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504
FXUS61 KBGM 260431
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
1231 AM EDT Sun May 26 2024

.SYNOPSIS...
-- Changed Discussion --
Some areas of fog overnight into early Sunday, mainly in the
valley locations. The rest of Sunday will be generally dry,
other than a few brief pop up showers in Northeast Pennsylvania
and the Catskills. Our next system moves in late Sunday Night
into Monday with rain and a chance of thunder. Additional
scattered showers will linger through midweek.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
1000 PM Update...

Updates pops as showers are pushing out of northeast PA.
Otherwise some clearing starts to move in over our western
counties with patchy fog starting to settle in. Also made
changes to update temperatures and dew points using a blend of
current observations.

735 PM Update...

The thunderstorm activity has rapidly weakened and mostly ended
this evening as instability quickly wanes. Latest meso analysis
shows increasing surface based CIN over the region, with minimal
(<250 J/Kg) of SBCAPE and MLCAPE to still tap into. Over the
last half an hour, just about all the lightning strikes have
come to an end, with just a line of showers slowly progressing
along and east of I-81 at this time. Any severe threat is
certainly over at this time in our CWA. For the rest of tonight
there will be just a few scattered showers and perhaps an
isolated thunderstorm after midnight as some elevated CAPE moves
back into the Finger Lakes and NY Thruway corridor. Otherwise,
there will be some patchy fog around, as temperatures have already
fallen closer to the rising dew point readings this evening.
Overnight lows dip down into the mid-50s to lower 60s.

After some lingering morning clouds and patchy fog, it will turn
mostly sunny for our Sunday. There could be some pop up,
isolated thunderstorms over the Catskills and Poconos during the
afternoon and early evening hours. Otherwise, it will be warm
and slightly humid with highs in the upper 70s to mid-80s.

245 PM Update...
Thunderstorms, some gusty, will accompany a cold front through
the region this afternoon-evening, followed by mostly quiet
weather before moisture starts to creep back in late Sunday
night.

Thunderstorms have sprouted in Western NY-PA, where roughly
700-1200 J/kg Convective Available Potential Energy has
developed due both to diurnal heating and axis of moisture
pooled along the front. Farther east there is more dry air, but
models due indicate that the instability axis will still press
east-southeast across our area for the rest of this afternoon-
evening. Coverage of thunder will reduce as it gets east of I-81
but will not go away completely.

Model soundings show steep low level lapse rates, with
inverted-V appearance through at least 5000-6000 feet above
ground. One of those deals where any thunderstorms or even
shower cores should easily mix down gusty winds. Despite shear
being somewhat limited, this favorable boundary layer for mixing
down of winds supports the marginal risk for severe
thunderstorms from the Storm Prediction Center, for counties
along and west of I-81 as well as Chenango-Madison-Oneida
counties. The gusts may have a harder time, as with lightning
itself, as the storms head east of I-81 into this evening.
Confidence is high that showers-storms will be gusty, with
35-50 mph gusts to be common along the frontal line. The only
question is whether a few of the strongest storm cores manage
damaging gusts to 60 mph.

Cold front will be shallow, with moisture trapped under post-
frontal inversion late tonight-early Sunday. Thus low clouds and fog
are probable, with lows of mid 50s-lower 60s and additional
moisture from prior rainfall.

Sunday should remain mostly dry through the day, yet the
amorphous stalled front in Wyoming Valley-Poconos to Catskills
may be enough for a few pop up showers and isolated thunder
during the afternoon. The rest of the area though will be mostly
sunny with a lot of dry air mixing down from above the boundary
layer. Highs will be in the mid 70s to mid 80s. Clouds do start
to increasing Sunday night, however, as we get into return flow
ahead of our next system. Rain chances will start to bump up
towards dawn Monday, especially Twin Tiers southward as a warm
front moving into the region.

&&

.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
230 PM Update...
A warm front will lift north of the area Monday morning, with
southerly flow expected to advect in deeper moisture. Surface
dewpoints look to reach into the mid to upper-60s and PW values
1.6 to 1.7 inches. Rain showers will likely be on-going in the
morning, lifting northward towards the afternoon. Meanwhile, a
cold front and associated upper level disturbance will push in
from the west late in the afternoon or early in the evening,
bringing another round of showers and thunderstorms. These will
benefit more from the deeper moisture, and locally heavy
rainfall will be possible. One upside is that the system does
look fairly progressive, which could limit precip totals to some
degree. Localized flooding potential will be highly dependent
on antecedent conditions resulting from rainfall today and
Sunday.

Cyclonic flow will continue on Tuesday, with more widely scattered,
and lighter rain showers possible, along with somewhat cooler
temperatures.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
230 PM update...
A persistent upper level trough over Ontario and Quebec will
dominate the longer range pattern, with several shortwave troughs
expected to roll along its southern periphery into the northeastern
CONUS through the period. Cooler and showery conditions look to
persist Wednesday and Thursday, with drier and warmer
conditions working in late in the week, perhaps even well timed
with the weekend for a change.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
The threat for any thunderstorms has ended at our TAF sites.

Cold front passes through this evening into the overnight, with
shallow moisture trapped to cause lowering ceilings and areas
of fog. The steadiest rainfall occurred at SYR, RME, ELM and
ITH...with AVP getting some additional rainfall now. The areas
that saw higher rainfall totals will have high levels of shallow
moisture. This may get some low clouds and fog started by late
evening or the overnight hours as some partial clearing works
into the region.

The NY terminals will get into at least MVFR fuel alternate
levels below 2000 feet after 05-08z, and even likely IFR for
KBGM-KELM-KITH-KSYR for the few hours either side of daybreak
Sunday morning. Highest probability for fog is at ELM and ITH,
with lower probabilities for light fog/mist at RME, SYR and
BGM.

Improvement occurs by late morning to midday Sunday back to
VFR under weak high pressure, as ceilings scatter out and lift.
Isolated thunderstorms look to stay away from our TAF sites
Sunday afternoon/evening at this time.

Outlook...

Sunday evening...Mainly VFR.

Monday through Wednesday...Occasional restrictions likely from
multiple batches of showers and thunderstorms.

Thursday...Mainly VFR.

&&

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

&&

$$

SYNOPSIS...DK/MDP
NEAR TERM...ES/MJM/MDP
SHORT TERM...MPH
LONG TERM...MPH
AVIATION...MJM/MDP