Scientific Forecaster Discussion
fxus61 krlx 220828
Area forecast discussion
National Weather Service Charleston WV
328 am EST Fri Nov 22 2019
cold front brings rain under gusty winds today and exits by late
evening. Another low Saturday brings more widespread rain. Dry
start to the new week.
Near term /through tonight/...
as of 325 am Friday...
A cold front crosses this morning spreading light rain and
gusty winds west to east through this afternoon. Rainfall
accumulations should Max up to half an inch over central and
southern West Virginia, including extreme southwest Virginia. Few snow
flakes could be seen across the higher elevations northeast
mountains late tonight. Models consensus indicate saturation at
low levels suggesting widespread low level clouds and fog from
mid morning through late afternoon across central and eastern
Southwesterly winds will increase to 10 knots ahead of the front,
shifting from the northwest up to 22 knots through mid afternoon.
Winds should diminish by late afternoon remaining gusty at higher
elevations through early tonight.
Dry conditions expected tonight with temperatures dropping below
freezing, from the upper 20s northern sections, to the mid 30s
central WV and tri-state area, to the upper 30s extreme
southern coalfields of WV and southwest Virginia.
Short term /Saturday through Sunday night/...
as of 300 am Friday...
Most models are in line with a system pushing up from the south
and entering our southern counties at around 12z Saturday.
Although the GFS is slightly slower, went with a blend of
models consensus and have precipitation spreading south to
north increasing progressively with likely pops areawide by
late afternoon. The surface low associated with this system is
progged to move directly through the area and slightly to the
west which will promote warm air advection and southeasterly
flow. Due to the southeasterly flow, downsloping over the
mountains can cause quantitative precipitation forecast amounts to be fairly low over the event.
Not expecting much with most places not even forecast to break
half an inch. Most, if not all, precipitation will be rain as
weak lifting and warm air will plague snow growth.
Have rain tapering off late Saturday night and then turning to a
wintry mix for Sunday morning in certain areas like northeastern
WV and along the mountains. Most of the snowflakes will fall in
these areas, however should only accumulate in small amounts
confined to mountain tops. Anywhere else the snow will melt as
ground and Road temps are too warm. The system finally exits
late Sunday morning/afternoon leaving behind only a shallow
layer of moisture which will create very little in the way of
snow or rain at that Point. May see some flakes or light
drizzle/freezing drizzle confined to the mountains, but since
confidence was low in moisture profile went ahead and accepted
central guidance and left in rain/snow there.
All in all there may be enough time for the highest peaks and
ridges to receive an accumulation of an half an inch of snow,
however really not expecting much of anything elsewhere. This
should be a very little impactful event and really only small
inconveniences are possible.
Temperatures should'nt be affected too much after the
aforementioned system exits Sunday afternoon bouncing from
slightly cooler than seasonable to right around average until
Long term /Monday through Thursday/...
as of 310 am Friday...
High pressure gives the region some reprieve from the last
system until early morning on Wednesday. After seasonable
temperatures we experience a cooling by a just a few degrees
from average into the weekend. Wednesday's system will be
different from the last, in that the parent low will move past
the area well to the north, however will not filter in cooler
air over the area. This time temperatures will actually be
slightly warmer aloft, not boding well for snow probability.
Still far out to tell although this one looks to be an all rain
event except for maybe in the highest mountain peaks.
Regardless, this system exits in a hurry and basically rips
through the area in just about 12 hours as strong high pressure
moves right in protecting the area for Thanksgiving and into
the weekend. The GFS hints at a very extensive weather maker
for the second half of the weekend although other models have
Aviation /09z Friday through Tuesday/...
as of 200 am Friday...
Period starts with widespread VFR conditions. However, metars
and satellite imagery indicate a solid cloud deck shortly above
3,000 feet at most sites. Wx charts show a cold front
approaching from the northwest. Model consensus suggests cold
front positioning along the Ohio River by 12z Friday. Light
southwest wind ahead of the front will become gusty before
shifting from the northwest and gusting up to 22 knots behind
the front, lasting through at least 18z. Winds should diminish
some this evening becoming light from the north and near calm
later Friday night.
Radar imagery indicate a broad area of stratiform precipitation
ahead of the cold front across central KY, streaming northeast
towards southeast Ohio and WV. Light rain should arrive at heights
with Manly MVFR conditions around 09z. Models suggest MVFR
ceilings becoming IFR or worst across most sites along and ahead
of the cold front from 14 to 18z.
Conditions should improve from west to east across The Lowlands
late this afternoon, and over the eastern mountains later this
evening. Bkw may hold on to IFR stratus through 00z Saturday.
Forecast confidence and alternate scenarios through 06z Saturday...
Forecast confidence: high.
Alternate scenarios: timing of deteriorating conditions may vary
an hour or two early Friday morning.
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 Friday 11/22/19
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 h h h h h h h M M h h
heights consistency h h h h h h h M l M M l
bkw consistency h h h M M h h h h l M h
ekn consistency h h h h h h h h M h h h
pkb consistency h h h M h M h h M M M h
ckb consistency h h h h h M M h h M M M
After 06z Saturday...
IFR possible Saturday into Saturday night, in rain, and possibly
brief snow as it ends.