Area Forecast Discussion
Issued by NWS Charleston, WV-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KRLX 261921
Area Forecast Discussion
National Weather Service Charleston WV
321 PM EDT TUE JUL 26 2016
A weak east to west frontal boundary continues across northern
portions of area. Next system late in the week.
.NEAR TERM /THROUGH WEDNESDAY/...
A weak but persistent east to west frontal boundary meanders back
and forth across the northern portions of the area this
period. The addition of upper disturbances riding eastward across
the area on the southern edge of westerlies and PW`s aoa 2 inches
will lend to a general unsettled pattern for showers and storms.
Will tie the best chance for convection to the favored afternoon
adn early night time frame. Have hoisted a flash flood watch most
of northern half of area through 11 pm tonight...given one well
defined vort max over southwestern Ohio and increasing area of
heavy convection well ahead of it near the frontal boundary.
Otherwise...as the vort moves east of the area tonight...expect
convection to really diminish...leaving widely scattered showers
in the north after midnight. Will do similar pops again Wednesday
with little change in the pattern.
It will continue hot and humid through Wednesday...but should be a
touch below heat advisory criteria.
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
Active weather to start the short term period...with warm and humid
conditions to persist. Stalled frontal boundary across northern
zones will lift north of the area during the day Thursday as upper
shortwave trough approaches from the west. Strong llj developing
across the region...will aid in moisture transport...with pw values
rising to over 2 inches Thursday. Wave of low pressure moving north
through the region Thursday and Thursday night...will help to
enhance precipitation...with showers and thunderstorms...with heavy
downpours expected. In addition...could see strong to severe storms
during the afternoon and evening hours on Thursday...with the
potential for stronger winds aloft to be brought down to the
surface. Will place the mention of possible water headlines for the
Thursday/Thursday night time frame. Still difficult to pinpoint any
area of heaviest precipitation/greatest threat...so will highlight
entire cwa in the hwo for now.
Additional showers and thunderstorms expected for later in the day
Friday and Friday night as an upper shortwave trough crosses the
.LONG TERM /SATURDAY THROUGH TUESDAY/...
Weather looks to remain unsettled for the first part 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.
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
18Z Tuesday thru 18Z Wednesday...
Nearly stationary east to west weak front across far northern
portions of area will continue thru period.
Thru 02z...Outside of convection...SCT-BKN 2000-3000 feet agl
becoming mainly VFR ceilings 3500-5000 feet by 20z. Increasing
showers and tstms mainly across southeast Ohio and northern WV
this afternoon...vicinity of the nearly stationary weak front. SCT
showers and tstms central and south.
After 02Z...most convection decreases with loss of heating. Generally
SCT-BKN 4000-8000 feet AGL with widely SCT showers mainly in the
north. 08z-12z MVFR river valley fog...except lower in the north
if earlier rains fall.
After 13z Wednesday...4000-6000 feet AGL with widely SCT showers
and tstms developing by 18z.
Winds this period nearly calm by night...light and variable by
CONFIDENCE AND ALTERNATE SCENARIOS...
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: Medium.
ALTERNATE SCENARIOS: A shower or thunderstorm could directly affect
any TAF site Tuesday afternoon. Timing of Fog formation and
intensity may vary tonight depending on where it rains.
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 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H 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 H H H 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 WEDNESDAY...
Brief IFR conditions possible in thunderstorms every afternoon
and evening. Early morning IFR fog possible into mid week
depending, in part, on occurrence of showers or thunderstorms the
previous afternoon or night.
WV...Flash Flood Watch until 10 PM EDT this evening for WVZ007>011-
OH...Flash Flood Watch until 10 PM EDT this evening for OHZ075-076-
KY...Flash Flood Watch until 10 PM EDT this evening for KYZ101.