Area forecast discussion
National Weather Service Charleston WV
249 PM EDT Sat may 25 2013
Synopsis...
high pressure in charge today. Warm front lift northeast through
area late Monday into early Tuesday. In its wake...increasing heat
and humidity Tuesday into Thursday.
&&
Near term /through Sunday/...
1100 am update...
much of mountains dipped below freeze early this morning along with some of
the adjacent north lowland Colorado. Pesky stratus kept mountain valleys from realizing
full potential. Coldest saw was on the highest ridges...ie
Snowshoe with 24f. Elsewhere...generally 32 to 36f observed across
much of southeast Ohio and north WV lowlands. 35 to 40f once to i64 and NE
Kentucky...with more dew than anything observed...with some frost seen
on the roofs and elevated sfcs. Even had some on the Maple leaves
at the office where 35f was observed. 2 records were set...pkb and
bkw with heights tying theirs.
As for today...should see flat stratocu across the north mountains today and
extreme north lowlands before dissipating later this afternoon. Impressive
upper low along New England coast will keep region in northwest flow surface
and aloft today. Will look upstream in west Ohio Valley for debris clouds
to spill in from decaying complex over upper MS valley. Have bumped
up sky grids across NE Kentucky/S WV/SW Virginia this afternoon for more in the way
of middle/hi clouds from this feature. Otherwise...inherited temperatures look
good to go. Will be figuring out frost potential next few hours
across north lowlands tonight.
Previous discussion below...
a chilly morning on going...with below freezing temperatures in
northern WV mountains...and temperatures cool enough for frost in
parts of the lower terrain. Will let the current frost/freeze
headlines ride out. Although not likely to get cold enough for any
impacts in metropolitan areas like Charleston and Huntington...its tough to
say how temperatures are doing in the outlying hollows where no
measurements are available.
With surface high pressure in control through tonight...expecting
dry conditions through the near term period. With a couple ripples
in the northwest flow aloft...will see some clouds this
afternoon...with thicker clouds tonight across the SW quarter of the
County Warning Area. Farther NE...should be a fairly clear night...allowing for
another frost across the northern mountainous counties.
Mav/met continue to have some differences in temperatures today and
tonight. Blended in the consall guidance for highs and lows...which
is between the mav/met although closer to the warmer met.
&&
Short term /Sunday night through Tuesday/...
still feel uncertain/low confidence in the areal coverage...and thus
the pop...for the warm front for Memorial Day into Tuesday. The 00z
NAM and GFS still not very aggressive with showers. The European model (ecmwf) was
trending in that direction. At least our timing has not changed
much in the past 24 hours.
The Saturday night disturbance aloft should be exiting on Sunday
morning...keeping northern counties almost cloudless on Sunday.
High and middle clouds may start increasing again across the south late
in the day. For the 3rd night...did mention some frost overnight
Sunday night/dawn Monday for Randolph and Pocahontas counties.
Generally stayed higher than 00z MOS probability of precipitation from both the NAM and GFS
for Monday into Tuesday...but still mostly 30 and 40 percent with
the warm frontal action.
Thinking the front itself would still be in our County Warning Area at dawn
Tuesday...before lifting north Tuesday afternoon/evening. Still not
be best low level inflow for US...better to our west in the
Midwest. But do remnants of those complexes...still survive...as
they move east-southeast along the warm front.
Warm front passage will open the door to Summer conditions for
midweek. The current fresh air will be just a memory.
&&
Long term /Tuesday night through Saturday/...
shortwave moving through the Great Lakes Tuesday night and associated
surface low pushing north into Canada extends a weak boundary from
southeast Ohio through central WV Tuesday night into Wednesday am...held probability of precipitation
overnight Tuesday into Wednesday afternoon with boundary exiting to the
north and SW flow from high pressure building over west Atlantic
enhancing upslope over eastrn mountains...with moisture advection from SW flow
around the periphery of the high across mountain on Thursday...increased
probability of precipitation slightly from Thursday after into Thursday evening...more of the same
for Friday after and evening over the eastern counties...models in general
agreement of strength and coverage of front approaching next
weekend...with the GFS more progressive than the Euro by the end of
the period by about 12-18hrs...went with a mix of the two overnight
Sat into sun.
&&
Aviation /19z Saturday through Thursday/...
some MVFR/IFR visibility/ceilings early this morning should
quickly dissipate and return to VFR by 13z-14z. VFR cumulus field will
develop today...generally 6-9kft. Upper level disturbance brings
clouds to the south tonight...but again remaining VFR.
Forecast confidence and alternate scenarios through 18z Sunday...
Forecast confidence...high.
Alternate scenarios: timing and density of fog dissipation 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
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 Sunday...
no widespread IFR expected.
&&
Rlx watches/warnings/advisories...
WV...frost advisory from 2 am to 8 am EDT Sunday for wvz011-019-020-
028>032-038>040-046-047.
Ohio...none.
Kentucky...none.
Virginia...none.
&&
$$
Synopsis...rpy/30/jm
near term...30
short term...ktb
long term...jm
aviation...30
