Area Forecast Discussion
Issued by NWS Charleston, WV-- Remove Highlighting --
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FXUS61 KRLX 261746
Area Forecast Discussion
National Weather Service Charleston WV
146 PM 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 1030 AM Monday...
Models in agreement with the convection associated with an
approaching cold front expected to spread showers and storm
tonight and Tuesday. High resolution models have the front
decaying as the cold front moves over our area. However, sfc CAPE
and deep layered shear can combine and produce tall thunderstorms
through this evening.
The line of showers have little lightning at this time.
Adjusted hourly PoPs and sky grids per latest model runs.
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 MONDAY/...
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 /18Z MONDAY THROUGH SATURDAY/...
-- Changed Discussion --As of 200 PM Monday...
Radar and satellite images indicate convection ahead and along an
approaching cold front. The PCPN activity will reach southeast OH
by 18Z, then will spread east. So, expect MVFR/VFR conditions
along showers or storms.
Thunderstorms are evident ahead of the front in wV. These storms
could produce a brief IFR condition under heavy rain.
The front slowly exit the area to the east by 02z tonight.
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
Moderate southwest flow ahead of the front, will become light to
moderate west to northwest behind the front tonight.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: Medium.
ALTERNATE SCENARIOS: 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 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 M H M H H M L H L
HTS CONSISTENCY H H H M M M H H H H H M
BKW CONSISTENCY H H H H M L L M L L H L
EKN CONSISTENCY H H H H H L M L L M H L
PKB CONSISTENCY H M M M M H H H H H H M
CKB CONSISTENCY H H H M L M M H M L L L
AFTER 18Z TUESDAY...
Morning valley fog possible Tuesday through Friday mornings.
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