Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston WV
310 PM EST Monday Nov 30 2015
stationary front returns as a warm front later tonight. Cold front
crosses Tuesday night into early Wednesday. Colder air Wednesday
night. High pressure builds late Wednesday through weekend.
Near term /through Tuesday/...
a stationary frontal boundary south of the area will gradually
lift north as a warm front through tonight. Models are in
agreement with the timing of precipitation...bringing the bulk of precipitation
overnight into Tuesday ahead of an approaching cold front.
However...it is evident a lull in precipitation this afternoon and evening.
Adjusted probability of precipitation to represent these thoughts...having categorical
probability of precipitation spreading from south to north later tonight. Categorical probability of precipitation
will move east on Tuesday as the cold front approaches from the
west with drier air behind it.
Temperatures at the surface and aloft will be warm enough for precipitation to
stay liquid through the period. Used the all blend and super blend
guidance for temperatures through the period.
Short term /Tuesday night through Thursday/...
130 to 150 knot elongated NE to SW jet maximum at 250 mb Tuesday night
into Wednesday evening over the front. Hard to determine any one
specific area with enhanced lift due to the associated jet dynamics.
Still concerned about the intensity of the rain over eastern and
southeastern counties Tuesday night...as the front slowly down
overnight Tuesday night in its push east.
We will be monitoring how much rain falls this Monday night into
Tuesday... to determine if any Flood Watch needs posted for the
latter portion of this prolong episode...with the various
rounds of rain.
Drier punch comes in behind the front in southeast Ohio and NE Kentucky
overnight Tuesday night...so reduced sky coverage before the colder
air moistens up the low levels Wednesday afternoon and evening.
Will base forecast on the coldest 850 mb temperature of minus 6 to minus 8c
for 12z Thursday. Thinking depth of low level moisture is
sufficient enough to increase clouds and probability of precipitation in the thermal
temperature trough 06z Thursday to 15z Thursday. Will include
about an inch of snow at or above 4000 feet...so not much in the way of snow.
Have the stratocumulus with the colder air drying up SW to NE
Long term /Thursday night through Monday/...
surface high pressure will dominate the long term. This will provide
dry weather...mild days and cool nights. Next system should hold off
until after the end of the period...but cirrus may be on the
increase Sunday into Monday.
Aviation /20z Monday through Saturday/...
IFR ceilings at bkw and heights will improve to VFR later this
afternoon. VFR/MVFR ceilings expected over the rest of the area
through tonight. Plenty of middle to upper level clouds will prevail
through the period.
A middle level vorticity maximum crosses the area from the southwest tonight.
Consequently...a warm front will lift north tonight...to increase
the probability for rain and associated IFR/LIFR conditions
overnight. Conditions will improve late Tuesday afternoon as the
middle level wave moves through. However...a cold front is expected
to cross the area Tuesday night.
Forecast confidence and alternate scenarios through 18z Tuesday...
Forecast confidence: medium.
Alternate scenarios: timing of any category changes may vary.
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 M M M M M M M M M l l l
heights consistency M M M M M l l l l l l l
bkw consistency M M M M M M M M l l l l
ekn consistency h h h M M M l M M M M M
pkb consistency M M M M M l l l l l l l
ckb consistency M M M M M l l M M h M M
After 18z Tuesday...
IFR possible in clouds and rain into Tuesday night as warm front
then cold front pass.