Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston WV
523 am EST Sat Dec 27 2014
high pressure maintains control today. A cold front crosses late
tonight into Sunday. A wave of low pressure moves along the front
Sunday. Drier...colder air slowly builds in to close out 2014.
Near term /through tonight/...
radar images indicate light precipitation in the form of sprinkles moving
northeast across the area early this morning. This precipitation is falling
from an upper deck of clouds most of it not reaching the ground.
High pressure remains in partial control today...with warm air
advection under southerly flow at the surface and southwest at h850.
Therefore...expect above normal temperatures through tonight.
Plenty of upper level clouds will gradually thicken ahead of the
upcoming cold front. Cold front passes overnight tonight
increasing probability of precipitation to likely to categorical per model consensus.
Winds will shift from southwest to west northwest behind the cold
front by 09-12z Sunday.
Went closer to all consensus blend for temperatures through the
Short term /Sunday through Tuesday/...
overall...models locked into the short term pattern pretty well
which equates to minimal changes across the short term. Biggest
changes are bumping up the probability of precipitation with added confidence to the
forecast this morning. Otherwise...the story is the same with a cold
front pushing in...going stationary with a wave forming along
it...and ultimately having difficulty exiting the area with the middle
and upper level steering flows nearly parallel to the surface
boundary. As noted last night...no upper level trough axis keeps
this system on the weaker side with quantitative precipitation forecast totals less than half an
inch for the most part. Still have some questions about possible
snow totals in the highest ridges of the mountains Sunday night and
Temperatures fall behind the front eventually to more normal
December values...but still not tapping into any really cold Arctic
air just yet. Few changes to the temperatures in the short term as
well with the most noticeable changes being to the southeast Ohio
counties on Sunday night and taking them below freezing.
Long term /Tuesday night through Friday/...
overall a fairly quiet long term period. Have probability of precipitation tapering off
Monday night as moisture departs. Bring back in some slight chance
probability of precipitation in the mountains for late Tuesday and Tuesday night with 850mb
temperature trough and weak 500mb shortwave trough sliding through.
High pressure noses in for Wednesday and Thursday. Both GFS and
European model (ecmwf) showing a system moving out of the lower Mississippi Valley at
the end of the week...so do start increasing probability of precipitation right at the end
of the period. Blended new wpc guidance into previous forecast for
temperatures...and then went just a touch cooler on lows.
Aviation /10z Saturday through Wednesday/...
high pressure remains in control with VFR conditions prevailing
through at least 00z Sunday. High level clouds will gradually
thicken as a cold front approaches from the west. Winds will
continue light from the south today.
The cold front and associated precipitation will move into
southeast Ohio towards 09z Sunday...with isolated MVFR conditions
with associated rain showers.
An upper level disturbance will ride along the front continuing to
produce rain showers across the area into Sunday. MVFR ceilings
will be possible along these showers. Coded MVFR conditions by 09z
Sunday becoming IFR by the end of the period.
Forecast confidence and alternate scenarios through 12z Sunday...
Forecast confidence: high.
Alternate scenarios: MVFR conditions could become IFR with the
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.
Date Sat 12/27/14
UTC 1hrly 08 09 10 11 12 13 14 15 16 17 18 19
EST 1hrly 03 04 05 06 07 08 09 10 11 12 13 14
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 12z Sunday...
IFR possible in rain Sunday into Monday.