544
FXUS61 KBGM 051850
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
250 PM EDT Fri Jul 5 2024

.SYNOPSIS...
Another warm and muggy afternoon expected with isolated to
scattered showers and thunderstorms. A weak front moves through
tonight helping to move some of the moisture out of the region
with Saturday looking drier especially later in the day. Hot and
muggy weather returns next week with frequent chances of
showers and thunderstorms.

&&

.NEAR TERM /THROUGH SATURDAY NIGHT/...
1015 AM Update...

Increased cloud cover across the area for the rest of the
morning and into the early afternoon hours based on the latest
GOES East Visible imagery and 12z HRRR. Guidance shows drier air
mixing in and clouds finally breaking some by about 2-4 PM; but
it will still be partly cloudy at best. An area of rain is
moving across the Twin Tiers and western Catskills at this time.
CAMs show thus area of light to moderate rain slowly translating
east into the early afternoon, with perhaps a slight uptick in
convective activity surrounding it. MLCAPE is low, just 100-200
J/Kg due to all the cloud cover and lack of surface heating thus
far. This will beginning to increase toward 500-1000 J/Kg by
late afternoon and evening as daytime heating increases low
level lapse rates. The other story for today are the very high
dew points in the low to mid-70s out there. This will certainly
make it feel much hotter than the actual temperature. By late
afternoon the heat index looks to peak around 90 for the valley
locations in CNY, but up to 92-99 in the Wyoming Valley.

Updated PoPs to better match the latest 12z HRRR for this
evening and overnight. It appears there maybe two rounds of rain
and t`storms. Number 1 in the evening hours from about 6-10 PM,
moving across CNY then round two after midnight into the early
hours of Saturday morning.

630 am update...
Overall little change to the forecast. Adjusted chances of
precipitation to match radar for the next couple of hours.
Chances of rain were lowered slightly overnight as the 500 mb
shortwave is a bit weaker but there is still plenty of
instability.

315 AM Update...

Cloudy skies overnight has helped keep temperatures warmer with
most of the region still in the 70s early this morning. A
cluster of showers and thunderstorms have developed in central
PA and will be moving into NEPA and the Southern Tier around mid
to late morning. Temperatures for the late morning through the
afternoon were lowered as there will likely be a cold pool left
behind by the rain in the morning. Dew points were once again a
little high with the NBM so some of the NBM 10th as well as the
Canadian Reg were blended in to drop dew points from the mid 70s
to low 70s.

There is still a lot of uncertainty in the precipitation
chances through the day as the morning rain will stabilize
things but most forecast soundings do have CAPE recovering by
the mid to late afternoon. Precipitation chances were kept
through the afternoon despite CAMs not showing much. Soundings
show a bit of CIN but it would not be too hard to be a degree or
2 warmer or terrain helps get a couple storms going and outflow
from those get other storms going in the afternoon across CNY
and the Southern Tier.

Tonight, a surface trough moves through that helps spark off a
round of more widespread showers and thunderstorms. It is
possible for a few of these thunderstorms to become severe as
bulk shear is up over 40 knots in forecast soundings and lifted
indexes getting below -5 along with elevated CAPE staying
between 700 and 1400 J/kg through the night. Hail and wind would
be the primary threats with the stronger storms.

With the surface trough moving east of the region Saturday as
well as no discernible 500 mb shortwave, there will not be
anything to trigger storms. Dew points also fall a bit in the
afternoon as some drier air advects in aloft and mixes down with
day time heating. Precipitation chances were reduced and
largely kept at a chance or higher in the Catskills down into
the Poconos.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
250 PM update...
Main concerns in the short term are focused on the typical
summertime hot and humid conditions Sunday and Monday with a few
weak thunderstorms kicking off Monday afternoon.

Weak/broad upper level ridge with gradual rising heights aloft
will lead to widespread suppression over the region Sunday and
Sun night with quiet weather. Precipitation chances are less
than 5% for the entire forecast area of central NY and northeast
PA. Temperatures on Sunday are expected to remain in the mid to
upper 80s in NY and into the upper 80s and lower 90s in ne PA.
Humidity values should be mostly tolerable with dew points in
the lower to mid 60s.

Another night of mild temperatures Sun night/Mon morning with
lows bottoming out in the 60s.

On Monday, a stronger push of the hot and humid air mass from
the south will occur which will allow high temperatures to rise
into the upper 80s and lower 90s for much of the region. Dew
points in the mid to upper 60s will make it feel just slightly
hotter, but still rather uncomfortable. The increased amount of
moisture and instability advecting into the region should lead
to slightly higher chances (10 to 15%) of thunderstorms by the
afternoon. Coverage of any storm that does form should be
isolated, the duration should be brief and the intensity should
be weak.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
250 PM update...
Low chances (10 to 20%) of showers and storms continue Monday
night as the upper short wave to the west gradually moves
eastward into a moist and unstable air mass. The overall forcing
during the night should be weak enough to keep storm intensity
to a minimum.

As Tuesday wears on the boundary layer will heat up once again
and dew points will climb into the lower 70s, which will make it
feel like the lower 90s. Much of the region will be under the
influence of the approach upper wave to the west, amidst the
deep moisture, which will induce widespread showers and storms
(40-60% chance) later in the day Tuesday into Tue night.

There is still quite a bit of uncertainty with respect to how
far east the trough axis/short wave will move. If the boundary
hangs back to the west, then a greater area of showers and
storms will be possible (30-45% chance) through the day
Wednesday. If the system is more progressive then chances will
be 10-25% lower, especially over the western Finger Lakes.

It appears milder air will move in late Wed into Thu with highs
only into the lower 80s along with lower humidity. However,
cannot rule out a few scattered showers and storms pretty much
any day later next week.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
2 PM Update

Scattered to bkn CIGs between 2500 to 8000 ft agl are lingering
over the region early this afternoon. These should lift to
mainly VFR cloud bases and scatter out more heading into the
late afternoon.

There will be a chance for scattered rain showers and isolated
thunderstorms between about 00z to 03Z, especially for the ELM
and ITH area...but it could also clip SYR, BGM or even RME. This
is round number 1. After a brief break, latest CAMs guidance,
including the HRRR show another more substantial round of rain
moving through between about 06-12z overnight into early
Saturday morning. There could also be embedded thunderstorms
during this timeframe as well. The highest instability looks to
be over the BGM and AVP area during the overnight hours, so
included PROB30 groups for TSRA here. Otherwise, with the clouds
and periods of rain not expecting widespread fog, but areas of
patchy fog are certainly possible even across the higher
elevation taf sites.

The rain showers should exit the area after daybreak Saturday
morning, but MVFR CIGs may linger through mid morning. Becoming
VFR by midday Saturday, but there will still be isolated
thunderstorm around, especially north of BGM, including the
ITH-SYR-RME area into the afternoon.

Outlook...

Saturday afternoon & Saturday Night...Isolated thunderstorms,
then areas of fog overnight with associated restrictions.

Sunday and Monday...Mainly VFR.

Tuesday and Wednesday...Showers and thunderstorms possible,
with associated restrictions.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...Air Quality Alert until 11 PM EDT this evening for NYZ062.

&&

$$

SYNOPSIS...AJG
NEAR TERM...AJG/MJM
SHORT TERM...BJT
LONG TERM...BJT
AVIATION...AJG/MJM