Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston WV
1033 am EST Wednesday Dec 11 2013
high pressure crosses and exits today. Arctic front crosses
tonight. Arctic high pressure builds Thursday and Friday. Low
pressure crosses this weekend with mixed precipitation.
Near term /through tonight/...
11 am update. New hi res models indicating more of a status deck as
the Arctic air comes in tonight. Have increased clouds early tonight
and included flurries across the north. Otherwise...no significant
much quieter in the near term this morning versus yesterday
morning...with only chilly temperatures and some upslope low stratus
over the eastern mountains. Did raise our overnight mins this
morning just a tad as locations such as crw still at 27f this
morning as of 08z. Aforementioned early morning stratus over the
mountains expected to scatter/burn off by mid-morning...leaving
behind mostly sunny skies for most locations. A vorticity maximum passing
to our north with a stalled front may result in a few more clouds
across the northern zones by this afternoon. Latest MOS guide
generally coming in around the 40f degree mark for The Heights-crw
corridor. Don/T really have a whole lot of snow cover across The
Lowlands...and with the slightly warmer head start this morning
and prognosticated 925mb temperatures about -2c...did raise maximum temperatures to near 40
degrees for the i64 corridor south into the coalfields. Southeast Ohio
zones will remain cooler...and also held temperatures down for eastern
parts of Raleigh County towards the eastern mountains where those
locations had a more substantial snowfall yesterday morning.
Early this evening a quick moving cold front brings a reinforcing
shot of colder air pushes across the area. Only expecting an
increase in cloud cover for most...perhaps some flurries across the
northern zones...and some light snow showers in favored upslope
areas of the northeast mountains primarily between 06z-12z Thursday
Post-front with the approach and passing of a short wave trough. Breezy
conditions for a few hours are expected as well Post-front...with
gusts for The Lowlands around the 20kt range. The high elevations
of Randolph through Webster counties will see stronger gusts up to
30-35kts. This along with temperatures dropping into the single digits
will result in wind chill values dropping to around -10f for
locations such as Snowshoe. Won't issue an advisory as these cold
wind chill reading will be primarily above 4000ft and thus won't
meet County-wide average...but did mention in the severe weather potential statement.
Short term /Thursday through Friday night/...
an Arctic high pressure will bring cold air under northwest flow
aloft. Models are in agreement with 850 mb temperatures around minus
14c early Thursday...increasing slightly to minus 9c by 03z
Friday. By 00z Saturday...a middle level shortwave will approach from
the southwest increasing mainly clouds due to limited moisture.
Perhaps few flurries are possible across the northern portions of
The Lowlands as the cold front passes through. Frontal passage expected
around 06z Saturday.
Northwest flow back from the west on Friday bringing some warm
advection an cutting off upslope effects over the mountains. So
kept flurries into Thursday morning there.
With cold air mass in place and some gusty winds...expect wind
chill into the single digits below zero over the highest terrain.
Tweaked the bias corrected MOS for lows through the period. Used
the all blend MOS family for highs.
Long term /Saturday through Tuesday/...
still under the influence of high pressure Friday...surface winds
develop an easterly component early Saturday in response to
deepening low pressure across the Tennessee Valley...deepest
moisture will be cutoff by the Appalachians remaining south and east
of rlx. Nonetheless we will see precipitation mostly in the form of rain
Saturday afternoon and evening with some mixed snow and rain in southeast
Ohio and the higher elevations of eastern mountain counties...as
the system moves northeast Saturday night into Sunday...any precipitation on
the backside of the low will be in the form of snow...not
expecting any significant accumulation at this point...high
pressure and cold air builds in behind the front with some diurnal
upslope snow showers Sunday...next system approaches our southeast Ohio
counties by Tuesday.
Aviation /16z Wednesday through Sunday/...
16z Wednesday through 12z Thursday...
a cold front will push southeastward late this afternoon and early
evening. Behind the front...expect a stratus deck to overspread much
of the the area from northwest to southeast after 20z...generally
becoming MVFR northern areas but VFR southern areas. Expect some
flurries across the north and some light snow showers in the
mountains. Some Post-frontal wind gusts are expected for a few hours
After 08z...clearing begins in the west while MVFR clouds hang through
12z east of the i79 corridor.
Forecast confidence and alternate scenarios through 18z Thursday...
Forecast confidence: high...medium between 06z Thursday and 12z Thursday.
Alternate scenarios: MVFR and IFR ceilings may be more widespread than
forecast primarily after 03z Thursday.
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 14 15 16 17 18 19 20 21 22 23 00 01
EST 1hrly 09 10 11 12 13 14 15 16 17 18 19 20
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 M M M 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 possible in snow...sleet...freezing rain and rain Saturday and
possibly lingering in snow showers Sunday.
kpkb ASOS remains ots...with additional parts on order. Augmented