-- Discussion containing changed information from previous version are highlighted. --
583
FXUS61 KBGM 051905
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
305 PM EDT Wed Jun 5 2024

.SYNOPSIS...
Another warm and humid day today with late afternoon scattered
showers and thunderstorms around. A period of steadier rain and
embedded thunderstorms moves through tonight into Thursday. An upper
level low then brings an unsettled, cooler and showery weather
pattern for Friday and the upcoming weekend.

&&

.NEAR TERM /THROUGH THURSDAY NIGHT/...
920 AM Update...

No major changes to the near term forecast; updated current and
near-term temperatures. Chances for rain showers and
thunderstorms increase from west-to-east across Central NY and
NE PA starting in the mid-afternoon.


645 AM Update

Starting off a little cooler than expected in the valley
locations, which dipped down into the 50s. Skies are clear from
Binghamton and Syracuse north and east...with scattered to
broken mid and higher level clouds back to the southwest across
NE PA and the Central Southern Tier of NY. CAMs continue to show
it remaining generally dry through mid-afternoon today, then
showers only very slowly expand from west to east heading into
the evening hours. Overall, no significant changes were needed
with the sunrise update.

420 AM Update

Main concerns in the near term will be the potential for
thunderstorms later this afternoon, tonight and again on Thursday.
Some of these storms could produce heavy downpours with an isolated
risk for excessive rainfall and perhaps some poor drainage flooding
issues. WPC has the area under a marginal risk for excessive
rainfall this evening and tonight...then the Catskills and Mohawk
Valley is still in a marginal risk on Thursday as well.

Today starts off quiet with mostly sunny skies this morning. Clouds
gradually increase from SW to NE through the day. Latest CAMs show a
few showers or t`storms developing by 3-5 PM over the western Finger
Lakes region. The rest of the forecast area is now trending drier
through the day. It will be another warm day, and more humid as dew
points rise well into the 60s. Daytime highs will range from the
upper 70s to mid-80s...except upper 80s to near 90 for the Syracuse
metro area and Mohawk Valley region.

A warm frontal boundary then approaches this evening, moving east-
northeast across PA and into the NY southern tier with showers and a
chance of thunderstorms. By this time MUCAPE is falling to just a
few hundred J/Kg at best, but PWATs are rising between 1.6 to 1.8
inches...which is  2 to 2.5 standard deviations above average for
early June. This will combine with warm cloud layer depths around
11k ft thick to bring the potential for very efficient, and locally
heavy rainfall. This moisture laden pattern persists overnight, with
most of the guidance showing the heaviest rain potential over NE PA,
the Catskills and perhaps into the NY southern tier region...further
north across CNY the CAMs are showing lighter rainfall amounts.
Otherwise, tonight will be warm and humid with lows in the 60s
areawide. Rainfall amounts could be locally over 1" where the
heaviest showers/storms develop.

By Thursday morning, this initial band of rain/storms will be moving
east, out of the CWA across the Catskills. There could be a brief
lull in the rainfall activity, before the main front swings through
mid morning to early afternoon from west it east. This will bring
another round of rain and t`storms to the region. PWATs remain
somewhat elevated as this front moves through; around 1.50 inches.
MUCAPE also builds out ahead of this boundary, perhaps between 500-
1000 J/kg east of I-81 by midday. This could initiate more convection
and thunderstorms which could in turn produce more locally heavy
downpours. Storm total rainfall will be highly variable over
the region, but generally between a 1/4 to 3/4 of an inch; except
higher (up to 2") in areas that see more thunderstorm activity.

After 2 PM Thursday, the latest guidance is in fairly good
agreement that winds will turn westerly, ushering a
progressively drier air mass. PWATs fall to between 0.75 to 1.1
inch and surface dew points slide back into the mid-50s to
lower 60s. This air mass will no longer be conducive to heavy
rain threats. However, still cannot rule out some isolated to
scattered pop up shower and a slight chance for a thunderstorms
in the afternoon and early evening hours. Skies will see partial
clearing, trending toward mostly sunny conditions late in the
day. This late day clearing and drying will allow daytime maxes
to still reach the mid-70s to lower 80s.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
-- Changed Discussion --
306 PM Update...

A complex blocking pattern across Canada and the North Atlantic will
result in broad troughing across the northeastern CONUS through
early next week. Embedded in that pattern, a closed mid-level low
will move slowly from Georgian Bay to the Ottawa Valley between
Friday morning and Saturday night. Several weaker shortwave troughs
will swing through our area like spokes on a wheel through the
period, modulating periods of showers and thunderstorms, with cooler
air aloft bringing below normal temperatures.

Timing of a shortwave trough on Friday looks to be fairly well-timed
with the diurnal cycle for fairly widespread showers and isolated
thunderstorms during the afternoon. Bulk shear values are
impressive, 50-60 knots, but instability looks to be weak, with the
typically hot-running NAM suggesting max CAPE values of 300-400
J/Kg.

Precip looks to die off quickly after dark as the shortwave trough
pushes east of the area and daytime heating abates.

Additional showers look to favor mainly areas north of the Twin
Tiers on Saturday as another shortwave trough rolls through early in
the day. Another more significant round of showers is possible
Saturday night as a stronger shortwave trough drops through the
area. Though uncertainty remains high, a narrow band of heavier
precipitation is possible with this disturbance.

High temps look to hang around the upper-60s to lower-70s Friday and
Saturday, roughly 5 degrees below seasonal normals.
-- End Changed Discussion --


&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
306 PM Update...

As the slow-moving upper low finally moves into the Saint Lawrence
Valley Sunday, a final shortwave trough looks to dig down into the
lower Great Lakes. This will bring widespread rain showers and
isolated thunderstorms across the region, along with continued
cooler than normal temperatures.

Cyclonic NW flow will persist into Monday, with additional mostly
diurnally-driven showers expected. A weak shortwave trough pushing
through may favor the late morning and early afternoon hours for
precip, with drier conditions moving in by evening. Temperatures
look to remain cooler than normal, with highs in the upper-60s to
lower-70s again.

Finally, a drier spell looks to set up beginning Tuesday.
-- End Changed Discussion --

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
120 PM Update...

VFR conditions are expected at all terminals for the next 6
hours. MVFR conditions and rain showers will move into each of
the terminals, west to east, this evening. Rainfall will
intensify overnight, leading to conditions falling from MVFR, to
fuel alt, and then to IFR by the end of the 06/08Z for all
terminals. These conditions will likely last through at least
12Z, but there`s uncertainity with exact timing of improving
conditions after 12Z, so we made the decision to leave all
terminals in IFR at the end of this TAF package.

Outlook...

Thursday... Scattered showers and thunderstorms around with
MVFR Fuel Alt and even IFR restrictions likely. Lifting back to
mainly VFR after around 18z Thursday afternoon.


Thursday night through Sunday...

Occasional showers with brief restrictions likely.

&&

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

&&

$$

SYNOPSIS...MJM
NEAR TERM...KL/MJM
SHORT TERM...MPH
LONG TERM...MPH
AVIATION...KL