Flash Flood Watch 10, NWS Binghamton, NY

Broome County, NY, Cayuga County, NY, Chemung County, NY, Chenango County, NY, Cortland County, NY, Delaware County, NY, Madison County, NY, Oneida County, NY, Onondaga County, NY, Otsego County, NY, Schuyler County, NY, Seneca County, NY, Steuben County, NY, Sullivan County, NY, Tioga County, NY, Tompkins County, NY, Yates County, NY, Bradford County, PA, Lackawanna County, PA, Luzerne County, PA, Pike County, PA, Susquehanna County, PA, Wayne County, PA, Wyoming County, PA

Area Forecast Discussion
National Weather Service Binghamton NY
213 AM EDT Sat Oct 28 2017

.SYNOPSIS...
High pressure will keep our weather mild and fair through
Saturday afternoon. A strong storm system will bring significant
rain into central New York and Pennsylvania Saturday night
through early Monday, with much cooler air expected for next
week.

&&

.NEAR TERM /THROUGH TODAY/...
850 PM update...little change to the near term at this time.
Temps are falling off quickly under clear skies this evening so
have adjusted the hourlies downward overnight, and lowered the
min a bit. Otherwise just some minor adjustments to the winds.
Previous discussion continues below.

330 PM update...High pressure continues to dominate our weather
this afternoon bringing fair weather. Other than some high
cloudiness moving through portions of the area, plenty of
sunshine will continue this afternoon with relatively mild
temperatures.

For tonight, high slips off to the east with a southerly flow
occurring over the area on its western side. As a result,
temperatures will be milder than this morning with lows in the
40s.

For Saturday, deep trough amplifies as it approaches the east
with southerly flow strengthening due to the gradient ahead of
approaching front to the west. The day should start out with
sunshine giving way to increasing clouds through the afternoon
as the front approaches. Expect conditions will be dry through
at least mid afternoon or so before the chance of showers
develops from west to east. Any heavier rain looks to hold off
though until after dark. Highs will be generally in the low to
mid 60s so fairly mild for late October.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
350 pm update... An active, wet period is still foreseen.

In the big picture, model agreement remains fairly good, in
showing the progression of a deep, negatively tilted upper
trough through the eastern states this period. In response, a
surface low rapidly intensifies by Sunday, as it moves up the
east coast and eventually into western New England or eastern
NY. Again, though, subtle but important differences show up
between individual model solutions with just how far westward
the main frontal-scale heavy rain band develops. The EC and
Canadian models now show the heaviest precipitation across our
western zones (the Finger Lakes region), while the NAM and GFS
are a bit farther east (generally from the I-81 corridor
eastward into the Catskills and Poconos). These small details
are not likely to be completely resolved until sometime over the
weekend, as the systems themselves begin to develop and
interact with one another. Another wild card will be development
of a potential tropical cyclone by tonight/early Saturday in
the Caribbean Sea/eastern Gulf of Mexico, and how this system
may interact with the strengthening, baroclinic upper trough
mentioned earlier.

Bottom line, confidence in heavy rainfall (broad 2-4", with
locally higher amounts) is fairly high for later this weekend
across CNY/NEPA, but exact amounts and positions are yet to be
worked out. Please stay tuned for the latest updates. We
continue to highlight associated hazards in our hazardous
weather outlook and also our web page (www.weather.gov/bgm).

Heavier rains should quickly lift out of the region from SW-NE
by Monday morning, with mainly dry conditions for the afternoon
hours.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
The weather pattern during the long term period shifts from a
mean eastern trough at the onset to southwesterly flow, with
the trough axis fluctuating between the Northern Plains and
Great Lakes.

The entire period is forecast to be unsettled for NY and PA,
with rain showers possible by day and a few wet snow showers
mixing in overnight in the normally colder locations.

The best chance for rain comes on Thursday when a cyclone moves
across the US-Canadian border and drags a cold front into NY.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions will prevail through Saturday evening as
southerly flow increases ahead of an approaching storm system.
LLWS is expected through early Saturday morning at KELM, KITH,
KSYR, and KRME. Winds will gust at 20 to 25 knots this
afternoon.

Rain will reach most our terminals between 2z and 6z Sunday
morning, with ceilings quickly falling to between 1200 and 2500
feet and visibilities fluctuating between 1SM and 6SM.

Outlook...

Sunday through Monday...Restrictions likely in rain as large
wet and windy system passes; then scattered showers into Monday.

Tuesday...Rain chances diminish but occasional restrictions are
still possible.

Wednesday...Next system, a weaker one, may arrive bringing a
chance of rain and associated restrictions.

&&

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

&&

SYNOPSIS...DGM/PCF
NEAR TERM...DGM/PCF
SHORT TERM...MLJ
LONG TERM...DJP
AVIATION...DJP

Hazardous Weather Outlook
National Weather Service Binghamton NY
415 PM EDT Fri Oct 27 2017

NYZ009-015>018-022>025-036-037-044>046-055>057-062-PAZ038>040-043-
044-047-048-072-282015-
Northern Oneida-Yates-Seneca-Southern Cayuga-Onondaga-Steuben-
Schuyler-Chemung-Tompkins-Madison-Southern Oneida-Cortland-Chenango-
Otsego-Tioga-Broome-Delaware-Sullivan-Bradford-Susquehanna-
Northern Wayne-Wyoming-Lackawanna-Luzerne-Pike-Southern Wayne-
415 PM EDT Fri Oct 27 2017

This Hazardous Weather Outlook is for central New York and
northeast Pennsylvania.

.DAY ONE...Tonight.

Hazardous weather is not expected at this time.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

A strong storm system will bring the potential for heavy rainfall
later this weekend, from Saturday night through Sunday night.
Rainfall of 2 to 4 inches is possible over much of the region, with
locally higher amounts possible. Rainfall of this magnitude could
cause localized flooding, if it falls within a short enough period
of time. Exact positions of the heaviest rainfall are still
uncertain, so stay tuned for future forecast updates.

As colder air wraps into the system late Sunday night into Monday,
northwest winds will become quite gusty. Sporadic power outages are
not out of the question, especially at higher elevations. It is also
possible that rain could briefly mix with wet snow, across some of
the higher elevations.

Please stay tuned to the National Weather Service, or local media
outlets, for the latest updates on this upcoming storm.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Jurewicz