Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston WV
613 am EDT Monday Oct 20 2014
a cold front crosses early Tuesday. Low pressure meanders along
the East Coast Wednesday through Thursday. High pressure builds in
Near term /through tonight/...
high pressure exit east...leaving the area in a zonal flow aloft.
However...an upper level trough will approach from the west with
its associated cold front. The front will bring good chance for
rain showers mainly tonight into early Tuesday.
Radar echoes will likely be seen ahead of the front...but at
start the precipitation will not reach the ground and fall as virga during
the morning hours. Precipitation will increase in intensity as the column
gets saturated to produce rain showers today spreading from west
to east...more numerous during the evening hours.
Temperatures will continue in the cool side through at least middle
week...generally around 40 or in the upper 30s at night...and 60
to the middle 50s during the afternoons. Used met guidance with few
Short term /Tuesday through Thursday night/...
a cold front moves across the region on Tuesday as previously
advertised. There is good consistency with this feature. An upper
level low develops in the region overnight Tuesday into Wednesday.
The big questions will be where exactly does this low develop and to
where it will meander around. At this time will go with the
scenario that it will be east of the forecast area on Wednesday.
There is plenty of moisture on the backside of this low so will
leave chance probability of precipitation east and slight chance from the Ohio River and
west. The 540 mb thickness line will be across the northern
mountains Wednesday night and expect some light snow showers or
flurries across the mountains. Don/T expect enough to measure. If
the low placement changes there could be some snow accumulations
over the higher terrain. Expect a high to develop over the Great
Lakes on Wednesday and this will move east on Thursday...finally
drying the forecast area out on Thursday.
For temperatures went with a blend of guidance through the forecast
Long term /Friday through Sunday/...
generally looking at dry and quiet weather in the extended. Area looks to
remain under northwest flow aloft...on back side of mean trough. Any
disturbances traversing through the trough look to remain well north of the
area. All in all...a nice and mainly sunny seasonal extended period.
Expect good radiational cooling at night which may result in some
frost come Thursday morning. Should see more of a Ridge Valley temperature
split at night by this weekend amid some warm air advection just off the surface.
Aviation /10z Monday through Friday/...
freezing fog developed around 09z at ekn for LIFR conditions...while
dense fog developed at crw at 10z. VFR conditions prevailed across
other sites...expected to continue through the day today. LIFR/IFR
conditions at ekn and crw will improve by 13-14z as the fog lift
Clouds will thicken today as light showers...ahead of a cold front
approaches from the west.
Upper level trough and surface cold front approach Monday from the west.
There is a good chance for showers late Monday in several broken bands.
Visibility restrictions are not coded due to the lack of radar coverage
anticipated...but brief MVFR visibility can occur.
Surface flow will become southwest today and a bit gusty later this
afternoon. Coded gusty winds up to 20 knots at most sites around
Forecast confidence and alternate scenarios through 12z Tuesday...
Forecast confidence: medium to high.
Alternate scenarios: MVFR mist / IFR fog could briefly form at ekn
and pkb. There may be brief MVFR visibility restrictions in showers late
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 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1hrly 07 08 09 10 11 12 13 14 15 16 17 18
crw consistency h h h h h h h h h h h h
heights consistency h h h h h h h h h h h h
bkw consistency h h h h h h h h h h h h
ekn consistency l l M l h h h h h h h h
pkb consistency M 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 12z Tuesday...
IFR in low stratus Tuesday into Wednesday...especially at night.
WV...frost advisory until 10 am EDT this morning for wvz015>020-