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FXUS61 KBGM 171836
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
236 PM EDT Tue Jul 17 2018

.SYNOPSIS...
A cold front will move through the area this afternoon and
evening, bringing an end to the showers and thunderstorms, and
relief from the heat and humidity. High pressure behind the
front will keep dry weather in the area Wednesday into Saturday.

&&

.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
2 pm update...

A surface cold front is pushing southeast through the CWA this
afternoon. A weak broken line of showers is along it.
Instability and shear is marginal. The airmass ahead of it has
been worked over with a large area of showers which had
thunderstorms leading it. Most of this has pushed southeast out
of the area. Not much happened with it. Clouds remain between
the convection so additional heating will be capped to around
80 degrees.

Behind the front low and mid clouds are isolated. Dewpoints are
dropping from around 70 into the 50s. This evening the front
will move southeast of the area leaving a much less humid and
cooler airmass for the rest of the near term. Temperatures will
fall into the mid and upper 50s. Mainly clear skies will move in
the rest of the this afternoon and evening, then continue
through Wednesday night. Cold and dry advection will be the rule
tonight and Wednesday with a northwest low level flow and an
upper level trough. Wednesday highs will be mostly in the 70s
which is slightly below average. Wednesday night will be even
cooler with lows in the lower 50s and upper 40s.

Valley fog will be patchy late tonight due to decent mixing and
dry advection. Wednesday night will have more fog with much
lighter winds. Most of the river valley fog will be over south
central NY and NEPA. High pressure will be centered over the
Great Lakes.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
Highly amplified upper flow makes for slow moving systems in
the short term, rather unusual for mid July. Omega style upper
ridge drifts slowly east from the Great Lakes with surface high
pressure just ahead over NY and PA. This will bring dry weather
with slightly below normal temperatures into Friday. After the
old system moves out this evening, forecast has very little
chance for rain through the period.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
400 AM Update

Not much change to the extended period. Still looking mainly dry
Friday and Saturday, with slightly above normal temperatures.
Then, turning wet and unsettled with showers and t'storms likely
Sunday, Monday and into next Tuesday as a slow moving upper
level low moves into the Northeast from the Ohio Valley. With
the clouds, showers and t'storms around temperatures will hold
in the mid-70s to lower 80s with increasing humidity. Updated
the forecast to reflect the latest trends in the available
guidance.

Previous Discussion Below...
Friday through Saturday:
Our region is on the backside of the high pressure which means
once again a warm and moist flow will advect into the region
with humidity and temperatures slowly on the increase. Highs
Friday will be back into the mid to upper 80's. Bumped the high
temperatures upward a bit on Friday given 925 mb temperatures
modeled around 21-23C. Overall, the pattern continues to slow
slightly leading to a higher probability of dry weather through
Saturday but some high clouds should be increasing during the
day. Could see an isolated shower or two across the far western
portion of the forecast area late on Saturday. High temperatures
remain in the 80s for most locations.

Saturday night through Monday:
The overall synoptic pattern is one that can produce several
rounds of showers and storms with a heavy rain threat. At 500
mb, a low pressure system will slow and attempt to dig and
cutoff across the Ohio Valley with ridging off the east coast.
This would result in a very aggressive stream of moisture from
the Gulf of Mexico and Atlantic coming northeast into the
region. The ECMWF and CMC runs and a fair cluster of ensemble
members from those models actually have this trough become
neutral to negatively tilted by Sunday which would raise the
possibility for development of a coastal low in addition to the
upper level low over the Ohio Valley. Another question is if the
low forming along the coast will have any tropical
characteristics. Right now model tracks of any coastal low are
generally up the Mid-Atlantic coast in the Sunday and Monday
timeframe with several members showing a left turn into our
region as the ECMWF 12Z 7/16. Still a lot of model runs to sort
the details for next weekend. Clouds and rain should knock highs
down closer to 80 with muggy lows in the 60's each day. This
forecast undercut the blended guidance by a couple of degrees
each day with the highs.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
130 pm update...

Showers have ended at the NY taf sites but will continue off and
on at AVP. The cold front is pushing through the NY sites ending
the IFR/MVFR cigs at BGM/ITH in the next hour. All NY sites will
be VFR after that and into Wednesday as skies clear.

AVP will have 2 hours of IFR due to cig and maybe vsby due to
steadier rain. The rain will end by 20z then a shower is
possible 21 to 23z. Brief restrictions are possible then.
Tonight and Wednesday VFR with clear to partly cloudy skies.

Valley fog should be patchy at most late tonight. Boundary
level winds are over 20 kts with dry advection occurring. Not
confident enough to include at this time.

West to northwest winds at 5 to 10 kts this afternoon becoming
light or light and variable tonight. Wednesday northwest to
north winds at 8 to 10 kts.

Outlook...

Wednesday afternoon through Saturday...Mainly VFR. Restrictions
possible due to valley fog each morning, especially at ELM.

Late Saturday through Sunday...Restrictions in showers and
thunderstorms.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.

&&

$$
SYNOPSIS...TAC
NEAR TERM...TAC
SHORT TERM...DGM
LONG TERM...MJM/MWG
AVIATION...TAC
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