Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston WV
211 PM EDT Wednesday Oct 7 2015
high pressure expected through Thursday. A cold front brings
showers and thunderstorms Friday. High pressure for the weekend.
Near term /through Thursday/...
one last day of dry and warm weather Thursday before a cold front
arrives Friday. High pressure centered over the Mississippi
Valley this afternoon will shift east across the area
tonight...and be centered along the middle Atlantic coast by Thursday
evening. Much of the afternoon stratocu in the north and east
this afternoon will dissipate with loss of heating early this
evening. Before the high center shifts east of US later
tonight...models indicate enough low level moisture in the east on
light northerly flow at 925mb for some redevelopment of
stratocu...mainly along and on west slopes of the mountains.
There is a question of whether significant clouds will actually
form to inhibit valley fog in the northern mountains...and if they
do...the extent of the clouds out into The Lowlands. Will handle
things similar to this morning...where we downplay clouds enough
to form River Valley fog as last night...the fog affecting
crw...ekn and heights.
For Thursday...look for sunshine after early morning fog and
clouds...with southerly breezes kicking in...allowing
temperatures to reach 80 degrees in many locations Thursday
Short term /Thursday night through Friday night/...
high pressure and dry weather remain in place Thursday and
Thursday night. Models are in agreement with a delay on the onset
of an approaching cold front and associated precipitation. The
NAM...GFS...and European model (ecmwf) show their quantitative precipitation forecast fields reaching portions of
southeast Ohio by 12z Friday. Therefore...delayed the onset of precipitation
with the bulk moving from east to west through Friday evening.
The NAM show surface based cape reaching 1600 j/kg ahead of the front
with descent boundary layer convergence. Therefore...expect
thunderstorms to ride along and ahead the cold front mainly Friday
Expect above normal temperatures Thursday afternoon...generally in
the middle to upper 70s lowlands ranging into the middle 50s highest
elevations. By Friday...abundant clouds and widespread showers
with few thunderstorms will keep afternoon temperatures around 70
degrees lowlands ranging into the middle 50s highest elevations.
Cooler air filters in behind the cold front bringing high
temperatures in the lower to middle 60s Saturday. Went closer to the
super blend guidance for temperatures through the period.
Long term /Saturday through Tuesday/...
still a question on how fast the deeper moisture exits Friday night.
A sharpening 500 mb trough is aided by the divergence from the right rear
of an 200-300 mb jet maximum. This may slow system down Friday evening.
Will linger likely probability of precipitation longer Friday night in WV and SW Virginia and chance
probability of precipitation in the mountain counties Saturday morning.
In its wake...finally get into a fast west-northwest steering flow Monday and
Tuesday with weak middle level disturbances...with low level warm air
advection through 850 mbs. This makes temperature and pop forecast difficult.
Hard to time...but did include some slight chance probability of precipitation Monday night
Still no killing frost foreseen.
Aviation /18z Wednesday through Monday/...
18z Wednesday through 18z Thursday...
high pressure center moves east across the area tonight.
VFR ceilings mainly along and east of a ckb-crw-bkw line....
except MVFR ceilings higher elevations of the northern mountains of WV.
Elsewhere scattered VFR stratocu. Mainly light north to northwest flow this
After 21z...decreasing clouds.
After 03z...generally scattered middle clouds...except becoming broken
6000-8000 feet above ground level at times in mainly the northern moutnains.
This means LIFR fog possible again after 07z in crw...heights ..and
even at ekn where enough breaks in the clouds are expected. So
similar conditions tonight compared to last night with near calm
After 13z Thursday....generally VFR scattered clouds with light
southerly breezes kicking in.
Forecast confidence and alternate scenarios through 18z Thursday...
Alternate scenarios: the extent of River Valley fog may vary early
Thursday morning...depending on formation and extent of nocturnal
Experimental table of flight category objectively shows consistency
of weather forecast office 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
heights 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...
IFR conditions could occur in and around thunderstorms on Friday.