Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston WV
739 PM EDT Friday Oct 9 2015
a cold front brings gusty storms as it crosses the area. High
pressure this weekend. Next cold front passes Monday night and a
weaker one middle week.
Near term /through Saturday/...
models in reasonable agreement on handling upper trough and cold
front dropping southeast across the area late this afternoon and
tonight. It appears the southern end of the upper trough does
close off...but well southeast of the area. Thus...the cold front
looks quite progressive this afternoon and early tonight. A well
organized line of showers and thunderstorms have developed and at
18z are along the Ohio rive with the cold front. This line and
front will continue eastward the remainder of the afternoon and
evening...with some storms containing gusty winds. The front will
arrive along the i79 corridor around 21z and in the mountains
around 01z. Will have Cat probability of precipitation for this line...and with the upper
trough lagging somewhat behind the front...will continue a chance
of lighter showers for a few hours after frontal passage. As the
southern end of upper trough slows...will hang onto a few showers
in the southeast until around midnight. Even though precipitation ends
tonight...lots of low clouds will linger in the cold advection
well into Saturday morning. Winds may die down enough for some
River Valley fog...but the most significant fog will be in the
mountains with the upslope component to the flow. On Saturday...a
relatively slow improvement process from west to east...but
abundant sunshine will return to at last the northwestern half of
the area during the afternoon as Canadian high pressure takes
control. High temperatures Saturday will return to normal values
Short term /Saturday night through Monday/...
high pressure build in...then drifts off to the southeast allowing
the southerly flow to return to the central Appalachians. This is
after a decent radiational cooling night forecast for Saturday
night...in which mountain valleys will likely see 30s.
Flow aloft aloft turns zonal...then tightens up ahead of the next
trough/cold front combo moving in towards the end of the short term
forecast period on Monday. NAM is more underwhelming with the
available moisture and forcing with the front on the front end of
the system. Operational GFS and European model (ecmwf) ramps up the quantitative precipitation forecast quite a bit
beyond 00z Tuesday...so will have to wait to see if the NAM follows
a similar path when it falls within the scope of the model.
Forecast trends are climbing temperatures...increasing clouds late
Monday...and chances for showers after 18z Monday entering the
southeast Ohio zones.
Long term /Monday night through Friday/...
a weak cold front passes through the region Monday night and
quickly exits by Tuesday morning. 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
persist over our area into the weekend. As weak systems pass to
Aviation /00z Saturday through Wednesday/...
00z Friday through 00z Saturday...
latest radar mosaic shows band of showers and storms has pushed
southeast of the area. However...some scattered storms continue to
push southeast across The Lowlands.
Some local areas of IFR conditions continue...mainly in the
mountains...with VFR/MVFR conditions elsewhere.
Behind the front...showers will linger especially across the
south as an upper disturbance comes across with MVFR ceilings
becoming dominant. Still feel showers in the south and east should
generally end by 06z. MVFR conditions are then expected overnight
in ceilings/fog low lands...and general IFR/LIFR conditions in
ceilings/fog in the mountains.
For Saturday...conditions will slowly improve in the
morning...but becoming VFR by 18z low lands and MVFR ceilings
Forecast confidence and alternate scenarios through 00z Sunday...
Alternate scenarios: timing and extent of low stratus and fog
behind the front tonight 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 21 22 23 00 01 02 03 04 05 06 07 08
EDT 1hrly 17 18 19 20 21 22 23 00 01 02 03 04
crw consistency M M M M M M M M M M M M
heights consistency M M M M M M M M M M M M
bkw consistency M M M M M M M M l l l l
ekn consistency M M M M M M M M l l l l
pkb consistency M M M M M M M M M M M M
ckb consistency M M M M M M M M M M M M
After 00z Sunday...
IFR in valley fog possible late Saturday night into Sunday