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Area forecast discussion 
National Weather Service Charleston WV
631 am EST Wednesday Mar 4 2015

cold front tonight. Front stalls to the south with low pressure
moving along the front tonight into Thursday. High pressure Friday.


Near term /through tonight/...
cold front as of 06z has crossed crw and ekn and sagging southeast.
Narrow band of high reflectivities as well as WSR-88D velocity
image depicts front very nicely on its trek. Not looking at a
significant drop behind the front...but more of a slow decline.
Needless to say...the 60s are gone.

Still looking at southeast Ohio for first concern for water issues in
creeks and streams through morning. This concern expands into
remainder of the area today as strong frontogenetic forcing acting
on a moist fetch sloped behind the surface cold front amid a Stout
upper level jet...will allow for periods of heavy rain into the
afternoon hours. Worried about snowpack release in the mountains
into the morning hours with high dewpoints and a stiff wind through
much of Tuesday.

Trend in the models...particularly the NAM is for slightly colder
air aloft tonight across The Lowlands. This would limit the
significant sleet accumulations and confine them more across southeast
WV as the next wave throws significant moisture in the cold
sector. This would support higher snowfall amounts in The
Lowlands but still not to the extent that models are suggesting
given heavy rain preceding it. There is also a freezing rain concern in the
mountains late tonight and in particular our SW Virginia counties where
one to two tenths of ice accretion is possibly by 12z Thursday.

As for timing of changeover across the area...not much in the way
of change from previous forecast. Still looking at this afternoon
across southeast Ohio in the form of a transition from rain to sleet to
snow. This thinking progresses southeast into the evening hours with NE Kentucky
and WV lowlands transitioning in this evening and into the
mountains around midnight. Again...the warmer air aloft will try
to hang on across SW Virginia and southeast WV...meaning more in the way of
sleet and freezing rain.

Concerning rain totals...liquid quantitative precipitation forecast looks to be a bit less than
has been expected. Generally looking at 1 to 1.5 inches of rain
before the changeover with lollipops of 2 inches possible. That
will still cause some problems...especially in the mountains.

As for headlines...will be expanding Winter Storm Warning to cover
remainder of the north WV lowlands and north mountains. Still debating on
how to handle the Coal fields into southeast WV and SW Virginia given more in
the way of sleet and ice.


Short term /Thursday through Friday night/...
models are a bit slower with the system pulling out on
will linger higher probability of precipitation a bit longer. Although still some
differences between the models in precipitation type change over
times...feel that snowfall amounts will support warning criteria
another tier of counties will upgrade. From McDowell
and Wyoming counties into southwest Virginia...think the change over
will occur to late for warning will go with an
advisory for these counties.

High pressure builds in Thursday night...allowing for some decent
late night radiation. With snow expected to be on the ground...will
go below MOS guidance numbers for lows..


Long term /Saturday through Tuesday/...
high pressure in place to start the long term period...gradually
being squashed to the south as an upper level shortwave trough drops
through the western Great Lakes Sunday. Models struggling some with
this feature...both in speed and just how far south precipitation
with this will make it. Have another 500mb shortwave trough
following the first around Monday. 00z European model (ecmwf) tries to keep these to
features separate...while GFS does not have much of a break between
them. Ended up with a near 50/50 blend of GFS/European model (ecmwf) through the long
term for probability of precipitation. Generally stuck close to wpc for temps/winds.


Aviation /12z Wednesday through Sunday/...
heavy rain could fall along the baroclinic zone aloft behind the
surface front...sending aviation conditions into IFR or worse into
late Wednesday. Rain will transition into a mix and then snow from
west to east Wednesday afternoon into Thursday with IFR

Strong SW low level jet of around 50 kts will wane through morning and flow
veering to west direction while surface flow will generally be out of
the northwest and light on the order of 5 to 10 kts.

Forecast confidence and alternate scenarios through 12z Thursday...

Forecast confidence: medium.

Alternate scenarios: lowering of flight categories to MVFR/IFR will

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 11 12 13 14 15 16 17 18 19 20 21 22
EST 1hrly 06 07 08 09 10 11 12 13 14 15 16 17
crw consistency l l l l l l M M M h h h
heights consistency l l h h h M M M M h h h
bkw consistency h h h h h M l l l l h h
ekn consistency M l l l l l l l l h h h
pkb consistency l l l l l h h h h h h h
ckb consistency l l l l l l l l l M h h

After 12z Thursday...
IFR possible in rain Wednesday night...under rain/sleet or snow.
IFR in snow showers Thursday.


Rlx watches/warnings/advisories...
WV...Flood Watch through Thursday morning for wvz005>011-013>020-
Winter Storm Warning from 7 PM this evening to 7 PM EST
Thursday for wvz005>008-013>020-024>032-035>040-046-047.
Winter Storm Warning from 4 PM this afternoon to 1 PM EST
Thursday for wvz009>011.
Winter Weather Advisory from midnight tonight to 7 PM EST
Thursday for wvz033-034.
Ohio...Flood Watch through Thursday morning for ohz066-067-075-076-
Winter Storm Warning from 4 PM this afternoon to 1 PM EST
Thursday for ohz085>087.
Winter Storm Warning from 1 PM this afternoon to 1 PM EST
Thursday for ohz066-067-075-076-083-084.
Kentucky...Flood Watch through Thursday morning for kyz101>103-105.
Winter Storm Warning from 7 PM this evening to 7 PM EST
Thursday for kyz105.
Winter Storm Warning from 4 PM this afternoon to 1 PM EST
Thursday for kyz101>103.
Virginia...Flood Watch through Thursday morning for vaz003-004.
Winter Weather Advisory from midnight tonight to 7 PM EST
Thursday for vaz003-004.


near term...30
short term...rpy

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