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000
FXUS61 KBGM 280537
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
137 AM EDT Wed Sep 28 2016

.SYNOPSIS...
Dense river valley fog is likely overnight and will burn off
Wednesday morning. Clouds will thicken Wednesday with showers
possible by Wednesday evening. Showery weather will last from
late Wednesday into the weekend.

&&

.NEAR TERM /THROUGH TODAY/...
730 PM update...Forecast on track. Only made minor changes to sky,
temp, dew point grids for this evening based on latest conditions.


2 pm Update...

A nice afternoon across our area with our region in a dry slot.
Even a CU field is having trouble forming with the most cloud
cover over northern NY (CU) or lake effect clouds north to
northeast of Lakes Erie and Ontario. We will remain mostly clear
overnight. With warm river waters, a light rainfall last night,
and calm conditions, river valley fog is likely to be dense
between 06Z and 13Z Wednesday. After early fog Wednesday sunshine
early will lead to thickening clouds especially southern NY and PA
ahead of our next system. Most of the rain will hold off but
showers are possible from the NY/PA border toward 5 PM as an upper
level low drops due south, and moisture around it increase in a
increasing southerly flow.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
230 pm update...Main focus this period will be on rainfall
potential with the slow moving closed upper low.

In the big picture, model agreement is excellent this period, with
a cutoff low in the upper levels meandering over the Ohio Valley,
and a large ridge axis extending from the western Atlantic across
eastern New England and southeastern Canada. This configuration of
systems will place central NY/northeastern PA in a deep, moist
east-southeast flow pattern. In and of itself, this should be
enough for plenty of clouds, along with periodic, mostly light
rainfall. The primary issue, though, is how much potential do we
have for something heavier/more significant. More details on this below.

The best combination of anomalous winds in the 2-5 thousand foot
layer and an associated surge of higher precipitable water values
(approaching 1.5"), along with forced lift from favorable upper
jet dynamics, appears to come from the pre-dawn hours Thursday,
through the day, and into the evening. It is then that locally
heavy showers could bring rainfall amounts of 1-2" from parts of
NY`s central southern tier down into portions of northeastern PA.
Given our dry antecedent conditions, such rainfall amounts would
be easily handled. However, with some potential for embedded
convection Thursday afternoon/early evening, any training cells
could bring locally higher amounts and some risk for poor drainage
area/urban type runoff issues. As a result, we will insert this
wording within our hazardous weather outlook.

Although showery weather should remain in place through Friday,
the overall character of the rainfall should become less
concentrated/more scattered with time, as a dry slot aloft appears
likely to approach the region from the south.

Temperatures will probably not move much this period, with daytime
highs mainly in the 60s, and clouds holding overnight lows in the
50s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
245 pm update...Although it should slowly open up/lift out to the
northeast with time, the above mentioned upper low/trough should
continue to have enough influence through the weekend, for at
least isolated-scattered showers. By early next week, it looks
like a short-wave ridge aloft will be moving in from the west,
with generally rain-free weather.

Given an apparent lack of any cool air push from central/eastern
Canada, temperatures should average near to above normal for early
October (highs from the mid 60s-lower 70s and lows in the 40s-
50s).

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
Valley fog will impact the KELM terminal this morning with
conditions expected to deteriorate into the IFR category between
08Z-10Z then near airport minimums until 13Z. Rest of period VFR
conditions are expected with mid clouds spreading across the
terminals this afternoon through early evening. Late in the TAF
period conditions at KELM/KAVP may drop into the MVFR category as
a southerly flow of increasing moisture develops.

Light and variable winds overnight becoming E/SE at 8-12 knots
this morning and continuing this evening.

OUTLOOK...

Wednesday Night-Sunday...Possible occasional restrictions from
showers associated with upper level system in region.

&&

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

&&

$$
SYNOPSIS...Heden
NEAR TERM...Heden/PCF
SHORT TERM...MLJ
LONG TERM...MLJ
AVIATION...RRM