849
FXUS61 KBGM 220127
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
927 PM EDT Fri Jun 21 2024

.SYNOPSIS...
Hot and humid conditions with scattered thunderstorms continue
this evening and redevelop Saturday and Sunday. A few stronger
storms any of these days may produce damaging winds and
torrential rainfall. Heat and humidity will subside Monday.

&&

.NEAR TERM /THROUGH SATURDAY NIGHT/...

915 PM Update...

Updated PoPs and temperatures based on the latest observations.
Radar shows a cluster of thunderstorms still impacting mainly
the Wyoming Valley and Poconos region of NE PA at this time.
These storms have been producing isolated damaging winds and
torrential downpours earlier this evening. Updated fog coverage
for the overnight period as well, as some areas of fog do look
likely to develop. Otherwise, expect a warm and muggy night
with lows in the mid 60s to lower 70s. Saturday will be another
very warm and humid day with highs ranging from 85 to 95 over
the region. Heat advisories remain in effect for the Twin Tiers,
south across all of Northeast PA.

240 PM update...
Primary concerns in the near term are focused on the continued
threat for hazardous heat/humidity today and Saturday, along
with potentially severe thunderstorms the rest of this afternoon
and again Saturday afternoon.

Large dome of high pressure centered over the southern
Appalachian Mtns is expected to persist into this weekend with
hot and humid conditions reaching north into the mid Atlantic
and Northeast. Heat Advisories for the southern tier of NY and
northeast PA continue today and through the day Saturday.
Afternoon temperatures have climbed into the upper 80s and lower
90s today, with dew points in the upper 60s and lower 70s
making it feel like 90 to 100 from Syracuse-Utica south to
Scranton/W-B.

The heat and humidity today has led to a broad axis of
instability over southern NY and northern PA. Weak inhibition
earlier this morning led to rapid convective development with
little time for the storms to build up steam. The lack of
steering flow and a very limited amount of deep layer shear has
brought about unorganized storms and chaotic storm motions. The
robust amount of deep moisture allowed a few of the storms so
far to produce some wet microbursts, and this will continue to
be the main threat into the early evening hours. Many of these
storms have left behind outflow boundaries that other convection
may focus on today, so timing and location of additional
convection will be difficult to nail down.

The storms will subside after sunset this evening and
conditions will stabilize. Plenty of moisture in the boundary
layer and a weak near sfc inversion will allow for another round
of low clouds and fog tonight. Temperatures will only fall into
the upper 60s and 70s tonight.

The threat for heat/humidity ramps back up late Saturday
morning and continues into the afternoon...especially for the
southern tier of NY and ne PA. Temperatures back into the upper
80s near 90 for central NY and into the lower to mid 90s for ne
PA are expected with heat indices 90 to 100.

Another round of thunderstorms will develop Saturday
afternoon...similar to today within a similar type air
mass/environment. So we can expect the storms to be slow-moving
again with the threats being heavy rain, lightning and brief
strong, possibly severe, wind gusts. The timing on Saturday
looks to be around 1 PM to around 6 PM.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
The pattern is finally expected to shift Sunday as the strong upper-
level ridge responsible for the long duration heat and humidity
begins breaking down as a shortwave trough and surface cold front
approach from the west. This will lead to an increasing chance of
showers and thunderstorms Sunday, especially during the afternoon
and evening when precipitation appears likely. With the cold front
trending a little bit faster early this morning, moving into our
area during peak heating hours, along with 1000-1500 J/kg of surface-
based CAPE in place and 30-40 knots of shear, there will be the
potential for some stronger storms to develop. Mid-level lapse rates
are not very impressive at this point, so this looks to be more of a
wind threat with any potential stronger storms along with heavy
downpours with PWAT values in excess of 1.5 inches. The SPC has
outlooked the entire CWA in a marginal risk this day. With
uncertainty with the timing of the front, cloud cover and the
convection, temperatures on Sunday will be tricky to forecast. Highs
have trended down several degrees across CNY in the low and mid 80s
with the faster progression of the front, while the Twin Tiers into
NE PA range from the mid 80s to the low 90s. This still gets some
heat index values to around 95 for the Southern Tier of NY into NE
PA. So the heat advisory was extended through Sunday with the
afternoon forecast package.

As the front pushes east, the upper trough will lag behind over the
area on Monday, keeping the chance for scattered showers and
maybe a thunderstorm around. However, cooler, drier air will be
moving in for most areas as dew points fall back into the upper
50s and low 60s by the afternoon. Highs Monday are expected to
be from the mid 70s to the low 80s. With the Wyoming Valley
being one of the last spots for this more refreshing air to move
into, highs this day can still reach the mid and upper 80s. It
will feel more comfortable Monday night with lows in the upper
50s and low 60s.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Only subtle changes to the previous long term discussion. GFS
trended more toward the ECMWF suite with a cooler and more
progressive look later next week. High pressure briefly builds in
overhead Tuesday leading to a dry day before another front looks to
bring the chance for showers and storms back into the area Wednesday
into Thursday. With ridging aloft Tuesday, high temperatures are
expected to trend back into the 80s, but it`s not expected to feel
too humid as dew points remain in the upper 50s and low 60s, but
they will be trending up Wednesday ahead of the front. Wednesday is
expected to also expected to have highs in the 80s, and perhaps
nearing 90 degrees in a few places, before cooler air moves in again
for the second half of the week.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
LIFR, heavy thunderstorms will be impacting AVP over the next
hour or so (until 22/01z).

Conditions will stabilize after 00-01Z and areas of low clouds
and fog are expected to develop once again through the overnight
hours. The most favorable locations for fog are ELM, BGM and
AVP; where the heaviest rainfall occurred. ELM should see a
period of IFR or lower fog, mainly between 07-11z Saturday morning.

Conditions will return to VFR at most sites, after the fog
lifts and mixes out around 12-13Z, through the rest of the
period. There could be some MVFR cigs and light rain showers
that move in from the north just before between 12-16z and
impact RME and SYR.

There will also be more scattered showers and possible
thunderstorms around after 18z, but confidence on location and
timing was too low to include in the tafs at this time.

Outlook...

Saturday evening through Monday...Spotty restrictions possible
in showers and thunderstorms.

Tuesday and Wednesday...VFR conditions likely.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...Heat Advisory until 8 PM EDT Sunday for PAZ038>040-043-044-047-
     048-072.
NY...Heat Advisory until 8 PM EDT Sunday for NYZ022>025-055-056-062.
     Air Quality Alert until 11 PM EDT this evening for NYZ062.
     Air Quality Alert from 11 AM to 11 PM EDT Saturday for NYZ062.

&&

$$

SYNOPSIS...BJT
NEAR TERM...BJT/MJM
SHORT TERM...DK/MWG
LONG TERM...DK/MWG
AVIATION...BJT/MJM