Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston WV
422 am EST sun Feb 1 2015
precipitation at times...as low pressure system passes over the
forecast area today. Much colder air blows in on Monday. High
pressure builds in Monday night into Tuesday.
Near term /through tonight/...
precipitation beginning to spread over the area...with virga
transitioning to measurable precipitation at the surface over the next
few hours. A tricky area of freezing rain may develop along edge of
precipitation shield this morning so issued Special Weather Statement to highlight this. The
area is fairly transient and small in scale as temperatures
quickly warm behind the precipitation band. Due to this small scale and
elusive nature...opted not to issue an Freezing Rain Advisory.
For the rest of the day...temperatures warm from the southern Coal
fields north. So in the northern tier of our forecast area it will
be snowing while the southern half temperatures will be in the 50s.
Winds and precipitation will increase tonight as the low pressure system
gets closer. Precipitation type will begin to change back to snow
over southeast Ohio towards Monday morning.
Short term /Monday through Tuesday night/...
strong low pressure system exits northeast Monday.
However...models indicate very cold air behind its associated cold
front changing any precipitation to all snow. The flow will shift from the
northwest to produce ideal set up for upslope snow over the
northeast mountains while moisture remains available through
Monday night. The rest of The Lowlands and central mountains will
see snow after dawn on Monday.
As the moisture starts to decrease after all precipitation transitions into
snow...only light accumulations are expected...generally 2 to 4
inches possible across Perry County....with 1 to 3 in Morgan
County...and around an inch for the remainder of southeast Ohio.
Expect much of the West Virginia lowlands to receive around an
inch or less...except northern West Virginia lowland counties such
as Clarksburg area...where a good inch or two will be possible.
Northeast mountains could easily get 2 to 4 inches...with higher
amounts possible on northwest facing slopes. The snow will transition
to a lighter fluffier snow as the day progresses on Monday as
850mb -16c air rushes into the region.
A Winter Weather Advisory remains for Perry and Morgan counties
through Monday morning. Will keep monitoring the potential for
additional advisories over mountainous counties.
High pressure will build in late Monday night into Tuesday...with
dry conditions...and moderating temperatures.
Long term /Wednesday through Saturday/...
broad eastern middle/upper level trough with fast flow...and few
opportunities to access the Gulf of Mexico moisture.
Weak warm air advection ongoing Tuesday night...will try to bring
some 20/30 probability of precipitation a bit faster south by dawn Wednesday into our
12z GFS a bit more aggressive with the moisture moving up the Ohio
Valley Wednesday along that frontal boundary. European model (ecmwf) certainly not as
moist. For now...will keep probability of precipitation in chance category with front
Wednesday into Wednesday night.
Have colder air blowing south again overnight Wednesday night into
Thursday. Went colder than our previous forecast.
Drying again Thursday night through Friday night.
In the fast flow...next system could arrive by late day 7.
Aviation /09z Sunday through Thursday/...
VFR for now...a transition to MVFR will occur late in the taf
period. The exception being the northern taf sites that will be
closer to the warm front this morning will turn to MVFR earlier.
These sites will also be in the cooler frozen precipitation area.
Forecast confidence and alternate scenarios through 06z Monday...
Forecast confidence: high early on...descending to medium.
Alternate scenario: timing of drops in flight conditions and degree
and duration of worst conditions may vary. Timing of precipitation type
transitions may also vary and...while not explicitly coded up...freezing rain
is a possibility pkb...ckb...ekn...and even a slight chance freezing
rain early Sun morning heights and crw.
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 sun 02/01/15
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 M 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 M M M M M M M M h
pkb consistency h h h h h M M M M M M M
ckb consistency h h h h h M M M M M M M
After 06z Monday...
IFR conditions possible in snow late overnight Sunday night over the
middle Ohio Valley...and the higher WV mountainous
terrain....lingering in and near the WV mountains into Monday.
Ohio...Winter Weather Advisory until 10 am EST Monday for ohz066-067.