898
FXUS61 KBGM 021055
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
655 AM EDT Tue Sep 2 2025

.SYNOPSIS...
High pressure will allow generally dry and pleasant weather to
persist through at least Thursday morning. A cold front is
expected to move through Thursday afternoon and evening, with a
batch of rain and a chance of thunderstorms. After another
showery frontal system early next weekend, cooler dry weather
will follow.

&&

.DISCUSSION...
Main forecast issue centers around a frontal passage Thursday
afternoon through evening, with a healthy batch of rain and
chance of thunderstorms.

High pressure remains in charge at the surface to keep
conditions generally dry today. Meanwhile, a weak upper level
low will wobble its way north out of our region, taking away
the high cirrus clouds with it. The atmospheric column
features gaping layers of dry air, so attempted cumulus tufts
midday through afternoon will have a tough time doing anything
more than a sprinkle. Indeed dewpoints are anticipated to only
be upper 40s-lower 50s, versus temperatures hitting 70s-near 80.
The chance for measurable rain is not zero today but in the
single digits percent range/sub-mentionable in the forecast.

For Wednesday, we start to get into return flow at the surface,
between the departing high and approaching frontal system that
will be in the Western Great Lakes, as a compact upper low
spins in the Upper Midwest. With plenty of sunshine as well,
most locations will tack on another 1-2 degrees.

The upper low is projected to shift into northwestern Ontario
Thursday-Thursday night, stacking up a with a surface low. A
negatively-tilted wave will press up into our region, with a
slowing cold front trailing from the distant low. With
southerly winds prevailing and strong moisture advection ahead
of the front there will be some Convective Available Potential
Energy (CAPE) on the order of 200-500 J/kg as temperatures reach
mid 70s-lower 80s. Shear will be decent with 0-6 km around
30-40 kts. For severe potential, model soundings are showing
tall and skinny CAPE and thus the missing ingredient is midlevel
lapse rates; not that impressive. Indeed the change in the air
mass pre-frontal to post- frontal is not dramatic; models have
been trending weaker with the front which more-or- less
dissolves, saving the bigger cold air advection push for the
second half of the weekend. Still, there could be a few stronger
gusts if convective cells/mini-lines are actually able to
generate.

There is a small yet mention-worthy concern for excessive
rainfall potential with this system. Precipitable water values
are up to 1.5. The National Blend of Models paints about 30-50
percent chance of more than an inch of rain across much of the
area with this system, and 10-25 percent chance of more than 1.5
inches. It has been rather dry lately so rivers will not be a
problem at all. However, Weather Prediction Center has been
advertising a Marginal Risk for Excessive Rain which is
reasonable; that means 5-14 percent chance of flash flooding
within 25 miles of a point. Poor drainage/urban areas will still
be susceptible if sustained higher rainfall rates occur. The
front itself will be slowing down, with deep nearly
unidirectional flow capable of backbuilding or training.
Embedded thunder of course could lead to locally higher amounts.

Late Thursday night into Friday, after the first cold front
moves through, the flow remains southwesterly. Highs will only
be down about 2-4 degrees Friday. Vorticity lobes pinwheeling
around the stacked low in James Bay will eventually send a
stronger front through the area during the first half of the
weekend with additional showers and a chance of thunder. Behind
that, generally dry yet more decidedly cool weather is
anticipated with highs of 60s-near 70 forecast Sunday-Monday and
lows falling to at least 40s.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
Mainly VFR conditions are expected through the next 24 hours (at
least through 12Z Wednesday). The one exception will be at KELM
early this morning as fog will result in IFR-or-worse visby
restrictions. Once fog dissipates after 13Z or so, VFR
conditions are expected to return at KELM before valley fog is
possible once again late tonight/early Wednesday morning.

Outlook...

Wednesday through Thursday morning...Mainly VFR.

Thursday afternoon through Thursday night...Restrictions
possible with showers and thunderstorms moving into the region.

Friday...Lingering showers possible, with associated occasional
restrictions.

Saturday...Scattered showers may bring occasional restrictions.

&&

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

&&

$$

SYNOPSIS...MDP
DISCUSSION...MDP
AVIATION...BJG