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Area forecast discussion 
National Weather Service Binghamton New York
202 PM EDT Wednesday Jul 30 2014

Synopsis...
an upper level disturbance will remain over the area through late
week. This weather system will keep our temperatures cooler than
normal, along with a chance of showers or thunderstorms during
the afternoon.

&&

Near term /through Thursday/...
radar continues to show a few rain showers working east-NE into The Finger
lakes region...central southern tier of New York and into Bradford
County PA. Water vapor imagery continues to show an upper level wave
working ewrd into New York and PA for the afternoon. This is coinciding
with the time of maximum heating...providing some modest cooling
aloft to enhance some instability. Storm Prediction Center mesoanalysis Page shows
mixed layer convective available potential energy of between 250 and 500 j/kg mainly west of I-81.
Models generally are showing mixed layer convective available potential energy this afternoon
around 500 to 1000 j/kg with weak to modest shear profiles. Not
anticipating any severe weather given lack of strong shear and
instability but will be adding thunderstorms and rain to grids as 12z guidc is more
unstable than 06z and 00z guidc of last night. There really isn't
much of a trigger for convection either and I believe it will
remain fairly unorganized also limiting any severe threat. All the
acvty will wind down late this evening with the passage of the
short wave to the east. I used weather forecast office bgm/S local WRF 4km version for
timing of precipitation which looks right on target. I also blended with
surrounding offices for a better consensus forecast. So will have
chance probability of precipitation for rain showers and will add thunderstorms and rain shortly.

For tonight...rain showers and thunderstorms and rain will wind down after sunset and also with
the passage of the upper level wave to the east. Then another short wave...
presently seen well in the water vapor imagery heading southward
toward Lake Superior... will cross New York and PA Thursday morning. I expect
that there will be addtnl rain showers and even some thunderstorms and rain with this
feature. Model soundings suggest some instability too. The wave
will pass east by afternoon...the time of maximum heating so not
expecting anything significant in the way of intense storms. Convective available potential energy
likely will remain at best 500 j/kg. Shear will be strong Thursday am
but in the absence of any significant focusing ll boundary it is
possible that the convection has a hard time going given the lack
of significant instability. Still will have probability of precipitation for rain showers/thunderstorms and rain
focusing on the morning...lower in the afternoon Thursday.

&&

Short term /Thursday night through Friday night/...
upper level trough will remain over the northeast through the
period although heights will rise by Friday as trough axis shifts
west of region. A more significant short wave will pass through the
area on Thursday. This feature will move through the area during
the morning and early afternoon hours. Increased probability of precipitation quickly
during the morning hours with likely probability of precipitation over the northern County Warning Area and chance
over the Wyoming Valley. Due to persistent cool pool aloft and
some instability will continue to mention thunderstorm. Thursday night
should be mainly clear behind departing wave and cool with lows
generally in the 50s.

Friday morning looks dry with surface high pressure along the East Coast
and southwest moderating flow. Later in the day another short wave
may lift north from the middle Atlantic region bring scattered
showers and thunderstorms late Friday through Friday night. Highs
on Friday will be near normal ranging from the upper 70s to lower
80s.

&&

Long term /Saturday through Tuesday/...
320 PM Tuesday update... the large-scale pattern of a western Continental U.S. Ridge and eastern
Continental U.S. Trough will persist through the period...although it should lose
some amplitude/retrograde a bit over the weekend.

As for the sensible weather...diurnally driven showers/thunderstorms are foreseen
each day...perhaps most numerous Friday and Sat afternoons...when a
coastal surface boundary backs slowly westward...and also early next week...when
a cold front approaches from the west. Chance/scattered probability of precipitation will be
employed for now...given the customary uncertainties at these time
ranges.

Temperatures should average close to seasonal norms for early Aug...with
highs from the upper 70s-middle 80s...and lows in the 50s-lower 60s.

&&

Aviation /18z Wednesday through Monday/...
expecting mainly VFR conditions with scattered-broken cumulus between 4500
and 6000 feet this afternoon under middle to hi clouds. Isld to scattered
thunderstorms and rain will form and could affect taf sites between 18z and 24z. I
didn/T put any thunder in the tafs because I believe it will be
isld. For now have tempo groups for MVFR rain showers. The rain showers will die
down after sunset and addtnl scattered VFR rain showers are possible around 12z.
It is possible that there could be some MVFR rain showers but coverage
looks to be sparse so didn/T put in terminals for now.

Thursday am...I see scattered-broken cumulus evolving again with scattered rain showers around
the terminals. But it should remain mainly VFR.

Outlook...

Thu-Mon...restrictions possible each afternoon...in isolated to
scattered showers or thunderstorms.

&&

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

&&

$$
Synopsis...djn
near term...djn
short term...rrm
long term...mlj
aviation...djn

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