Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston WV
152 am EST Wednesday Jan 28 2015
high pressure today. Low pressure Thursday. Upslope snow likely
Thursday night into Friday northeast mountains. High pressure
Near term /through tonight/...
a high pressure system will build over the region today...eroding
the remaining clouds this morning. With the core of the low level
cold air in layers not represented well by the coarser resolution
models...will stay closer to the met MOS for highs today.
For tonight...higher clouds push into the forecast area in advance
of the next system. Winds are expected to be calm early in the night
in the eastern counties...so expect some decent radiation. Later in
the night winds should pick up. This makes low temperatures
especially tricky. Will go toward the warmer MOS in the west where
clouds and winds will move in first...and go toward the colder side
of MOS in the east where some snow is on the ground and decent
radiation expected early.
Short term /Thursday through Friday/...
surface high will remain in control of our weather Wednesday
night...before a fast moving clipper system approaches the area
from the west. A nearly steady temperature trend is foreseen
Wednesday night with a slight warm up during the early Thursday
morning horus per warm air advection aloft. Expect night temperatures to remain
in the middle to upper 20s...warming up to middle to upper 40s by
Thursday as turns from the southwest ahead of the next system.
A low pressure system will move just north of the area on
Thursday trailing cold front sweeping through Thursday evening...so
County Warning Area would briefly be in warm sector. Warm advection is suggested
by models on Thursday with h850 temperatures reaching 4c under
southwest flow. Precipitation should reaches southeast Ohio by 18z
Thursday in the form of rain. Then...cold advection rushes in from
the northwest transitioning precipitation into a mix and ultimately to all
snow. The northwest flow will turn on the upslope machine over the
northeast mountains Friday night into Saturday with up to 7 inches
of snow falling over the highest ridges in a period of 24 hours or
so. Elsewhere...snow amounts will range from a dusting to 1 inch.
Continued to mentioning 2 to 7 inches of snow over the northern mountains
in severe weather potential statement for possible advisory. Although County average seems not to meet
criteria only beyond 12 hours. Lows will dip into the 20s most
A strong high builds starts impacting the area late Friday night
into Saturday...putting an end to the snow showers. Highs will
generally be in the upper 20s and low 30s Friday...with lows into the
teens Friday night.
Long term /Friday night through Tuesday/...
Canadian high pressure dominates Saturday with sunshine and below
normal temperatures. The next system affecting US Sunday into
Monday is a two fold event. A we have seen so often this winter...we
have a split flow regime in which we cannot quite phase the
northern stream and southern stream. The main feature will be a
shearing out upper trough and associated low pressure system from
the southern rockies...lifting northeast across the Ohio Valley
Sunday...in advance of a northern stream short wave and cold front
for Sunday night and Monday. While the models do not quite phase the
systems...all forecast the surface low to track just to our north
Sunday. This will allow enough warm air northward for primarily a
rain event on Sunday...although initially there could be some ice
especially on east facing slopes of the mountains. However...the
precipitation could be generally snow over our far northwest
portions of our southeast Ohio counties as they will be close to the
track of the low. In any case...temperatures will still average
below normal. Given the fast flow aloft and lack of phasing...will
go with the faster GFS model...which tracks the surface low up through
central Ohio Sunday and brings the following cold front rapidly
across the area Sunday night. Rain will change to snow behind the
cold front Sunday night and taper off from west to east Monday...as
much colder air rushes back in. Look for well below normal
temperatures for early next week.
Aviation /07z Wednesday through Sunday/...
stratus deck and light snow will gradually dissipate this
morning...with the western slopes of the mountains holding the
clouds the longest. After the clouds dissipate...expected VFR
conditions through tonight.
Forecast confidence and alternate scenarios through 06z Thursday...
Forecast confidence: medium on the timing of the stratus deck
Alternate scenario: timing clearing could 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.
Date Wednesday 01/28/15
UTC 1hrly 06 07 08 09 10 11 12 13 14 15 16 17
EST 1hrly 01 02 03 04 05 06 07 08 09 10 11 12
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 M 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 06z Thursday...
IFR conditions possible Thursday/Thursday night across the entire
region and then in the mountain counties on Friday morning in snow
switching to rain.