Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston WV
344 PM EDT Sat Oct 10 2015
high pressure drifts across the forecast area tonight through
Sunday night. The next cold front passes Monday night. High
pressure Wednesday and Thursday.
Near term /through Sunday/...
broad area of high pressure builds over the forecast area with the
only concerns being overnight fog and potential for frost at
highest elevations. Regarding the latter...with cloud cover slow
to mix out...opted to keep temperatures a little warmer than prior
forecast which puts them in the upper 30s in the highest mountain
valleys. As far as fog...generally put some in most river valleys
especially in the 11-14z timeframe as clear skies and light winds
form a weak subsidence inversion.
Short term /Sunday night through Tuesday/...
not much to speak of in terms of timing changes with the cold front
for the Monday night time frame. The question still remains with the
available moisture in the low levels. Showers are expected...but the
semi lack of frontogenetic forcing with the front and the moisture
issue warrants only high end chance for now...and is consistent with
the neighboring offices.
Counting on a quicker exit to this cold front and its associated low
level moisture...focusing on 925mb relative humidity values off the NAM. Do not
leave any low cloud decks lingering in the mountains...as this
should be of the clean sweep variety. Temperatures come back down
Tuesday in the wake of the front in west northwesterly surface
winds...but insolation should keep that value in check. Expect flat
fair weather cumulus in the cold pool behind the front with
Long term /Tuesday night through Saturday/...
cool high pressure starts to build into the region on Wednesday.
A weak upper level feature will passes to our north on Wednesday
as well. Just expect some clouds with this across the northern
zones. High pressure will again be in control through Thursday. A
weak upper level system will pass over the Great Lakes late
Thursday and Friday. Its trailing cold front will move through the
region on Friday as well. Moisture is limited with this system and
only put slight chance probability of precipitation in across the north late Thursday night
and Friday morning. Front and any showers will quickly exit the
region by Friday afternoon and evening. Behind this system...a
very cool high pressure system will build in across the region for
the weekend. Some frost may be possible Saturday night into early
Sunday morning as temperatures are forecasted to dip into the 30s. High
pressure will remain in control through the early part of the work
week with a gradual warmup expected.
Aviation /20z Saturday through Thursday/...
IFR valley fog likely overnight tonight especially around rivers
as winds diminish under high pressure. Models are having a bit of
rough time with the IFR conditions around kbkw...so based on
satellite trends kept them in the crud until 21z.
Forecast confidence and alternate scenarios through 18z Sunday...
Alternate scenarios: MVFR stratocumulus may reform over the
mountains tonight. There may be more valley fog late tonight than
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 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1hrly 14 15 16 17 18 19 20 21 22 23 00 01
crw consistency M h h h h h M h h h h M
heights consistency h h h h h h h h h h h h
bkw consistency M M M M M M M M M M M M
ekn consistency M M M M M M h h h M M 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 18z Sunday...
no widespread IFR expected at this time.