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629
FXUS61 KBGM 180127
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
927 PM EDT Mon Jun 17 2024

.SYNOPSIS...
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Hot and humid conditions expected through the week, with the
worst conditions arriving tomorrow and persisting with little
relief through the rest of the week.
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&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
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920 PM Update...
Thunderstorm activity has diminished over the CWA as daytime
heating has subsided and an outflow boundary surged ahead of the
MCS, undercutting the instability that was present. Showers are
expected to stick around over the Twin Tiers for the next
couple of hours before dissipating. The forecast remains on
track with very hot and humid conditions for the rest of the
week.


625 PM Update...

As expected, thunderstorms have developed across the Finger
Lakes and western Southern Tier. Storms are expected to continue
to develop over this region, moving to the SSE through the
evening hours. Gusty winds are the main threat with these
storms, especially along the leading edge of the storms as DCAPE
here is 800-1000j/kg. CAPE values are high, around 1500j/kg
ahead of the storms up to the Broome/Cortland/Susquehanna county
lines. East of here, CAPE drops down to below 1000j/kg. CAMs
show storms dissipating as they approach this area, but given
their current structure and motion, confidence in this occurring
is low.


300 PM Forecast...
Prior to the onset of extended heat and increasing humidity this
week, parts of the region (mainly the Finger Lakes and Central
Southern Tier) will be impacted by some isolated to scattered
convection from compact upper level disturbance (MCV) currently
located over Western New York and the Niagara Frontier.

This feature will drift east late this afternoon and evening,
helping to increase initiate isolated to scattered late
afternoon and early evening showers and thunderstorms across the
Finger Lakes Region and Southern Tier of New York, with little
or no precipitation further to the east.

SPC placed approximately the western 40 percent of the CWA in a
MRGL risk for severe later this afternoon into this evening as a
result of this remnant convective disturbance and the increase
in MU CAPE to between 1500-2000 j/kg based on the latest HREF
and NAM guidance. Best potential for any storms to push SVR
criteria will be across the Central Southern Tier and Western
Finger Lakes over the next several hours where ML (0-1 KM) EHI
values reach around 1.5 M2/S2 late this afternoon and this
evening.

Otherwise...an upper-level ridge continues to slowly build over
the the region. Temps on track to reach forecast highs in the
upper 80s to low 90s. Temperatures will continue to rise into
Tuesday, up to the low to mid 90s, with heat indices of 95 to
100. A Heat Advisory will be in effect Noon Tuesday for portions
of Central NY and NE PA, and will last through Thursday
evening. With overnight temperatures not dipping much past 70
degrees, there won`t be much relief from the hot and humid
conditions.

A warm and rather muggy night is in store for the region with
variable amounts of mainly mid level clouds and a light
southerly wind. Low temps will range from the mid 60s across the
Western Catskills and Northern Poconos to the upper 60s and Low
70s across much of the Finger Lakes.
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&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
One of the challenges for this forecast will be chances for
thunderstorms from another one or two perturbations riding on
top of the ridge. Although heights will rise another few DAM on
Tuesday, the mid level cap probably won`t be strong enough to
negate select areas of terrain-induced/lake breeze boundary
convection from occurring.

Currently, there are only a few guidance solutions that depict
thunderstorm initiation for Tuesday late afternoon into the
evening, so there is a possibility for storms for Central NY,
mainly west of I-81. We`ll keep monitoring near-term guidance
for changes in solutions and chances for storm initiation
Tuesday.

Heat dome remains overhead through the period. Overnight lows
will struggle to dip below 70 most places. High pressure will
dip a bit further south on Wednesday and this will allow flow to
become more out of the west-northwest and increase potential
for isolated thunderstorm activity Wednesday afternoon into
Wednesday night as our area will fall a bit closer to the
periphery of the high pressure system. Instability will likely
peak above 2000 J/kg during the daytime hours, and although
there will be some CIN, models are indicating potential for weak
perturbations within the flow that could be enough to break the
cap. The heat will still be an issue Wednesday with heat index
values near 100 or even above in urban areas. However,
thunderstorms may provide some brief relief where they occur.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
The heat will continue into the extended period. Thursday will
be another hot day with most of the area approaching or
exceeding a 100F heat index once again. Thursday could end up
being the hottest day of the week, but this will be dependent on
afternoon convection.

Guidance suggests that 500mb heights could finally begin to
fall Friday into the upcoming weekend, which should lead to a
(subtle) cooling trend. However, heat indices could still
approach or exceed 100F across the southern potion of the CWA
Friday afternoon. Even into Sat and Sun, heat indices in the
valleys of southern NY and NE PA could still top out in the low
to mid 90s.

The falling heights will be accompanied by a slightly better chc
for daily convection Friday through the weekend, which would
also produce at least a bit of relief from the heat.

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
A line of showers and thunderstorms are currently pushing
through the Twin Tiers. ELM is the only terminal seeing
restrictions as heavy rain is bouncing vsby in and out of IFR.
This should occur for another hour or so before the rain
dissipates. The forecast challenge for these TAFs is if fog
will occur at ELM during the overnight hours. Heavy rain soaked
the ground for a couple hours, dropping dewpoint depressions
down to 1-2 degrees. Winds are strong now, moving WNW at 8mph,
but if we can get the winds to go calm later this evening, we
should be able to see fog development. Cirrus blow off from the
storms across PA and NY will hinder cooling tonight which will
also impact fog formation. Given we are missing some needed
ingredients for fog formation, my confidence was not high
enough to include IFR in this set of TAFs. Hopefully we will be
able to get a better picture of the situation in a few hours and
be able to lock it down in the next TAFs.

All our other terminals are expected to be VFR through the
period with high pressure overhead. There may be some more
afternoon showers and thunderstorms tomorrow, but confidence
that these will impact a terminal was way too low to include in
the TAFs.


Outlook...

Monday Night...Mainly VFR.

Tuesday through Friday...Spotty restrictions possible in
showers and thunderstorms, with probabilities increasing slowly
in the later part of the period.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...Heat Advisory from noon Tuesday to 8 PM EDT Thursday for
     PAZ038>040-043-044-047-048-072.
NY...Heat Advisory from noon Tuesday to 8 PM EDT Thursday for
     NYZ009-015-018-022>025-036-037-044>046-055>057-062.
     Heat Advisory until 8 PM EDT Thursday for NYZ016-017.

&&

$$

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