Scientific Forecaster Discussion
fxus61 krlx 220236
Area forecast discussion
National Weather Service Charleston WV
936 PM EST Thu Nov 21 2019
rain overspreads the area overnight and exits midday Friday, as
a cold front and wave move through. Another low Saturday brings
more widespread rain. Dry start to the new week.
Near term /through Friday/...
as of 935 PM Thursday...
Band of light showers diminished a bit further as they
encountered the dry air in the mountains, with additional
spotty light showers or sprinkles out across the WV lowlands.
Temperatures continue to run a bit high this mild night, with
further adjustments made.
As of 730 PM Thursday...
Adjusted temperatures up a bit for tonight. A weak, mainly dew
point boundary continued to meander in the mountains, with very
dry air east of it. Made down Ward adjustments to dew points
there for tonight. A band of showers headed for the mountains
will encounter the very dry air there tonight, and rain does not
become widespread in the forecast area at large until late
overnight. Winds were starting to become gusty across the north,
behind the band of showers.
As of 100 PM Thursday...
A cold front will sag through the area late tonight into Friday
before checking up somewhere across the Tennessee Valley into SW Virginia.
Light showers will moving into southeast Ohio this evening with perhaps
some sprinkles east of the Ohio River this afternoon/evening. Rain
will increasing in coverage and intensity mainly east of the Ohio
River Friday morning as a decent jet streak pivots through,
helping to provide better dynamics with the baroclinic zone.
Rain will end from northwest to southeast Friday afternoon as
the front speeds up and shifts southeast with the passing of the
upper level S/W trof. Expect a decent clearing line with this
system across southeast Ohio and northern WV as drier air advects in
throughout the column in the afternoon. Some partial clearing
may make into NE Kentucky and c WV as well. Temperatures will remain
mild overnight with a midnight high likely, followed by a non
diurnal trace Friday amid falling afternoon temperatures.
Short term /Friday night through Sunday night/...
as of 201 PM Thursday...
Aforementioned surface front is prog to stall south of the
region Friday night and then shift back north during the day
Saturday as a sfc low develops along the front. The low is
expected to deepen as it moves northeast from the lower MS River
Valley to across Tennessee and eventually across West Virginia by late
Saturday. Combination of this occurrence with an approaching
strong 500 mb trough and 110+ kt h25 jet will result in a rather wet
and chilly day for Saturday. A brief mix of rain/snow may occur
across the northern County Warning Area early in the onset of precip before
transitioning to all rain. As the surface low kicks NE, cold air
advection will kick in with the thermal column quickly cooling.
Any lingering rain should transition over to snow Saturday night
into Sunday, primarily in the mountains.
Long term /Monday through Thursday/...
as of 210 PM Thursday...
Quieter weather expected Monday before another storm system
arrives on Tuesday, bringing yet another chance of precip to the
area. After that system exits (potentially right before
thanksgiving), a couple of days of drier weather may then prevail
as high pressure tries to influence area weather.
Aviation /03z Friday through Tuesday/...
as of 730 PM Thursday...
Widespread altocu deck gradually lowers tonight, as a cold front
with a wave riding along it approaches. A band of showers east
of the Ohio River and heading for the mountains is not expected
to to cause much flight restriction tonight.
The cold front and wave will cause rain to become widespread
overnight tonight, lowering restrictions to MVFR ceilings and
visibility near dawn Friday, and then IFR for a time in rain and
fog during the daylight morning hours Friday, from northwest to
Conditions will improve Friday afternoon, again from northwest
to southeast. Visibility will improve to VFR quickly after the
rain ends, and stratus will lift into MVFR stratocu, which may
then scatter out around sunset Friday. Bkw may hold on to IFR
stratus through 00z Saturday.
Light southwest surface flow will become gusty across northeast
WV tonight, and then shift to the northwest as the cold front
passes midday Friday, and then gradually diminish through late
Friday afternoon and evening. Elsewhere, light south to
southwest surface flow will switch to northwest as the cold
front crosses Friday morning through early Friday afternoon.
Moderate to strong west to southwest flow aloft will switch to
light to moderate northwest as the front aloft crosses around
midday Friday, a little behind the surface front.
Forecast confidence and alternate scenarios through 00z Saturday...
Forecast confidence: high.
Alternate scenarios: timing of deteriorating conditions may vary
an hour or two early Friday morning. Minimum ceilings and
visibilities may vary Friday morning, and timing of improvement
Friday midday and afternoon, may 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.
UTC 1hrly 00 01 02 03 04 05 06 07 08 09 10 11
EST 1hrly 19 20 21 22 23 00 01 02 03 04 05 06
crw consistency h h h h h h h M M M h M
heights consistency h h h h h h M l h h h l
bkw consistency h h h h h h h h h h 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 l h
ckb consistency h h h h h h h h h h h M
After 00z Saturday...
IFR possible Saturday into Saturday night, in rain, and possibly
brief snow as it ends.