619
FXUS61 KBGM 101731
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
131 PM EDT Wed Jul 10 2024

.SYNOPSIS...
The remnants of Beryl will impact the region today bringing
potential flash flooding and severe thunderstorms. A few showers
will linger into Thursday, before high pressure builds back in
for the end of the week.

&&

.NEAR TERM /THROUGH THURSDAY NIGHT/...
***Heightened risk for tornadoes and flash flooding today***

1145 AM update...
A Heat Advisory has been issued for more of central NY,
including the Finger Lakes and the western Mohawk Valley.
Temperatures are hot...into the upper 80s and lower 90s, and the
combination of dew points in the mid 70s has allowed heat
indices to climb into the upper 90 to around 100 range. It
should continue to heat up before the thunderstorms move through
later today.

943 AM update...
Conditions continue to come together today for a potentially
significant severe weather outbreak across a good portion of
central NY and possibly into northeast PA. At this time visible
satellite imagery is showing a thin layer of mid/high clouds
moving to the east over central NY with an expanding pocket of
clearing over western NY. This clear slot is expected to shift
east which will help destabilize the area. However, this will
likely also lead to some destructive cumulus clouds. Either way,
the end result will likely be a well mixed, very unstable air
mass south of the warm front...which is roughly along the I-90
corridor. There is still some uncertainty with respect to how
much, if any, convection develops within the warm sector prior
to the passage of the cold front later today.

The two areas of concern are along or just south of the warm
front, near the triple point, basically from the northern Finger
Lakes east through the western Mohawk Valley, and secondly along
an eastward progressing cold front that will sweep through
central NY and northeast PA. There are no changes to the overall
convective outlook and expected storm mode, with discrete
storms/supercells initially along the warm front, and then some
evolution into more linear-type storms later in the day as the
cold front sweeps through. Tornadoes and damaging winds are the
main threats.

We are still also slightly concerned about the threat of heavy
rain leading to localized flash flooding, especially over areas
to the north where multiple waves of convection are possible.

Previous discussion...
Hot and humid airmass will be in place over the area today as a
warm front pushes northward across the area this morning. Rain
showers and isolated thunderstorms are expected to form along
the front as it pushes north. CAM trends are showing areas west
of I-81 having the best chance to see rain showers with the warm
frontal passage this morning.

As the day progresses, the bulk of the forecast area will be
well entrenched within the warm sector. Strong instability will
build this afternoon with multiple models showing 2000-3000
j/kg of CAPE. The wind field also looks very primed for
supercell development in the afternoon hours with 0-6km bulk
shear values over 40kts that veer with height and nicely curved
hodographs through the afternoon hours. This, combined with a
very humid airmass that will keep LCL heights low, will allow
for a good chance for some discrete supercells to develop that
will be likely to produce a few tornadoes. SPC has increased our
area to an enhanced risk with a 10% probability for tornadoes
within 25 miles from a point across Central NY.

As the afternoon progresses, the remnants of Beryl will move to
the NE into Ontario. Several models are showing a second low
forming along the south shore of Lake Ontario, moving to the NE
during the late afternoon hours. This low is modeled to push a
cold front through the area during the evening and into the
overnight hours. Thunderstorms are expected to develop along
this front as it taps into the tropical airmass over the region.
Severe chances will remain into the early overnight hours as
the front moves through.

The tropical airmass we will see move into the area is very rare
for our region. PWATs are expected to surge into the 2.0 - 2.5in.
This is about 3 standard deviations higher than normal. A flood
watch for flash flooding has been issued for our northern CWA
from noon until midnight tonight.

Finally, a heat advisory also is in effect for all of NEPA and
Chemung, Tioga and Broome counties for tomorrow from 12pm to
8pm. The tropical airmass will push dewpoints into the low to
mid 70s in the valleys and combined with temps in the upper 80s
to low 90s, heat indices will climb into the mid 90s to low
100s.

The front will push east of the CWA after 2am Thursday morning
with some lingering showers remaining into the morning. Temps
will be in the mid 60s with dewpoints in the low to mid 60s.

Thursday will be cooler with highs in the lower to mid 80s.
There will also remain a chance for showers through the day
with troughing overhead.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
1130 AM update...

A weak slow-moving surface boundary will be hung up along the
East Coast Fri and Sat and allow for a persistent threat of
showers and storms. The most favorable chance for precip will be
over the Catskills and Poconos. A ridge of high pressure will
set up farther to the west and keep areas west of I-81 mostly
dry and quiet. Temperatures will remain hot with highs in the
80s and lower 90s. Humidity will remain elevated but not
extreme...with dew points in the 60s.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
1130 AM update...

The weak ridge over the interior NE Saturday night will slowly
trend to the east through the rest of the weekend. This will
bring a brief period of dry/quiet weather to the region Sat
night and Sun. There could be a few popup thunderstorms Sunday
afternoon/evening, but better chances for convection exist
Monday and Tuesday as the ridge breaks down and the synoptic
pattern becomes more cyclonic. Precipitation chances will be
elevated during the late afternoon/evening hours during peak
heating.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
A tropical, unstable airmass will be over the region today and
ceilings are expected to fall later today to near MVFR.

Thunderstorms have begun to develop across Central NY, and will
continue to develop and possibly impact the majority of
terminals through this evening. Due to the expected scattered
nature of these storms, we included a tempo group for all
terminals for a few hours into the TAF period, until a more
organized line of storms is expected to form and more west to
east around 21-23Z. Storms are expected to taper down mainly
after 00Z, with a few straggling showers through 02-03Z, and
there`s a possibility of fog to develop early in the morning,
with categories dropping down to MVFR/fuel alt to possibly IFR
visibilities. The highest confidence for possible IFR
visibilities to occur will be in ITH and ELM, but other Central
NY counties have small possibilities, but left out of the TAF
for now due to low confidence.


Outlook...
Thursday...Isolated showers possible, with associated
restrictions.

Friday through Monday...Mostly VFR conditions with isolated
showers possible.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...Heat Advisory until 8 PM EDT this evening for PAZ038>040-043-
     044-047-048-072.
NY...Flood Watch until midnight EDT tonight for NYZ009-018-036-037.
     Heat Advisory until 8 PM EDT this evening for NYZ015>018-
     022>025-036-037-044-045-055-056-062.

&&

$$

SYNOPSIS...MPK
NEAR TERM...BJT/MPK
SHORT TERM...BJT
LONG TERM...BJT
AVIATION...KL/MPK