Area forecast discussion 
National Weather Service Binghamton New York 
326 am EDT Tuesday may 21 2013 


Synopsis... 
a warm and humid weather pattern has set up across the area and 
will continue through Thursday, with high temperatures near to 
just above 80 and lows mainly in the 60s. Scattered showers and 
thunderstorms can be expected,. A cold front will track across the 
area Thursday night with showers and thunderstorms. Much cooler 
weather will follow behind the front Friday and Saturday. 


&& 


Near term /until 6 PM this evening/... 
320 am update... 
warm front located across northern zones at this time. Weak WV is responsible for 
sparking off convection, mainly north of the New York thruway however a 
few pin-prick storms are developing further to the south. 


Warm front will leaving County Warning Area in warm sector for a time this afternoon with dewpoints 
climbing into the 60s and maximum temperatures in the 80s area-wide with valley 
locales into the mid-80s. This will lead to instability increasing 
through the day, though how much remains to be seen. 00z NAM indicates convective available potential energy 
on the order of 2000-3000 j/kg while 00z GFS showing around 2000 
j/kg. This will be plenty of instability to generate tstms, however 
trigger will be lacking until closer to 00z when WV rounds the upper level 
trough. 


Latest models showing warm front sinking back through the area which would 
likely provide a trigger for afternoon convection. In addition, ongoing 
convection along with wind shift may lay out boundaries drg the day today. 
Have kept chance probability of precipitation through a good portion of the day with scattered rain showers/thunderstorms and rain 
expected and after 21z as WV gets closer, have increased probability of precipitation to likely 
across northern zones. 


Potential exists for a strong to an isolated severe storm this afternoon with 
anything that is able to form. Expecting mostly pulse thunderstorms today with 
meager wind fields. 


&& 


Short term /6 PM this evening through Thursday night/... 
320 am update... 
WV will ride up along the front tonight along with shortwave topping the 
ridge. Have continued likely probability of precipitation across northern zones through 06z tonight with a 
gradual decrease after this time. Convective available potential energy remain elevated leading to 
thunder continuing. 


Shower and thunderstorm chances will continue until frontal passage late Thursday night. Uptick 
in activity drg the afternoon hours and have bumped probability of precipitation to likely during each 
day. Potential continues to exist for strong to severe storms tomorrow and 
Thursday. 


Frontal passage occurs by midnight Thursday night. Likely probability of precipitation are expected just along 
and ahead of the front then taper off to chance after 06z Friday. 


&& 


Long term /Friday through Monday/... 
medium range models continue to show a deep upper level trough over 
the northeast through most of the period with heights gradually 
building late as this trough lifts east. This will keep temperatures 
5-10 degrees below normal with min temperatures cold enough for possible 
frost both Friday/Saturday nights and maybe even Sunday night. 


At the sfc, Post cold front showers/thunderstorms will linger 
through the overnight period with best chance for thunder during the 
early evening. As the upper level trough builds in on Friday the chance 
for showers will continue with the highest probability of precipitation in the southern 
Catskills and NE PA. Remainder of period will be dry with partly 
to mainly clear conditions as surface high pressure from central Canada 
drops south across the Great Lakes region to our vicinity by Monday. 


&& 


Aviation /08z Tuesday through Saturday/... 
06z update... 
low confidence forecast during the taf period in regards to 
placement of thunderstorms...but outside of any thunderstorms 
mainly VFR overall. Initial line of storms carrying through ksyr 
just before taf time with gusty west-northwest wind shift from earlier storms 
immediately behind...en Route for krme. In wake of those 
storms...fairly quiet initially today with light and variable wind 
overnight becoming west-southwest at 5-10 knots. Weak wave will 
carry through the area this afternoon with heating of unstable 
atmosphere sprouting some thunderstorms. Exact timing and 
placement uncertain but prob30 groups assigned to the best 
potential times for each taf site accordingly. Additional storms 
will be possible with a stronger wave 02z-06z Wednesday but 
confidence not yet high enough to include in taf. 


Outlook... 


Late Wednesday night/Thu...MVFR possible in showers/thunderstorms. 


Fri/Sat...VFR. 


&& 


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


&& 


$$ 
Synopsis...pvn 
near term...pvn 
short term...pvn 
long term...rrm 
aviation...mdp