Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston WV
110 PM EST Thursday Mar 5 2015
Arctic high pressure cuts off snow late today. High pressure gives
dry weather for the weekend with a warming trend.
Near term /through tonight/...
1 PM update. As heavy snows pull away this afternoon...have expired
the Winter Storm Warning west of the Ohio River at 1 PM.
10 am update...current forecast looks good. Heavy snow will be
tapering off from northwest to southeast this afternoon. Winter
Storm Warning will begin to expire in the far northwest at 18z.
Short term /Friday through Sunday/...
some weak disturbances move north of the region for Friday through
Sunday...but insufficient moisture prevents any precipitation. Will
keep temperatures on the lower side of guidance due to snow on the
Long term /Sunday night through Wednesday/...
west-northwest flow aloft with a general tendency for slowly rising heights on
the anticyclonic side of the jet spells basically a temperature/dew/sky
forecast. A weak cold front and corresponding upper level short wave trough
cross sun into sun nt...with the small chance for snow showers north. A
polar Pacific high follows for the early portion of the new work
week. A warm wave approaches from the S day 7...as the confluence
zone lifts north of the area...allowing the upper flow to turn SW ahead
of a southern stream short wave trough.
Lows Sat nt were close to guidance...but did a warm ridge/Cold
Valley separation. Otherwise blended in wpc for little change on
lows Monday and Tuesday nights. Blended in wpc and European model (ecmwf) for highs through
the period...a little lower sun and a little higher on Tuesday compared
with previous. Overall have a steady temperature trend early on
with a slow melt given lows and dew points below freezing and highs
in the 40s. Temperatures and dew points trend upward during the
latter portion of the period per aforementioned height rises and S
to southeast flow on back side of exiting high pressure...and ahead of warm
wave approaching from the S.
Aviation /18z Thursday through Tuesday/...
18z Thursday through 18z Friday...
at 18z mostly VFR ceilings west of the Ohio River. Widespread
IFR/LIFR conditions in snow...mainly along and east of the Ohio
River at 18z...will continue improving from west to east this
afternoon...to MVFR ceilings as the snow ends.
For this afternoon. Expect VFR conditions west of the Ohio
River...MVFR ceilings by 21z reaching a crw-ckb line and into the
mountains by 00z. Clearing then spreads southeastward...becoming
mostly clear by 00z west of the Ohio River...by 06z reaching a
crw-ckb line...and into the mountains by 09z.
Snows will mainly be confined to the mountains by 22z..and end there
by 05z. After 09z...mainly VFR with scattered stratocu after 14z.
Northwest winds on the order of 5 to 10 kts with a few gusts to 20 kts
ridgetops...will become light by 06z.
Forecast confidence and alternate scenarios through 18z Friday...
Forecast confidence: medium.
Alternate scenarios: snow may end faster this afternoon...an
clearing may be faster tonight.
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
EST 1hrly 13 14 15 16 17 18 19 20 21 22 23 00
crw consistency h h h M h h h h h h h h
heights consistency h h M h h h h h h h h M
bkw consistency h h h h h h h h h h h M
ekn consistency M h h h M M h h h h h h
pkb consistency M M M h h h h h h h h h
ckb consistency h h h M h h h h h h M M
After 18z Friday...
no widespread IFR conditions are expected at this time.
WV...Winter Storm Warning until 7 PM EST this evening for
Kentucky...Winter Storm Warning until 7 PM EST this evening for kyz105.
Virginia...Winter Storm Warning until 7 PM EST this evening for vaz003-