Scientific Forecaster Discussion
fxus61 krlx 180634
Area forecast discussion
National Weather Service Charleston WV
234 am EDT Wed Oct 18 2017
dry high pressure with cool mornings and warm afternoons, with
temperatures moderating through the weekend. A cold front
crosses on Monday.
Near term /through tonight/...
as of 235 am Wednesday...
Looking at a rather Carbon copy day today from yesterday, with
slightly warmer temperatures, as high pressure slides eastward,
and a light southerly flow takes hold. Kept temperatures a
couple of degrees above guidance due to expected dry air and
ample sunshine expected. Will be another day with low relative
humidities, with humidities dipping into the 20 to lower 30
percent range again area wide. Winds however should remain
Tonight, not quite as cold as recently, but will still see some
patchy frost, mainly in the mountainous counties where growing
season has ended. River Valley fog is also expected late
Short term /Thursday through Friday night/...
as of 230 PM Tuesday...
A sfc high pressure will extend from the adjacent coastal
waters of the mid Atlantic, east and south into WV Wednesday
night. The high center shifts overhead as it strengthened
controlling the weather conditions. Very dry conditions
expected through Friday night.
Minimum relative humidity values will dip into the 20s in parts
of the area Wednesday afternoon, with 30s again widespread
Thursday afternoon, becoming more confined to the mountains for
By Saturday night, the high drifts east as an approaching cold
front tightens the pressure gradient to pump moist and warmer
air into the area under southwest flow.
Long term /Saturday through Tuesday/...
as of 230 PM Tuesday...
High pressure continues in control on Saturday through Sunday
night. Will have to monitor each afternoon after mixing could
bring low relative humidity into the mid 30s. An increase in southwest flow is
expected as the front approaches. An upper level trough and
surface cold front to cross from the west Sunday night into
Monday. Models are in agreement with the timing of frontal passage as an
upper level through passes through.
After drying out behind the front Monday night, the slowing,
deepening upper level trough over the area spells lots of
clouds, and the chance for showers into Tuesday.
Guidance suggests a warming trend through Sunday, followed by
temperatures falling back to normal early next week.
Aviation /07z Wednesday through Sunday/...
as of 120 am Wednesday...
Still expecting vlifr fog to develop in river valleys generally
after 07-09z. Fog will dissipate by 14z, with a return of VFR
conditions with light surface winds area wide.
Forecast confidence and alternate scenarios through 06z Thursday...
Forecast confidence: medium.
Alternate scenarios: less fog may develop tonight than currently
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 10/18/17
UTC 1hrly 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1hrly 02 03 04 05 06 07 08 09 10 11 12 13
crw consistency h M l l l l l l l h h M
heights consistency h h h h M M M M h h h M
bkw consistency h h h h h h h h h h h M
ekn consistency l l l l l l l l l h h M
pkb consistency h M l l l l l l l h h M
ckb consistency h h h h l l l M h h h M
After 06z Thursday...
dense valley fog possible each morning this week.
WV...frost advisory until 9 am EDT this morning for wvz005>011-
Ohio...frost advisory until 9 am EDT this morning for ohz066-067-075-
Kentucky...frost advisory until 9 am EDT this morning for kyz101>103-105.
Virginia...frost advisory until 9 am EDT this morning for vaz003-004.