Area Forecast Discussion
Issued by NWS Charleston, WV-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KRLX 261738
Area Forecast Discussion
National Weather Service Charleston WV
138 PM EDT THU MAY 26 2016
Weak disturbances aloft in an upper level ridging pattern. Slow moving
convection with heavy downpours Friday/Saturday. Southeast flow
may increase shower coverage late Sunday or Monday especially over
.NEAR TERM /THROUGH FRIDAY/...
-- Changed Discussion --Area of showers associated with upper disturbance across eastern
Kentucky...southern WV and southwest VA...will continue to slowly
track eastward-southeastward through the day. To the west...line
of convection associated with another upper disturbance across
central Indiana/southern IL/western KY is progged to continue
eastward...and may affect ne KY and southeast Ohio counties
late...although by the time it arrives...should be weakening with
the loss of any heating...and an overall lack of instability
across the area. Increased pops for a couple of hours this
evening across northeast KY and adjacent southeast Ohio and WV
counties. Otherwise...expect an overall lull in the activity late
Another warm and muggy night is on tap again...with dew points in
the 60s. May see a little more fog formation tonight than last
night...particularly in any areas that receive rain.
Friday looks to be another hot and muggy day as upper ridge
rebuilds across the eastern U.S. No significant waves are expected
to move into the area...and thinking that best chance for showers
and thunderstorms will be across the mountains due to differential
heating. Did add in slight chance to chance across parts of the
lowlands Friday afternoon and evening in case anything moves off
the mountains in the southeasterly flow. One thing to note...is
the overall flow is very light...less than 5kts through the
profile...and expect little movement with the storms. Thus...with
the high moisture content of the air...storms will be heavy
dumpers...and could cause quick rises on area streams and creeks
and water issues in low lying spots. This is something that will
need to be monitored.
-- End Changed Discussion --
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
Very weak flow on Friday...tries to increase just slightly on
Saturday...with no fronts in sight.
As a result...no significant mid level disturbances to latch onto.
Will try to have the higher pops Friday over the central mountains
counties...and forming first...with the differential heating. As
mentioned yesterday... can still picture convection over the
southern mountains late afternoon trying to drift north into
southern coal fields and toward Hts or Crw. So left chance pops
over the southern lowlands well into the warm Friday evening.
Localized/isolated downpours can occur under this slow moving
convection on Friday afternoon and evening with precipitable water
around 1.5 inches.
Forecast model soundings showing more instability Saturday
afternoon...while drier air aloft tries to move northwest into
the mountain counties during Saturday afternoon and evening. So
chance pops just as high in the western lowlands Saturday...when
compared to mountains. Again...isolated downpours Saturday
afternoon and evening...probably western lowlands.
On Sunday we are still looking south and southeast. Disturbance
along Carolina coast may increase moisture late Sunday into Monday
and hold down temperatures...especially along eastern slopes.
Temperature wise...forecast a few more 90 degree reading Friday
afternoon if convection holds off until evening for the southern
river valleys like Logan Louisa...Charleston...and Huntington.
At this distance...with weak downslope winds west of the mountains...
we did not lower maximum temperature forecast on Sunday in the western
lowlands as much as...say the 00z Gfs mex guidance suggests.
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
Summer like weather will continue during the period as an upper
level ridge remains over the area. Warm afternoons and cool nights
will be the rule. There could be some convection Saturday night
due to afternoon heating and juicy airmass.
The upper level ridge hold until Sunday before drifting off the
east coast. Continue with low chance for the remainder of the
period especially during the afternoons.
A developing tropical system approaches South Carolina by Tuesday
morning. It is a little early to have high confidence on the track
of this system. Will monitor the development and track of this
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --Isold showers and thunderstorms developing this
afternoon...lasting through around 23Z. Expect brief heavy
downpours and brief MVFR conditions in vicinity of storms. Outside
of storms...VFR conditions with light surface winds.
Overnight...patchy MVFR and IFR valley fog developing generally
after 07Z...with VFR conditions returning with light surface winds
after 13Z. Isold convection possible again towards end of TAF
period across mountains.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY...
FORECAST CONFIDENCE: Medium to high.
ALTERNATE SCENARIOS: More convection may develop this afternoon
than currently forecast. Fog may not form overnight...particularly
if little clearing of cloud deck occurs.
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 FRIDAY...
No widespread IFR conditions expected.
-- End Changed Discussion --
The river gauge...and forecast point...at the South Side Bridge
in downtown Charleston has not be reading correctly. The NWS
hydrologist is working to correct this problem.