000
FXUS61 KBGM 021933
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
333 PM EDT Tue Jun 2 2020

.SYNOPSIS...
Severe thunderstorms possible late tonight and again tomorrow
across the Twin Tiers as a couple fast moving disturbance cross
the region. Weak high pressure builds back in on Thursday with
mainly dry weather, but another front may pass Friday.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
     Severe storms possible late tonight and tomorrow...

320 PM Update...

Confidence is growing for severe thunderstorms to impact the
region late tonight and again tomorrow. 12Z guidance is now in
good agreement with timing of shortwave arriving late tonight
around 3Z in Western NY and exiting region by 8Z or 9Z tomorrow
morning. Forecast sounding across the Southern Tier of NY and in
NE PA, show a low level stable layer, but strong elevated
instability exists above this shallow stable layer. RAP
soundings highlighting elevated CAPE values over 1000 J/kg (NAM
is likely overdone with over 2000 J/kg) and steep mid level
lapse rates in the 700 - 500mb layer near 8C/km.

Warm air/moisture advection surges in near the 850mb level with
an approaching warm front this evening. Storms late tonight
should ride along this boundary as short wave dives SE out of
Ontario. Strong 0-6km bulk shear of 50 to 55 knots with winds
veering from SE in the low levels to NW`rly aloft support
rotating storm updrafts and possibly a few right moving
supercells overnight. With strong shear and impressive mid level
lapse rates, but stable low levels, storms will be elevated, so
thinking is that large hail will be most likely severe risk
tonight. However, depending on the strength of the low level
inversion in place, can`t rule out at least a possibility for some
damaging wind gusts. For now, have mentioned the possibility of
at least some small hail in the forecast with gusty winds, and
if confidence continues to grow later this evening, then more
enhanced wording can be added to the forecast. Again, the
greatest chance to see any severe storms late tonight will be
from the Southern Tier of NY into NE PA.

After a brief lull in the action from the storms overnight, we
will see more storms enter the region from the west around mid
to late tomorrow morning as a cold front approaches. The best
threat for severe storms tomorrow looks to be from the NY/PA
border on southward. Because of the timing, uncertainty still
exists on the amount of instability, as there will likely be
little time to destabilize before storms move into our western
counties, with the greatest destabilization likely to occur
across our NE PA counties. Strong to severe storms will exit the
area early tomorrow afternoon, but can`t rule some lingering
showers into tomorrow evening.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
330 PM UPDATE...

Not much change to the short term with this mornings guidance.
The front is trending a little further south so PoPs were
adjusted as well as temperatures increased as clouds may try
and clear, especially for our northern zones.

Previous Discussion...
Cold front stalls over southern PA and becomes the focal point
for showers and thunderstorms in the period, but mainly south of
the area. Some showers and storms are possible Wednesday
evening as an upper wave and the front trigger convection, but
they should taper off after midnight. Dry weather continues into
Thursday, however isolated showers are possible Thursday
afternoon over NEPA as the front sneaks northward a bit and
afternoon heating aids in convection.

Short wave passing through on Friday will once again work with
afternoon heating to fore convection, mainly in the afternoon,
scattered over much of the area.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
230 AM UPDATE...

A cold front will sweep through the area Friday night into
Saturday triggering showers and thunderstorms over much of the
area. Long wave trough behind the front will allow for isolated
showers and storms Saturday with the cold pool aloft. Upper
heights begin to build in Sunday as the trough axis slides east
of New England and drier sir builds into the forecast area. The
dry weather will continue into Monday as a large ridge builds
into the Great Lakes by the end of the period.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
Mostly cloudy conditions, but with VFR ceilings will continue
for the remainder of the afternoon and into this evening.
Thereafter, conditions will fluctuate through the overnight
hours and through the day tomorrow. The first quick moving
disturbance will likely bring heavy showers and thunderstorms
late tonight into early tomorrow morning across the Southern
Tier of NY and into NE PA. Trapped shallow moisture behind the
first disturbance overnight could lower ceilings to IFR for KBGM
and KRME.

The next disturbance pushes into the region tomorrow morning,
mostly affecting terminals from the Southern Tier southward into
NE PA. Thunderstorms with strong winds will be possible into
tomorrow afternoon.

Outlook...

Wednesday night through Thursday night...Mainly VFR.

Friday through Friday night...Chance of showers and
thunderstorms with associated restrictions as front passes.

Saturday...Small chance of showers/restrictions, otherwise VFR.

Sunday...VFR expected at this time.

&&

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

&&

$$
SYNOPSIS...MPK
NEAR TERM...MPK
SHORT TERM...AJG/DGM
LONG TERM...DGM
AVIATION...MPK