Area Forecast Discussion
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FXUS61 KRLX 261041
Area Forecast Discussion
National Weather Service Charleston WV
641 AM EDT MON SEP 26 2016
A cold front crosses late today with showers and thunderstorms. A
large upper level low drops into the area Wednesday and Wednesday
night, and then swirls about the area Thursday through Friday.
.NEAR TERM /THROUGH TONIGHT/...
As of 515 AM Monday...
Models agree on a cold frontal passage this afternoon and evening.
A north to south temperature and dew point gradient has set
up across the area on account of a cold front that slipped into
the area from the north on Saturday. While the gradient will
shift northward today in the strengthening southwest flow ahead of
the approaching cold front, it looks like the greatest
instability and potential for the strongest thunderstorms will be
across southern portions of WV, and back into eastern Kentucky.
Mid level flow increases to 30 to 40 kts and CAPE approaches 2 KJ /
KG in a narrow axis just ahead of the cold front. The stronger of
the multi-cells could produce minor damage. The HWO mentioned is
maintained per SWODY1.
Tonight will bring clearing in the wake of the front, with a brief
period of post-rain fog and stratus.
Highs and lows were close to the latest guidance, so not much
change was needed. Hourly temperatures reflect the north to south
baroclinic zone this morning, and then a more west to east
gradient associated with the cold front later today.
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
As of 515 AM Monday...
Cooler and unsettled weather in the short term period. Upper
low/trough will dig south across the region...rotating across the
area for much of the week. This will usher in much cooler...and
showery weather to the CWA. Elected to lower temperatures slightly
during the period...particularly on Thursday...with upper low over
region...and 850mb temps dipping into the single digits. With that
being said...it`s possible max temperatures on Thursday may be even
slightly cooler than currently forecast.
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
As of 315 PM Sunday...
Operational GFS, in a bit of a surprise, has now trended towards
the operational ECMWF with the closed low aloft oscillating around
over the eastern CONUS. Ensemble members still lean towards an
quicker exiting open wave aloft...but the GFS ensemble mean
changes from 00Z to 12Z look to be coming more in line with the
aforementioned operational long term models. From a sensible
weather standpoint, this typically results in a more off than on
precipitation scheme and a temperature forecast that can end up
cooler than the guidance numbers suggest. For the time of year,
nothing seems out of the ordinary in the forecast based on
seasonal norms, however.
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
As of 640 AM Monday...
BKW is on the edge of a stratus deck just to the east early this
morning. While IFR ceilings are not likely to materialize there,
MVFR morning cu is still possible there this morning. Elsewhere,
valley fog did not amount to much this morning, and any fog that
is out there will quickly burn off.
A cold front approaching from the west today will bring a line or
two of showers and thunderstorms this afternoon into early this
evening. Timing is 18-23Z along the Ohio River, 20-00Z CKB to
CRW, and 21-02Z in the mountains. The front will cross near the
end of the above mentioned time ranges.
A brief period of stratus and fog is likely to follow the cold
front tonight, although this may tend to linger in and near the WV
Light south surface flow early this morning will become gusty
southwest ahead of the cold front today, with stronger gusts
possible in thunderstorms. The wind will shift to west to
northwest behind the front, and be briefly gusty before
diminishing and backing to southwest overnight tonight. Light
southwest flow aloft early this morning will become moderate
southwest ahead of the front this afternoon, and then light to
moderate west to northwest behind the front tonight.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: Medium.
ALTERNATE SCENARIOS: MVFR stratocu may not form at BKW this
morning. The timing and impact of showers and thunderstorms with
the front this afternoon and early evening may vary. Stratus and
fog behind the front tonight may vary.
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 10 11 12 13 14 15 16 17 18 19 20 21
EDT 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY M M M M H H H H H H H L
HTS CONSISTENCY H H H H H H H H H H H L
BKW CONSISTENCY L L L M M H H H H H H L
EKN CONSISTENCY M M M M H H H H H H H L
PKB CONSISTENCY H H H H H H H H H M M L
CKB CONSISTENCY M M M H H H H H H H H L
AFTER 12Z TUESDAY...
Morning valley fog possible Tuesday through Friday mornings.