989
FXUS61 KBGM 171940
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
340 PM EDT Tue Jun 17 2025

.SYNOPSIS...
Scattered showers are expected tonight ahead of an approaching
warm front, especially across Northeast PA. Warmer weather
arrives Wednesday into Thursday, providing more energy for
showers and thunderstorms especially in the afternoons. After
temperatures temporarily settle back Friday, they will surge
much warmer into early next week.

&&

.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
340 PM Update:

While cloudy, most of the day today has been dry with stable air
in place and the approaching warm front still well to the south
and west. This will change this evening as a batch of showers
across Central PA is approaching the area ahead of the
aforementioned warm front. The coverage of showers will be
highest across Northeast PA, but there still may be some
isolated showers this evening across parts of Central NY,
especially the Southern Tier. Thunder looks unlikely, but cannot
be totally ruled out across Northeast PA with some elevated
instability. Otherwise, tonight will remain cloudy with
temperatures remaining nearly steady in the 60s. Dewpoints will
be on the rise tonight with the warm front passage, so it will
become increasingly humid as well.

We will be in the warm sector on Wednesday following tonight`s
warm front passage. By the afternoon, there will likely be some
breaks of sun, which will allow for temperatures to rise into
the upper 70s to mid 80s. This is not incredibly warm for this
time of the year, but after cool and cloudy weather the last
several days, it will definitely be noticeable. Dewpoints will
rise to the upper 60s to near 70, so it will also be on the
humid side. A weak shortwave embedded within southwesterly flow
aloft will be enough to spark some scattered afternoon showers
and thunderstorms. Severe thunderstorms are not anticipated, but
with PWATs increasing to 1.6-1.9 inches, locally heavy rainfall
will be possible, especially towards the Wyoming Valley-Poconos-
Catskills.

With the loss of diurnal heating and the exiting of the
shortwave, mainly dry conditions are expected Wednesday night
besides a few possible lingering isolated showers. Lows are
expected to be in the mid 60s to near 70 degrees.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
200 PM Update...

The main concern continues to be the potential for severe
thunderstorms Thursday afternoon. SPC places our area in a
Marginal to Slight Risk of Severe Thunderstorms, with potential
somewhat favoring Northeast PA and areas along/east of I-81 in
NY versus points west.

Model guidance continues to have timing differences with the
frontal passage, with the GFS having a weaker low moving through
Ontario and a much more positively tilted upper trough over the
Great Lakes and NE. This slows the frontal passage, with the
better forcing moving through the area during peak heating. The
NAM and Euro have a stronger surface low moving through Ontario
with a more neutral upper level trough, allowing the strong
forcing from the front to move through quicker, with the front
passing through the Finger Lakes in the morning, and hitting the
I-81 corridor and east during peak heating. This scenario would
keep most of the severe storms east of I-81 while the GFS
scenario would put much more of the CWA under a better chance
for severe storms. The current forecast lies more with the
Euro/NAM solution, putting the I-81 corridor and eastward under
the best chances for severe storms. This lines up well with the
SPC forecast, putting this area under a Slight Risk.

With this timing, NBM guidance puts a 50-80 percent probability
for CAPE to reach above 1500 J/kg along and east of I-81. Bulk
shear values also look to be trending in the right direction for
severe weather development, with 40-50kts of 0-6km bulk shear
values across the aforementioned area. Damaging winds, hail and
even an isolated chance for a tornado will be possible with
these storms given the low level inverted V soundings, CAPE
pushing high PWAT values (1.5-1.8) into the hail growth zone,
and hodographs showing enough low level for there to be a chance
a spin up could occur in a strong updraft.

The high PWAT values also show a chance for isolated flash
flooding issues across the area. With the NAM/Euro solution,
storms are expected to be progressive, but there could also be
some training of storms over a portion of the area. Warm cloud
depths above 10k feet and cloud-layer flow at times nearly
negating the low level jet vector could lead to backbuilding
storms. This will be especially true if a more GFS-like
scenario wins out. Because of this, our area is in a Marginal
risk for excessive rainfall leading to flash flooding.

Temps on Thursday are forecast to reach the upper 70s to low 80s
in the Finger Lakes, with the rest of the region seeing low to
mid 80s. Temperatures ahead of the front will be dependent on
cloud cover, with current guidance having scattered clouds. If
we can get some more clearing, CAPE values will increase and
thus storm strength will increase as well.

We will be closely monitoring the evolution of this system.

After the frontal passage moves through the region by Thursday
night, temperatures will fall into a much nicer mid to upper 50s
with dewpoints in the mid 50s.

Friday will see the beginning of a very strong ridge building
into the region that will dominate the weather pattern through
at least the middle of next week. For Friday, temperatures will
be in the 70s to low 80s with a slight chance for an afternoon
pop up thunderstorm.

The high pressure continues to build in Saturday, with current
guidance putting us on the northern edge if the ridge. This
positioning will allow for a shortwave to dive into the area
from the Great Lakes along the edge of this ridge. This
shortwave could ingest the warm air under the ridge and the
higher shear values sitting north of the ridge. This would
generate a Mesoscale Convective System (MCS) that is currently
progged to move into the region Saturday evening and overnight.
Where this system impacts will will depend on how far north the
ridge builds, with some guidance pushing it across the northern
portion of the CWA, with other guidance keeping the ridge
farther south and allowing the MCS to move through most of the
CWA. Heavy rain, gusty winds and lighting would be the main
threats with this system. There is a Marginal Risk for
excessive rainfall causing flash flooding across much of the
CWA.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
310 PM Update...

The main focus for this period is the first real heat wave of
the season impacting the CWA.

The ridge building into the area this weekend into the early
part of next week will be anomalous high, approaching 500mb
heights close to 600dm. These high heights correlate to high
surface temperatures expected to build into the region starting
Sunday and lasting through Tuesday. Sunday should see highs in
the upper 80s to low 90s, increasing to low to mid 90s on
Monday. Tuesday could be a few degrees cooler, but highs will
still be in the low to mid 90s. These temperatures combined with
very high dewpoints (upper 60s to low 70) being advected in
from the Gulf will lead to heat indices in the mid to upper 90s
for much of the area Sunday through Tuesday. Valley locations
could see values above 100 for a few hours in the afternoon on
Monday.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
Mainly MVFR to Fuel Alternate ceilings are expected to remain
for the remainder of today. A round of light to moderate showers
may move through late this afternoon/early this evening, which
may bring brief IFR restrictions. Otherwise, IFR ceilings will
become more prevalent later tonight into early Wednesday
morning, before ceilings return to mainly MVFR by late Wednesday
morning/early afternoon.

Outlook...

Wednesday afternoon through Thursday...Coverage of showers and
thunderstorms increase, especially each afternoon. Occasional
restrictions likely.

Thursday night through Sunday...Mainly VFR, but isolated to
scattered afternoon showers and possibly a thunderstorm may
result in brief restrictions; chances somewhat better for NY
terminals versus KAVP which may stay dry.

&&

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

&&

$$

SYNOPSIS...BJG
NEAR TERM...BJG
SHORT TERM...JTC/MDP
LONG TERM...JTC
AVIATION...BJG