Area Forecast Discussion
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FXUS61 KRLX 251804
Area Forecast Discussion
National Weather Service Charleston WV
204 PM EDT WED MAY 25 2016
Weak disturbances within ridge aloft today into Thursday. Ridge
stronger Friday/Saturday. 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/...
Certainly hard to grasp any significant feature and run with it.
Will have to wait until these time periods get into the near
term...and try to get more specific. So...as of now...hourly pops
certainly can not get out of the chance range.
Weak mid/upper level disturbances linger Thursday...before 500 mb
heights increase slightly Thursday night into Friday. Most of the
moisture plume in the lower Ohio Valley should remain to our west
Yet...the precipitable water still jump back to around 1.25 inches
Thursday and Friday. Then the southeast flow actually brings drier
air aloft on Saturday...lowering the precipitable water.
A weak flow dominates with afternoon and evening instability...so
reserved the mention of thunder for the afternoon and evening hours.
In the weak flow...tried to have the higher chance pops on Thursday
over the mountain counties. On Friday afternoon and evening...some
hints on both the 00z gfs and 00z nam that if some convective cells
form the southern mountains...it may try to drift north...off the
mountains into the southern lowlands.
Figuring a breeze stirs overnight Thursday night in southeast
Ohio...so have minimum temperatures a bit higher there. Otherwise...
in the light winds...have minimum temperatures a bit below guidance
in the hollers further south and east...but leftover clouds could
hurt that thinking.
We still have some 90 degree temperatures on Saturday...in the
southern river valleys...as that mentioned drying aloft occurs. Of
course...most official temperature sites in the lowlands have not
reached 90 degrees yet this year.
Due to a weak southeast flow...maximum temperatures along the
eastern slopes...including the southern plateau around
Beckley...are not forecast to be higher Saturday compared to Friday.
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
Summer like weather is still on tap for the Memorial Day weekend.
Upper level ridging holds into Sunday before drifting off the east
coast. Have just the slight chance for the late day shower or
thunderstorm Saturday, and then a better chance on Sunday as the
ridge begins to drift east.
As the ridge drift offshore, a weak upper level over the Carolinas
this weekend will start meandering to the northwest. This may
actually bring a developing tropical or subtropical feature
inland. Models generally differ with the track and lose the system
under the light upper level flow. Suffice it to say for now that
the forecast gets a bit dirtier early next week, with a better
chance for late day showers and thunderstorms and a non-
negligible chance at night.
Either way, the very warm and humid air remains in place through
the period, and even beyond. The midnight shift coded 90 for
Charleston for Saturday, which may be a touch aggressive, but the
pattern and guidance are close enough to give it a chance.
Overall, not much disparity between ongoing temperatures and
.AVIATION /18Z 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
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.