-- Discussion containing changed information from previous version are highlighted. --
738
FXUS61 KBGM 261754
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
154 PM EDT Wed Jun 26 2024

.SYNOPSIS...
Partly sunny and warm through the early afternoon hours today.
Then, numerous showers and scattered strong to severe thunderstorms
will impact the area by late afternoon into this evening. Rain
showers continue overnight, before conditions dry out with
gradual clearing on Thursday. Expect seasonable temperatures
with dry and mostly sunny skies for Friday.

&&

.NEAR TERM /THROUGH THURSDAY NIGHT/...
1225 PM Update...

The cloud cover over CNY has kept dewpts in the 50s. Elsewhere,
dewpts have climbed into the 60s, which is mainly across the
Twin Tiers and NEPA. The current thinking is that the best
conditions for scattered strong to severe thunderstorms will be
across these areas with skies have been more sunny and dewpts
have climbed into the 60s. Temperatures are already into the mid
80s at some locations as well. Models have also showed that the
better conditions would likely be in the areas mentioned. With
these storms, there will be heavy rainfall. Flash flood guidance
across NEPA and the Catskills is high and that`s where models
are targeting with the higher rainfall as well. Concerns for
isolated hydro issues would increase if the higher rainfall were
to extend farther north as most of CNY counties are at least a
0.5 inch lower with FFG than areas south.

Onset timing has not changed much based on the latest CAMs. It
does look like the rain and storms will move out quicker
overnight than previous forecasted. PoPs were updated based on
the newer guidance, but some slight changes may be needed this
afternoon.

915 AM Update...

A layer of clouds has nudged into the Twin Tiers. This layer
extends all the way back into the Central Great Lakes region.
This layer of clouds will continue to spread eastward, so sky
cover was increased throughout the day. Temperatures are quickly
rising as Syracuse has already hit 80. Highs may need to be
increased, but were left alone for now as recent guidance kept
temps similar.

Early assessment of model guidance indicates no changes to what
was previously seen for the potential of severe weather today.
There still remains uncertainty with the instability gradient,
but the best conditions will be over the southern half of our
CWA. Of course, we will have to monitor how conditions evolve
throughout the day.

645 AM Update

No significant changes to the near term portion of the forecast
with this sunrise update. Latest visible satellite loop shows a
mix of clouds and sun out there early this morning, with
decreasing clouds expected through the morning and early
afternoon hours. Hourly temperatures were adjusted based on the
latest observations and trends. It is a very warm start out
there today for some locations; many areas are starting out in
the upper 60s to mid-70s as of 6 AM...but the cooler valleys
that decoupled are in the lower 60s. The timing and intensity of
the potential severe storms remains the same on the latest 06z
3km NAM and 09z HRRR runs. For what it is worth the HRRR
continues to show isolated very strong winds (50-65 kts) with
some of the storms early this evening...this is usually
overdone, but it is an interesting signal to see in the
guidance.

430 AM Update

A few isolated to scattered showers will be possible through
daybreak over northern portions of central NY. Otherwise, clouds
will scatter out with mostly sunny conditions later this morning
and into at least the early afternoon hours. It will be warm
with highs generally in the 80s to around 90.

The main concerns in the near term will be a Slight Risk for
scattered severe thunderstorms late this afternoon and evening
from the Twin Tiers and Catskills south across all of NE PA.
There is a Marginal Risk for an isolated severe storm further
north across the I-90 corridor and Mohawk Valley. The main
hazards with any severe storms today will be strong to damaging
winds and torrential downpours, so isolated instances of hail
are also possible. CAMS and model guidance continue to struggle
with the amount of low level moisture (i.e. sfc dew points)
later this afternoon and evening, and therefore the amount of
MLCAPE that will be present. Our CWA will have a tight
instability or CAPE gradient setting up; likely somewhere near
the Twin Tiers.

Based on some of the CAMs, such as the 00z and 06z 3km NAM it
appears that a differential moisture boundary sets up across the
Southern Tier this afternoon, with northerly winds advecting in
drier, more stable air into northern portions of Central NY.
The 00z 3km NAM indicates that for locations able to maintain
sfc dew points in the mid 60s to around 70, SBCAPE could reach
2000 J/Kg, with MLCAPE between 1000-2000 J/kg. The highest
amounts of instability will be in place over NE PA, with the
instability gradient setting up over the NY Southern Tier
region. 0-6km deep layer shear is forecast to reach 40-50 kts
over the area. LIs may reach -9 over NE PA along with mid level
lapse rates approaching 7.0C/Km. DCAPE over NE PA and the
Southern Tier of NY will range from 600-1000 J/Kg, which is
favorable for strong, isolated damaging winds to mix down to the
surface in or near thunderstorms. The last several runs of the
HRRR are showing the potential for thunderstorm wind gusts of 50
kts + with some the modeled storm cells; again mainly over the
Slight Risk area mentioned above.

The main timeframe to see these potentially severe
thunderstorms will be from around 5-7 PM in the Central Southern
Tier region, reaching I-81 corridor by 7-9 PM and the southern
Catskills between 8-10 PM. With PWATs up to 1.9 inches over NE
PA and 1.75 in CNY, locally heavy to excessive rainfall and
isolated flash- flooding could also occur with any training
thunderstorms. Further north across the I-90 corridor to Mohawk
valley the limiting factor for severe weather and flash
flooding will be the low atmospheric instability; but still a
marginal risk and worth monitoring trends through the day. After
the strong to severe storms pass by to the east by around 11 PM
this evening an area of stratiform rainfall will linger for
several hours. Areal average rainfall amounts are forecast to
range from 0.5 to 1.0 inch; but certainly higher amounts are
likely where the heavier and more persistent thunderstorms
develop.

Winds turn west-northwest later tonight and a good deal of cloud
cover lingers. Can`t rule out some patchy fog, but confidence
was low due to the increasing wind speeds up to around 10 mph
before daybreak Thursday. Seasonable overnight lows in the upper
50s to low 60s expected.

Clouds linger Thursday morning under the upper level trough in
the moist, cooler NW flow. Eventually drier air mixes out the
clouds, giving way to mostly sunny skies Thursday afternoon.
There will be a northwest breeze between 10-20 mph. Temperatures
will be cooler, but with the afternoon sun it still manages to
reach into the 70s areawide; with low 80s in the Wyoming Valley.
Overall, much quieter weather expected on Thursday.

&&

.SHORT TERM /FRIDAY/...

-- Changed Discussion --
1750 PM Update...

Capped the short term period at Friday as high pressure will
still be overhead during the day, but pushes east Friday night.

Previous Discussion...

Quiet weather on Friday with high pressure centered over our
region. Mostly sunny skies are expected with temperatures
climbing into the upper 70s to low 80s. Clouds will begin to
move in Friday evening as the next system approaches. Lows will
return to normal with temperatures ranging in the upper 50s to
mid 60s.
-- End Changed Discussion --

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...

-- Changed Discussion --
1750 PM Update...

High pressure pushes east out into the Atlantic Friday night and
deep SW return flow will bring moisture advection into the
region on Saturday. Models have remained consistent with the 12Z
cycle with PWATs progged to increase to 2"+, which is close to 3
standard deviations above normal for this time of year.
Showers and embedded thunderstorms with torrential downpours
will be likely with localized flash flooding possible. At this
time, the severe thunderstorm potential appears low for Saturday
afternoon, as ongoing rainfall and clouds over the area should
limit instability. High pressure will build back into the region
the start of next week with cooler and dry conditions expected.


Previous discussion...

Low pressure system tracks east and into our region on Saturday
along with a warm front producing showers and thunderstorms. Deep SW
return flow advects warm air and moisture into our region with PWAT
values 2-3 standard deviations above normal. Model soundings also
show a deep warm cloud layer up to 13K feet suggesting heavy
downpours and localized flash flooding is possible. Cold front from
this system will push through on Sunday with more showers and
thunderstorms. Model guidance shows an additional wave dipping
into our region on Monday, which could increase pops, but
decided to stick with the NBM this far out. Otherwise upper
level ridge moves into the region on Tuesday with drier
conditions returning. Another system approaches our area by
Wednesday with more possible showers.

Temperatures during this period fluctuate with highs mostly ranging
in the mid 70s to upper 80s and lows in the 60s. Temperatures
will be slightly cooler on Monday behind the cold front with
highs in the low to mid 70s and lows in the 50s.
-- End Changed Discussion --

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR conditions will continue until 21 to 00z. Rain showers and
embedded thunderstorms will move into the region late this
afternoon. Strong thunderstorms will be possible at ELM, BGM,
and AVP where strong wind gusts will be the main threat. Tempos
were added for thunderstorms at these terminals for the best
guess on timing, but additional adjustments may be needed as
conditions evolve. There is less confidence for thunderstorms
farther north. Visibilities and ceilings will fall as showers
spread across the region. While there is some guidance hinting
at IFR, conditions were capped at Fuel Alt for now. After the
showers move out, patchy fog may be possible. While it cannot be
ruled out at SYR and AVP, confidence was lower at those
terminals. Heading into the late morning hours, some lingering
MVFR ceilings will be possible as skies scatter out and improve
to VFR.

Winds become calmer overnight and direction will be variable at
times. Winds pick back up by midday Thursday with gusts around
15 kts.

Outlook...


Friday...Mainly VFR.

Saturday through Sunday...Restrictions from showers and
thunderstorms possible.

Monday...Mainly VFR.

&&

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

&&

$$

SYNOPSIS...MJM
NEAR TERM...BTL/MJM
SHORT TERM...ES/MPK
LONG TERM...ES/MPK
AVIATION...BTL