273
FXUS61 KBGM 250808
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
408 AM EDT Sat May 25 2024

.SYNOPSIS...
A frontal boundary will bring scattered showers and thunderstorms
to the region this afternoon through this evening. This system
sweeps through quickly, as Sunday will be mostly dry before the
next system moves in late Sunday evening and into Monday.

&&

.NEAR TERM /THROUGH SUNDAY/...

4 AM Update...

High pressure is still in control this morning with dry
conditions across the area. Ridging flattens out later today and
low level southwesterly flow develops, which will start to
increase moisture this afternoon. Although dew point
temperatures this morning are generally in the mid to upper 40s,
this push of moisture will increase dew point temperatures into
the upper 50s to low 60s by late afternoon. Forecast soundings
show little CAPE at first with the very dry air in place,
however where the surface dew point temperatures increase and
theta-e advection is maximized (generally west of I81),
instability should be sufficient enough to support convection
with CAPE values increasing to 700 - 1200 J/kg out ahead of the
approaching shortwave this afternoon. How far eastward any
convection will survive will be dependent on the increase
moisture. Latest CAMs may be a little too bullish on how
eastward thunderstorms spread this afternoon, as forecast
sounding indicate too much dry air generally east of I81, which
may be tough to overcome. However, the HRRR shows a line of
storms pushing completely across our forecast area from this
afternoon through this evening. Definitely will have to do a
mesoanalysis later today to check on moisture advection, but for
now there is just too much uncertainty to say for sure that
storms will be able to hold together all the way from western
NY to the Hudson Valley.

SPC drew the eastern extent of the Marginal risk line for
severe thunderstorms almost directly over the I81 corridor. It
should be noted, that 0-6 km shear is only forecast to be 25 to
30 knots, but that may be enough to support some strong winds
approaching severe limits, especially if instability can exceed
1000 J/kg of CAPE.

All guidance agrees that this system will exit the region
overnight, leading to cool and quiet conditions late tonight/early
Sunday morning. With the added moisture from the showers and
storms as well as skies clearing out some, patchy fog/low
stratus may develop. Overnight lows will be in the mid 50s to
low 60s, but could be cooler where skies clear the most.

Sunday should remain mostly dry through the day, but another
shortwave arrives possibly as early as Sunday afternoon. This
will kick off another round of scattered showers and
thunderstorms in the vicinity of a stationary front that will
aligned west to east across northeast PA. At this time, the
Poconos Region to the Catskills will be most likely to see some
afternoon storms develop on Sunday.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
230 PM update...

The short term starts off quiet with mid and upper level ridging in
place keeping the region mostly dry and warm. A deepening area of
low pressure in the central US will be lifting a warm front into our
area later in the day with increasing clouds aloft. Precipitation
looks to hold off until Sunday night. Chances of showers and
thunderstorms increase through Sunday night as strong warm air
advection. Forecast soundings show some weak elevated instability
developing but with the lack of steep mid level lapse rates, storms
will stay on the weaker side and not too widespread.

Monday has a better chance for widespread showers and thunderstorms.
Much of NEPA and upstate NY will be in the warm sector of a low
moving through the Great Lakes into Canada with a cold front moving
through in the afternoon. 0-6 km shear is looking to be between 30
to 40 knots but CAPE is on the lower end with a grand ensemble mean
of just under 1000 J/kg with most ensemble members 500 J/kg and
lower. Forecast soundings are pretty saturated so clouds will limit
day time heating and with the lack of any steep lapse rates, CAPE
will be long and skinny. Severe threat looks pretty low as of now
with the marginal parameters but heavy rain and flash flooding may
be more of a concern. PWATs get over 1.5 inches but with some
directional shear in the low levels helps limit backbuilding of
storms but rainfall rates will be high with any storm. With little
capping in the warm sector and the cold front moves through late in
the day, several rounds of storms are looking possible so any
location that gets hit multiple rounds of storms have the best
chance at seeing any flash flood problems. Chances of rain dwindle
behind the front Monday night with drier and cooler air advecting
in.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
230 PM update...

The long term is looking cooler as a long wave trough slowly moves
in. Shortwaves embedded in the flow will still lead to unsettled
weather. Chances were added each afternoon even on quieter days as
the cold air aloft coupled with the strong solar heating plus
greenup will help destabilize the atmosphere in the afternoons. QPF
amounts are not very high in each shortwave this next week as there
is not too much moisture to work with being under the upper level
trough and most of the moisture shunted to the south but ensemble
means on days 3 to 7 do get over an inch for most of the area.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
Mostly VFR conditions expected through the period. There will be
a chance for late afternoon and evening showers/thunderstorms
across the NY terminals with the highest confidence in TS at
ITH, ELM, and BGM. After any showers or storms push through,
expecting VFR conditions with possible fog moving into ELM
towards the end of the forecast period at 6Z Sunday.

Outlook...

Saturday Night... Restrictions possible in fog, especially in
river valleys.

Sunday...Mainly VFR expected.

Monday through Wednesday... Restrictions possible with
scattered showers and thunderstorms, especially on Monday and
into Tuesday.

&&

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

&&

$$

SYNOPSIS...MPK
NEAR TERM...MPK
SHORT TERM...AJG
LONG TERM...AJG
AVIATION...MPK