-- Discussion containing changed information from previous version are highlighted. --
798
FXUS61 KBGM 191025
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
625 AM EDT Mon Aug 19 2024

.SYNOPSIS...
A frontal system will pass through today with another round of
showers and isolated thunderstorms. While Tuesday will be mostly dry
and cool, showers return by mid-week as a low pressure system is
slow to move out of the Northeast. Quieter and warmer conditions are
expected for the second half of the week.

&&

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

Rain is just now beginning to move into the the Finger Lakes
region. PoPs were increased in the northern portions of the
Finger Lakes for this earlier arrival. Otherwise, the forecast
is doing well and needed no additional changes.

345 AM Update...

A frontal system will bring showers to the region beginning early
this morning. This front will pass through the region today and exit
by this evening. Some isolated thunderstorms will also be possible,
especially east of I-81. Instability looks to be limited as MLCAPE
is only modeled to be around 500 to 750 J/kg. Shear values are also
low at around 20 lows. While SPC clips the region (Sullivan and Pike
Counties) with a Marginal Risk for severe storms, there is not much
that indicates that stronger storms will develop in our region
today. It is possible that daytime heating helps these areas become
more unstable than forecasted late today. WPC also has a Marginal
Risk for excessive rainfall for most areas east of I-81. Some of the
short-term guidance does have PWATs nearing 1.7 inches. Expected
rainfall amounts are low, but there is potential for localized
heavier showers. If a heavier shower were to pass over an area that
had flooding issues yesterday, then flash flooding could occur again.

Some showers will be possible overnight as a shortwave trough moves
through the region. These showers will be light and quick to move
through. Drier air moves into the region Tuesday, so conditions will
quiet down, but only briefly. An upper-low dips south as wraparound
moisture is advected in from the north. Spotty showers will develop
late in the day over portions of CNY.

High temperatures will be in the mid 60s to mid 70s today with a
large gradient from north to south. With the showers moving in,
those in CNY will likely reach their highs by midday while those
further south will have more time to warm up. Much cooler air will
fill in behind the front tonight as T850 drops into the single
digits.Forecasted lows will be in the upper 40s to low 50s.
Extensive cloud cover will help keep us from reaching record lows
though. Temperatures will only climb into the 60s Tuesday, though
the Wyoming Valley may exceed 70.
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&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
305 AM Update...
Chilly and unsettled conditions are anticipated midweek.

An anomalously deep and compact upper low will pivot across the
Northeast during midweek with much cooler-than-normal
temperatures as well as scattered showers, especially in Central
New York where lake enhancement will occur. You read that
correctly, a lake effect influence in August, which is quite
doable considering 850mb temperatures projected in the models as
low as 3-4 degrees Celsius versus water temperatures closer to
20 degrees Celsius. Ensemble data shows the return interval of
these chilly 850mb temperatures for this date, to be less than
one day per 10 years. While forecast temperatures are not at
record lows, since there will be cloud cover and mixing, they
will be within a few to several degrees of record low maximums
for Binghamton-Syracuse, and more like 8-9 degrees from record
low maximum for Scranton. To summarize, daytime temperatures
10-14 degrees below average will definitely feel like an
abruptly early taste of Fall.

Models project the upper low core dropping directly over the
area Wednesday, with temperatures starting off at morning lows
of only mid 40s to lower 50s. Cyclonic chilly flow around it
appears likely to bring a deeper lobe of moisture, helped by
lake enhancement as well, to yield plenty of clouds. Chances for
showers had to be adjusted significantly up into the high
chance to likely range, particularly for Central New York
Wednesday. Amounts will not be much, only a tenth to quarter of
an inch at most with majority less than a tenth of an inch. But
at least scattered showers will certainly be around for Central
NY into the Twin Tiers, and a few stretching even deeper into
Pennsylvania. Highs will be only in the 60s for most locations.

Wednesday night, instead of northwesterly flow with gusts of
10-20 mph like during the daytime, there will be backing of
lighter winds to westerly or even west-southwesterly. This will
diminish the lake influence to mainly along and north of the NY
Thruway, ending showers for most of the area as the upper low
also starts to head northeast of the area. While we will still
be within its outer periphery Thursday, after lows again of mid
40s-lower 50s, temperatures will moderate somewhat to highs of
upper 60s mid 70s. While Wednesday will have plenty of clouds,
more sunshine will be managed on Thursday.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
305 AM Update...
A fairly quiet period is foreseen as we head into next weekend,
with temperatures trending from around average to even slightly
above.

The departing upper low will finally open up and scoot out of
the Northeast, making way for an approaching ridge. A large heat
dome is projected over the Southern to Central Plains late this
week, with a warm and dry ridge riding over it across the Upper
Midwest-Western Great Lakes. This will eventually nudge its way
our direction, allowing temperatures to warm from 70s-near 80
Friday, to mostly lower-mid 80s by Sunday if not even some upper
80s in our lower elevations. Dewpoints will initially be
comfortable, but by Sunday may trend more into the 60s to add a
little humidity. We will have to see if any weak waves riding
through the top of the ridge, may harness the warmth and
humidity for a small chance of thunderstorms around late
Sunday-next Monday. For now though, dry conditions appear most
likely to prevail.

&&

.AVIATION /10Z MONDAY THROUGH FRIDAY/...
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Showers begin to move into the region this morning as a frontal
boundary dips south. With these showers, ceilings will fall
into IFR to LIFR categories. Visibilities will also be reduced.
Showers move out of the region this evening and ceilings will
begin to improve beginning around 00z. All terminals will be
MVFR to VFR early Tuesday morning.

Winds will become gusty as the front moves through.
Northwesterly winds will gust to around 15 to 20 kts. After 00z,
gusts subside, though sustained speeds will be 5 to 10 kts.

.Outlook...

Tuesday through Wednesday...Mainly VFR; lingering showers
possible, especially over the Central NY terminals.

Thursday through Friday...Mainly VFR with high pressure over the
region.
-- End Changed Discussion --

&&

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

&&

$$

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