975
FXUS61 KBGM 201018
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
618 AM EDT Sat Jul 20 2024

.SYNOPSIS...
Scattered showers and thunderstorms will be possible this afternoon
and tonight, mainly across Northeastern PA and Catskills. A weak
front will bring isolated showers and storms to Central NY Sunday.
More widespread showers return by midweek. Temperatures trend
slightly warmer through early next week.

&&

.NEAR TERM /THROUGH SUNDAY/...
615 AM Update...

Fog has developed in the valleys and visibilities have been
reduced. As usual, fog should clear out over the next couple of
hours. Overall, the forecast is doing well though some minor
adjustments were made to the hourly temps based on the latest
observations. It does look like conditions will be favorable for
fog in the river valleys again tonight and not just limited to
areas that will see showers today. Because of this, patchy fog
was added in the river valleys.

305 AM Update...

Scattered high clouds continue to spread northward. Within the
breaks, fog is beginning to develop in the valleys of the Catskills
as seen on satellite. Similarly to yesterday morning, fog is
expected to spread in the valleys before lifting later this morning.
Today will start out dry, but a series of shortwaves just south of
the region will bring showers to the southern half of our CWA.
Isolated showers will be possible across NEPA and Catskills this
morning, but chances increase by the afternoon. Showers may drift
north into the Southern Tier as well. Models are showing about 500
J/kg of MLCAPE and 25 to 30 kts of shear. This will be enough to
support isolated to scattered thunderstorms, though severe weather
is not expected. Heading into the overnight hours, the environment
becomes more stable and thunderstorms will transition to just rain
showers.

These showers should be fairly light, though a brief downpour will
certainly be possible under thunderstorms. Forecasted QPF has
localized amounts up to a half inch. The latest NAM seems to be an
outlier as it has over an 1.5 inches of rainfall for some locations
across the Twin Tiers due to training of showers/storms. Other model
guidance is far from that extreme. Given dry conditions the last
couple of days hydro issues are not expected.

Showers will work their way out of the region early Sunday morning.
In areas that receive showers today/tonight, patchy fog may develop
thanks to the added moisture and light winds. Sunday will start out
dry but a weak front drops south from Canada into CNY, bringing
isolated showers and afternoon thunderstorms with it.

Temperatures today will max out in the upper 70s to mid 80s and then
fall into the upper 50s to mid 60s tonight. Temperatures will trend
slightly warmer Sunday as most will observe 80s though a few
locations may just hang onto the 70s.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
325 AM Update...

The weak front dissipates over the region Sunday night. The
center of a 1020mb surface high will move overhead, bringing
calm winds to the valleys which should allow fog to develop.
Overnight lows will fall into the mid 50s to low 60s.

Monday will see warmer temperatures as winds shift to more SSW
and advect in a warmer air mass. Highs are expected to climb
into the low to mid-80s with humidity gradually increasing. A
weak shortwave will move into the area as the ridge to the south
weakens and slides eastward. This, combined with increased
moisture from SSW flow will allow for a chance of rain showers
and isolated thunderstorms to develop during the afternoon and
especially evening hours. The best chance (30-40%) for precipitation
will be over NEPA and into the Southern Tier of NY in our CWA.

Rain chances continue through Monday night as another shortwave
and weak surface low moves across the region from the Mid-
Atlantic and moisture continues to advect into the area. Lows
fall into the mid 60s with dewpoints increasing into the mid 60s
to upper 60s as the night progresses, so it will feel quite muggy.

The broad cyclonic, southwest flow associated with the trough
over the central Great Lakes and enhanced by the offshore ridge
continues Tuesday and Tuesday night. Subtle shortwaves will
continue moving through the region in the moisture rich
southwesterly flow regime. PWATs rise between 1.6 to 2.0 inches
during this timeframe along with MUCAPE of 1000-2000 J/kg during
the afternoon and evening hours. This mean scattered to numerous
showers and thunderstorms rolling through the area. Storms could
produce locally heavy rainfall and WPC does have our entire
forecast area outlined in a Marginal Risk for Excessive
Rainfall and isolated flash flooding. A few storms could also
turn strong with gusty winds as deep layer shear is running
25-35 kts in the 0-6km layer. Nudged PoPs down a touch from the
widespread categorical the NBM was advertising; but still
showing high end likely to low end categorical in the move
favored locations...based on the latest guidance. Otherwise,
Tuesday will be partly sunny and humid with highs in the low to
mid-80s and overnight lows in the mid to upper 60s again.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
340 AM Update...

The deep southwesterly, cyclonic flow continues over our area on
Wednesday. The upper level trough begins to sharpen over the
Central Great Lakes. Some of the latest 00z guidance is starting
to show slightly lower available moisture and instability on
Wednesday as the main forcing remains back to our west. With
this in mind, again decided to nudge PoPs down from the
widespread categorical the NBM was advertising, back to high
end likely. The 00z GFS is hinting at a prefrontal trough during
the afternoon, with dew points and PWATs falling markedly
behind this boundary. Overall, it is looking like another day of
scattered to numerous showers and t`storms around, but perhaps
not much in the way of a forcing feature, as the 00z ECMWF
actually shows subtly rising 500mb heights over the area. Deep
layer, 0-6km shear likely remains between 25-45 kts and at least
the southeastern half of the CWA is under a Marginal Risk for
Excessive Rainfall from WPC. Otherwise, Wednesday will feature
mostly cloudy skies, humid conditions with highs in the upper
70s to low 80s. Thursday is starting to become more interesting,
as some of the 00z deterministic guidance is showing the main
upper level trough approaching and broad upper level divergence
over the region. This would provide better lift, with continued
steady levels of wind shear, moisture and instability present.
Maintained likely PoPs for showers and t`storms on
Thursday...and again this will be a day to monitor as we get
closer in time for possible severe threat and/or heavy rainfall.
Steady temperatures and dew points continue, under mostly
cloudy skies.

By Friday, guidance is starting to show drier air working into
the region as the upper level trough/low will either be on top
of us or already off to the north/east...depending on the model
and exact timing. PoPs were lowered to lower end chance or
slight chance for mainly a few lingering rain showers.
Otherwise, it will turn mostly to partly sunny with highs in the
low to mid-80s and slightly lower humidity. Next weekend is
looking mainly dry, with a warming trend as an upper level ridge
builds overhead.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions are expected throughout this TAF period for most
terminals. Scattered showers and thunderstorms are expected to
develop this afternoon and continue into the overnight hours.
AVP has the best chance to see showers, but timing remains
uncertain due to the scattered nature of the expected showers.
Because of this, VCSH remains in the TAF at AVP. Models show a
band of showers developing near the NY/PA border, so it`s
possible that BGM could also see a shower later today.

Similar to this morning, fog will develop after 06z in the
valleys. Confidence is highest at ELM, where visibilities may
fall into the IFR category. If the Wyoming Valley were to get
some showers, then conditions may become favorable for fog at
AVP as well. Throughout this TAF period, winds will be light.


Outlook...

Sunday through Monday...Mainly VFR; fog possible Monday morning.

Tuesday and Wednesday...Showers and thunderstorms with
associated restrictions. Best chance of rain in the late
afternoon, evening and early overnight hours.

&&

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

&&

$$

SYNOPSIS...BTL
NEAR TERM...BTL
SHORT TERM...MJM
LONG TERM...MJM
AVIATION...BTL