...
Latest radar mosaic shows broken line of showers/storms has pushed
into portions of Perry County at this time. Short-term models
suggest that these storms should weaken as they continue to push
southeast. However...they appear to be maintaining their intensity
Have tweaked PoP grids...especially across southeast Ohio...to
reflect my thinking that these storms should continue to push
southeast for a few hours before weakening.
Otherwise...nothing more than tweaks are needed.
Upper clouds streaming through early this morning associated with
an MCS to our west.
Dirty ridge just to our west through the period, and will have
some week upper disturbances drop down the eastern side of the
ridge today into tonight. With these, have isolated to scattered
showers and thunderstorms...with the highest POPs across the Mid
Ohio River Valley. The amount of instability today will depend
on how thick the high clouds remain this morning. There is
definitely a good deck of cirrus to our northwest associated with
the MCS. NAM does show recovery to 1000-2000 j/kg CAPE this
afternoon across western half of CWA, which would be enough for
some taller storms capable of gusty winds. The atmosphere should
be warm enough to limit hail production. Shear is very weak so
storms should be rather pulsey and not become well organized.
Precipitable water values top 2 inches along and west of the Ohio
River, indicating downpours are also possible in any
Blended ECMWF mos into previous forecast, with only minimal
changes. Mainly a bit warmer overnight. Today will be a warm day,
with increasing dewpoints. Heat indices top out just below
advisory criteria this afternoon -- in the mid and upper 90s
across the lowlands.
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
The heat wave will continue this weekend with temperatures
reaching the lower 90s. Models show a dry column through the
period with some moisture at the mid levels and high sfc CAPE
values. Can no ruled out low chance for showers and storms by
A weak cold front becomes stationary in the vicinity to our
north. Convective complexes can develop under northwest flow.
Remnants of these complexes can dig southeast while diminishing in
intensity. This will bring debris clouds to the area. Despite the
clouds, temperatures will climb again Sunday mainly lowlands.
Moisture and hot temperatures can make heat index to climb into
the 100s this weekend.
Went with the superblend guidance for temperatures through the
period. Continued advertising possible heat advisories for the
.LONG TERM /MONDAY THROUGH THURSDAY/...
It will turn more unsettled early next week with the arrival of a
frontal boundary coupled with a s/w trof passage. These features
will make a run toward the area later on Monday with convection
chances increasing thru the afternoon and especially into the
evening hours. The upper ridge will flatten as the overall pattern
turns more zonal with generally weak flow through the atmosphere.
This will keep the unsettled pattern going thru Tuesday as the the
front will be in no hurry to push through. With the light flow and
high pwats...some slow moving downpours are in the cards. The
front finally gets a nudge to the S by Wednesday with mid level
drying spreading into the area keeping afternoon shra/tsra chances
confined over S WV/SW VA in the better moisture.
Temps will gradually ease back closer to normal levels
midweek...likely ending the heat wave over portions of the area Monday.
.AVIATION /18Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --18Z FRIDAY THROUGH 18Z SATURDAY...
Latest radar mosaic continues to indicate scattered showers and
storms with MVFR...local IFR...conditions were pushing across
southeast Ohio. Outside of the area...vfr conditions prevailed.
An upper level disturbance will push southeast into the nighttime
hours. As a result...the storms should continue to move/develop
southeast during the afternoon hours. The best chance will
be along and west of the Ohio River, and have continued VCTS on
the PKB and HTS TAFs into the evening hours.
Models still fairly insistent on fog formation tonight, but think
there will be enough remnant clouds around to allow for dense fog
formation. Have generally gone with 6sm br between 08Z and 12Z
everywhere...with some 3-5sm br in favored river valleys...at
places like CRW/EKN.
VFR conditions are expected after 13Z...with isolated storms
possible after 15Z.
CONFIDENCE AND ALTERNATE SCENARIOS...
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SATURDAY...
FORECAST CONFIDENCE: Medium.
ALTERNATE SCENARIOS: May need to expand VCTS this afternoon and
evening. Dense river valley fog may form 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.
UTC 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
EDT 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY M M H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L L M H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z SATURDAY...
IFR possible in thunderstorms late Monday.
-- End Changed Discussion --