Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Binghamton New York
1036 am EDT Wednesday Oct 1 2014
a weak storm system will keep a slight chance of showers over our
region this morning. High pressure will return with dry weather for
Thursday, and then a strong front will bring rain and cooler
temperatures to the area Friday night.
Near term /until 6 PM this evening/...
1035 PM update...
the outer bands of showers associated with a disturbance moving up
the coast are just now moving into the Catskills. Meanwhile
isolated showers have popped up over portions of nepa. A 20 to 30%
chance of showers still looks on track today for everyone except
the western Finger Lakes up to near ksyr. I increased cloud cover a
bit otherwise temperatures and going forecast are on track. The previous
afd is below.
315 am update...
ul trough is progressing over the forecast area this morning while diffuse surface
front hangs up to the east. This will keep a chance of a few
showers over the forecast area this morning, especially east of I-81.
Skies will gradually clear this afternoon with temperatures
rebounding to around 70 degrees based on 925mb 12c-13c temperatures.
830 PM update...
500 mb low moving into western PA at this time with deep easterly flow
evident on vwp and convective elements moving west. Convection
currently most widespread across The Finger lakes region and
central southern tier. This is in an area of better instability,
middle level lapse rates and low level convergence. Activity will
continue to diminish in areal coverage and intensity during the
next couple of hours as atmosphere becomes more stable. Will
continue with likely probability of precipitation far west and chance elsewhere then lowering
probability of precipitation to chance/slight chance after midnight. Included patchy fog across
the southern two thirds of forecast area due to evening rainfall and weak
mixing. Overall forecast in good.
Short term /6 PM this evening through Friday night/...
high pressure through Friday with fair weather, slightly above
normal temperatures, and morning fog. Combination of low sun angle
and long nights makes this time of year one of the best for
fog formation. River valleys should fog in nightly after 6z.
Kept to the idea of a slower frontal progression, as the models
are sticking to this projection. Running likely probability of precipitation Friday night
as vigorous ul trough swings into Ohio Valley and powerful cyclone
pulls out of the Great Lakes region. Plenty of moisture will be
drawn up ahead of the storm, so likely probability of precipitation look reasonable this
Overnight timing minimizes thunder threat. Middle level lapse rates
are in the 5c-6c range...meager to modest. Low level lapse rates
are prognosticated by nam12 around 4c. Bulk shear is pretty good with
0-6km values of 30-35 kts but it appears little to no instability
will be in place.
Long term /Saturday through Tuesday/...
2 PM update...
500 mb trough digging in to start off the extended with widespread light-
moderate rainfall expected as addnl WV mvs up late Friday night.
Frontal passage occurs on Saturday with just chance probability of precipitation through the long term as
ul trough remains through the early part of next week. Have sided with wpc
guidance but have knocked categorical probability of precipitation down to likely Friday night as
it is too far out to go near 100 at this point.
Aviation /15z Wednesday through Sunday/...
12z Wednesday update... widespread restrictive conds this morning will
slowly improve by 15-17z. IFR is most likely at kelm...with brief
periods of such also possible at kith and kbgm.
VFR should return area-wide by afternoon...with ceiling bases lifting by
this time. Isolated-scattered showers could be at play through early to middle
afternoon...especially in the vicinity of kbgm and kavp...but they are
likely to be unrestricted...should they even occur.
Later tonight...areas of fog should develop once again...most prevalent in
the twin tier river valleys. Thus...kelm is expected to drop at least
below alt mins. Some restrictions could also impact
krme/kith/kbgm/kavp in the pre-dawn period.
Thursday and Friday...VFR...except for early morning valley
fog/lower ceilings...especially kelm/kith/kbgm.
Friday night...widespread restrictions possible from rain showers.
Sat/sun...mainly VFR. Some -shra possible.