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fxus61 krlx 101139 
afdrlx

Area forecast discussion
National Weather Service Charleston WV
639 am EST Tue Dec 10 2019

Synopsis...
cold front passage with rain changing to snow. Turning colder
Tuesday with rain turning to snow in the evening. Dry and cold
for Wednesday and Thursday. Next system approaches Friday.

&&

Near term /through tonight/...
as of 635 am Tuesday...

Rainfall amounts of 0.25 to 0.50 inches has fallen over the Ohio
Valley during the overnight. Cold front now working through the
West Virginia lowlands this morning, with some breaks in the
rain upstream to the southwest. Temperatures starting to fall,
most noticeably through southeastern Ohio and along the Ohio
River.

As of 250 am Tuesday...

Despite the amount of synoptic scale forcing in the form of jet
streak right rear quadrant effects and strong mid level f-gen.
Ultimately the speed of the exiting moisture and the pronounced
lack of moisture depth into the Crystal growth layer is going to
end up being a limiting factor for snow in both the lowland
areas and the mountains. In the end, quantitative precipitation forecast amounts are down, and
subsequently the snow amounts through tonight. Not much in terms
of changes from the timing of precipitation type transition
from rain to snow, as a non diurnal continuously falling
daytime temperature will dictate much of this. A significant
portion of the western County Warning Area will not get snow accumulations or
any snowfall for that matter.

Western zone skies likely clear out before sunrise Wednesday.

&&

Short term /Wednesday through Thursday night/...
as of 350 am Tuesday...

Bulk of the moisture will be on the other side of the
Appalachians by Wednesday morning as high pressure builds in
from the southwest. This surface feature quickly exits toward
New England on Thursday, allowing for southerly flow and
warming temperatures to ensue. Clouds will be on the increase
Thursday evening ahead of the next weather disturbance arriving
for the end of the work week.

&&

Long term /Friday through Monday/...
as of 350 am Tuesday...

A disturbance developing in the Gulf will proceed northward at
the start of the long term period, with precip encroaching from
the south Friday morning. Discrepancies have unfolded among
latest model updates in regards to this system and pop
intensity/coverage, so stuck with a Happy medium produced by
central guidance. There will be a brief period for sub-freezing
precip with the onset of this event, but widespread rain takes
over for all areas outside of the highest ridgetops by Friday
afternoon as temperatures rise for the day. Elected to subdue
snow totals for the mountains for the time being given the
uncertainty between models and the small coverage of
accumulations.

The active weather pattern continues into the weekend with a
succession of frontal boundaries crossing through the region.
Afternoon highs peak Saturday in the low 50s for The Lowlands
before dropping back into the 30s/40s by the start of the new
work week. Another disturbance treks through the Ohio Valley
late Sunday into Monday, with surface temperatures dictating
precip types through the remainder of the period.

&&

Aviation /12z Tuesday through Saturday/...
as of 635 am Tuesday...

On and off rain through today, clearing northwest to southeast,
and changing from rain to snow, mainly for the mountains.

Ceilings deteriorate to IFR at times in rain today, with
visibilities mainly in the MVFR range and wind gusts 15-25kts
behind a cold frontal passage. Wind directions to change 40-70
degrees with the passage of the front. IFR in snow tonight at
ekn/bkw. Snow should stay east of the crw-ckb line.

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

Forecast confidence: low to medium.

Alternate scenarios: observations of likely to bounce in and out
of rain. Timing of change to snow could vary slightly. Wind
gusts may need to be increased slightly.

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 Tuesday 12/10/19
UTC 1hrly 10 11 12 13 14 15 16 17 18 19 20 21
EST 1hrly 05 06 07 08 09 10 11 12 13 14 15 16
crw consistency h h M h h h h h h h h h
heights consistency h h h h h h h h h h l l
bkw consistency h h l h h h h h M M M M
ekn consistency h h M M h h h M M h h h
pkb consistency h h h h h h h h h M M h
ckb consistency h h h h h h h h M h h h

After 12z Wednesday...
IFR possible in rain late Friday into Friday night in rain.

&&

Rlx watches/warnings/advisories...
WV...none.
Ohio...none.
Kentucky...none.
Virginia...none.

&&

$$
Synopsis...26/mek

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