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Area forecast discussion 
National Weather Service Binghamton New York
1006 PM EDT Thursday Aug 28 2014

cool high pressure will expand eastward out of the Great Lakes and
Canada, bringing fair weather to New York and PA through Friday. A storm
system will move through northern New York on Saturday, with a chance
for a thunderstorm Saturday evening, and a better chance for
thunderstorms Sunday.


Near term /through Friday night/...
10 PM update...
no significant changes to forecast updates this evening other
than to adjust for some passing cloudiness sliding south...and
also some higher cirrus moving in from the western Great Lakes
region. Cold advection across Lake Ontario to be offset by dry
airmass...however did bump up some sky cover percentages to
account for some late Night Lake cloudiness. Temperatures bouncing
around this evening as they drop rapidly under fair radiational
cooling conditions across the western half of the area...while
scattered areas of clouds keep temperatures in check across the east.
Should see temperatures steady out for a chilly night in the middle-upper 40s
over the next few hours.

300 PM update...
high pressure over central Michigan will control our weather
during this period. Moisture trapped below an inversion combined
with sunshine has produced ample stratocu clouds today. These
clouds have already shown signs of breaking up a bit, and will
continue to do so even more substantially as we head toward
sunset. With high pressure in control, a clear sky/calm condition
night will provide for some chilly air! Most locations will be in
the 40s, with near 40 in our normally colder spots. With temperatures
falling so low tonight, River Valley fog will be likely after
midnight. High pressure overhead Friday will bring US a lot more
sunshine. Just look at Detroit, Michigan now for our weather tomorrow.
Highs with the added sunshine will generally be in the 70s.


Short term /Saturday through Sunday/...
300 PM update...

Model guidance continues to slow down the arrival of precipitation
over the weekend, with Saturday looking mostly dry for everyone,
and Sunday being the better bet for rain. I continued the lowering trend
of the past few days and only show a 20% chance for storms (finger
lakes) through sunset Saturday evening due to the slower timing.

While showers are possible late Saturday night, all model guidance
shows that Sunday is the highest threat for rain and
thunderstorms. Despite plenty of clouds around, the NAM, Euro, and
GFS all show MLCAPES above 500 j/kg, and in some cases above
1,000. Severe threat would appear to be limited given the cloud
cover. At this point a bit too early to tell for sure, with model
guidance showing a wide range in 0-6 bulk shear values between 25
(minimal) and 40 kts (moderate). For now our current 50%-60%
chance for storms during the day looks good.


Long term /Sunday night through Thursday/...
medium range models are in fair agreement through the extended
period indicating a zonal upper level flow along the US/Canadian
border for much of the period. Sunday night through Monday night,
area will be in southwest somewhat moist/mild flow with chance probability of precipitation
for convection. On Tuesday a surface cold front will pass through the
northeast followed by a drier/cooler airmass. Will advertise high
chance probability of precipitation for thunderstorms on Tuesday followed by dry weather for
the remainder of period. Temperatures will run 5-10 degrees above
normal until frontal passage on Tuesday when seasonal temperatures return.


Aviation /02z Friday through Tuesday/...
00z Friday update... other than an expected period of fog at kelm towards daybreak
(ifr/LIFR from about 08-13z)...VFR should rule this period. This is a
somewhat low confidence fog forecast for kelm...with fairly strong low-
level dry advection continuing at this time. However...indications are still
that the winds will slacken considerably later tonight...allowing an
opportunity for good radiational cooling/fog development.

For the most part...surface winds should remain at or below 5 knots.


Friday night and Saturday...primarily VFR.

Sat night through Tuesday...possible brief restrictions from scattered
rain showers- thunderstorms and rain...mainly on Sunday and Tuesday.


Bgm watches/warnings/advisories...
New York...none.


near term...heden/jab
short term...heden
long term...rrm

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