Area Forecast Discussion
Issued by NWS Charleston, WV
FXUS61 KRLX 251859
Area Forecast Discussion
National Weather Service Charleston WV
259 PM EDT WED MAY 25 2016
Weak disturbances within ridge aloft today through Thursday.
Southeast flow may eventually increase shower coverage Sunday
into Monday...especially over mountains.
.NEAR TERM /THROUGH THURSDAY/...
Unsettled weather returns for the near-term period...high pressure
at the surface with upper ridge across eastern US...with above
normal temperatures...and increasing relative humidity. Several
weak upper disturbances will affect the region during
period...one this afternoon/evening...increasing chances of
showers and storms mainly across far western zones. Thunderstorms
will be isolated at best owing to weak instability and cloud cover
inhibiting convection. Initial wave will weaken as it crosses area
but additional waves expected tonight and tomorrow...which will
trigger additional rounds of showers and isolated thunderstorms.
With lack of strong dynamics no severe storms expected.
Tonight will be warmer as dew points and cloud cover increases
with upper-level disturbance. Continued above average
temperatures with rebounding heights for tomorrow.
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
Sfc high pressure will extend from the OH Valley east across the
Appalachians into the mid Atlantic coast. Upper level ridge is also
evident in models suggesting mainly fair weather in the short term.
There is no major system affecting the area during this period.
However, can expect afternoon convection produced by a combination
of diurnal heating, differential heating and occasional vorticity
max through at least Saturday. The NAM models show sfc based CAPE
exceeding 2000 J/Kg during the afternoon hours on Friday and
Saturday with precipitable water around 1.7 inches.The flow becomes
southeast Saturday pushing a boundary, evident in GFS H700 Theta-e
packed gradient field,north under south southeast flow. This will be
a high CAPE, low deep layer shear environment. Coded thunder for
CAPE equal and greater than 2000 J/Kg. Some storms can produce heavy
downpours conducive to localized water problems.
Went mainly with the super blend guidance for temperatures through
.LONG TERM /SATURDAY 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 /19Z WEDNESDAY THROUGH MONDAY/...
Mainly VFR conditions through period with light surface winds.
Scattered showers and isolated thunderstorms developing after 20Z
creating low VFR or isolated MVFR conditions. Bulk of convection
decrease after 02Z with loss of heating but will redevelop
Thursday after 16Z.
Patchy low VFR fog possible sheltered mountain valleys such as at
KEKN late tonight.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z THURSDAY...
FORECAST CONFIDENCE: High.
ALTERNATE SCENARIOS: Brief MVFR in a shower is possible.
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 THURSDAY...
No widespread IFR conditions expected.