Area Forecast Discussion
Issued by NWS Charleston, WV-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KRLX 291624
Area Forecast Discussion
National Weather Service Charleston WV
1224 PM EDT THU SEP 29 2016
-- Changed Discussion --A large upper level low will bring unsettled wet weather through
Friday. It pulls away in time to bring dry weather for much of the
weekend. High pressure continues the dry weather early next week.
-- End Changed Discussion --
.NEAR TERM /THROUGH FRIDAY/...
1050 am update...Added a higher chance of thunderstorms to the
forecast through today. With cold temps aloft and low freezing
levels any storms that reach about 15K feet should start producing
lightning. Also, I did not put any hail in the forecast at this
time, but some isolated stronger storms could produce small hail.
850 am update...Went ahead and boosted PoP across the CWA today
with the upper low producing widespread showers. Current thinking
is that Flash Flood threat is fairly low today...however we will
have to monitor for training today with unidirectional flow and
diffluence aloft . It is still possible that a flash flood watch
may be needed at some point...but will hold off at this time due
to dry conditions and uncertainty on where the heaviest
precipitation will set up.
As of 420 AM Thursday...
Unsettled and cool weather for the near term period...as surface
cold/occluded front pushes east through the region today...and as
upper low...which will slowly dig south into Kentucky today...and
associated vort maxes...help to trigger showers and
thunderstorms...particularly this afternoon. There is the
possibility that a few storms could be on the strong
side...particularly across the eastern 2/3 of the CWA. Any breaks
that are able to develop in the cloud cover today will help to
destabilize the environment...and this combined with strong
shear...could lead to organized/strong convection...with damaging
winds a primary threat. Small hail can also not be ruled
completely out...or the possibility of an isolated tornado. SPC
has placed the majority of the CWA in a marginal risk...with
southern/eastern WV zones in a 2 percent for tornadoes. Will
highlight in the HWO. In addition to the severe threat...there
will be heavy downpours with any storms...but with the overall dry
conditions and storm movement...not concerned about issuing any
water headlines. Based on water vapor imagery...and model
consensus...heavier axis of moisture/precip should stay just to
the east of the CWA...where stronger low level winds will aid in
higher moisture transport off the Atlantic.
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
-- Changed Discussion --As of 1222 PM Thursday...
Large upper level low over the lower Ohio Valley will move to
northern Indiana by Saturday afternoon and then to the eastern
Great Lakes late.
Showers will be most numerous across northeast portions of the
area early Friday night. However, coverage should quickly
decrease by early Saturday with much of the area getting into the
There could still be a few showers in the northern mountains as
well as portions of northeast Ohio early Saturday night. However,
expect Sunday should be dry across the area.
Used a blend of guidance for lows and highs.
-- End Changed Discussion --
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 1205 PM Thursday...
Period will begin with pesky upper low moving away from the
region. Upper level ridge will build in as an upper level trof
approaches from the west. Models differ on the track of Tropical
Storm Matthew. GFS has the system moving along the North Carolina
coast while the ECMWF has it well to the south. Current thinking
is to follow WPC timing which is close to that of the GFS.
End result should be dry weather Sunday night through Tuesday
before the flow around Matthew begins to push some moisture
westward into the mountains. This increasing moisture could
result in some afternoon/evening showers and storms in the
northern mountains Wednesday and Thursday.
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
As of 630 AM Thursday...
Upper level low will continue to rotate across the area during the
period...with areas of showers...and thunderstorms...particularly
after 16-18Z. Expect brief gusty winds...heavy downpours...and
MVFR/IFR conditions at times...particularly in vicinity of
showers/storms. Bulk of convection will die off after
00Z...however...showers with restrictions...and areas of MVFR/IFR
cigs and vsbys will continue to linger for the remainder of the
period. Isold LIFR possible in low cigs and fog after 06Z.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY...
FORECAST CONFIDENCE: Medium.
ALTERNATE SCENARIOS: Coverage and timing of convection this
afternoon...and resultant MVFR/IFR restrictions may vary from
forecast. Isold LIFR in question 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 15 16 17 18 19 20 21 22 23 00 01 02
EDT 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
CRW CONSISTENCY H H H H L H H H M L L L
HTS CONSISTENCY M M H H M L L L M L L L
BKW CONSISTENCY M M M H H H H H H L L L
EKN CONSISTENCY H H H H H H H H H H H L
PKB CONSISTENCY M M M M M H M M M L L L
CKB CONSISTENCY H H H H H H H H H H L L
AFTER 18Z FRIDAY...
Areas of ifr possible in showers and thunderstorms through
Saturday, and in dense fog Sunday and Monday mornings.