632 
FXUS61 KBGM 061737
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
137 PM EDT Tue Aug 6 2019

.SYNOPSIS...
Increasing humidity will push into the region, which will allow
scattered thunderstorms to develop today, especially this 
afternoon through early evening. Some may contain gusty winds 
and heavy downpours. Wednesday and Thursday will also be 
unsettled with more showers and storms, but a drier pattern will
take shape towards the weekend.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
850 AM update...Some convection will be possible through the
morning hours as weak warm front crosses the area, so added 
slight chance PoP to the forecast until the main short
wave/pre-frontal trough arrives later this afternoon/evening.


330 AM update... 
Convection returns to the region during the near term period, 
and main concern will be prospects for gusty winds in a few of 
the strongest storms, as well as eventually locally heavy 
rainfall especially as we head into Wednesday.

With high pressure now shoving east, low level moisture will 
increase via south-southwest return flow. High Resolution 
Ensemble Forecast model (HREF) and operational model consensus 
indicate that along with heating ahead of an incoming pre- 
frontal trough, this will allow Convective Available Potential 
Energy (CAPE) to reach between 900-1500 J/kg. This should be 
adequate instability to realize a line of at least scattered if 
not broken thunderstorms as the trough sweeps through Central NY
and far northern PA between 3PM-9PM. Shear is weak with only 
about 20-25 kts within the 0-6 km layer. However, forecast 
soundings continue to indicate an inverted-V at the bottom, 
suggestive of downdraft CAPE (DCAPE). So directly under storm 
cores there could be strong localized downbursts. They will be 
mostly if not entirely subsevere, yet strong enough to impact 
small branches/powerlines. The best chance for stronger gusts 
and perhaps isolated severe, will be Central Southern Tier-
Finger Lakes region. Ahead of all of that, a weaker wave this 
morning to midday could actually touch off its own scattered 
showers-thunder mainly east of I-81, but confidence on that is 
low and none of that early activity would be strong. High 
temperatures today will be mainly upper 70s-mid 80s, though with
dewpoints creeping up into mid-upper 60s creating noticeable 
humidity. With that increasing moisture comes the potential for
heavier downpours from storms today, though that threat will be
higher Wednesday.

Overnight tonight, with a lack of forcing between waves and a loss
of diurnal heating, activity will diminish to isolated-scattered
showers and possible rogue thunder with lows in the 60s.

Wednesday is a similar set up, but a bit of an increase of 
magnitude. That is, more energy and higher precipitable water 
values as well as somewhat more shear. Coverage of showers and 
thunderstorms thus should be greater than today, with locally 
heavy rainfall and possible gusty winds. HREF probabilities 
suggest CAPE minimums of 1500-2000 J/kg this time, with 2500 
J/kg not out of the question especially towards Wyoming Valley-
Poconos-Southern Catskills. Shear while higher is still modest,
though combined with greater instability, prospects for some
cells with locally damaging winds will be higher Wednesday 
compared to today. The Storm Prediction Center thus includes our
area in a marginal risk for severe thunderstorms Wednesday. It
is possible that an initial smaller wave in the morning to
midday could hold back instability some, but if higher
instability gets realized then an upgrade in severe risk is not
out of the question. 

For Wednesday, precipitable water values meanwhile reach at 
least 1.6 inches in the models; for the NAM, even close to 2.0 
inches. This along with warm cloud depths of at least 11 kft 
points to locally heavy rainfall potential/brief yet high 
rainfall rates within the storms themselves. Thus urban and 
creek flooding is not out of the question within our general 
area, with chances somewhat higher towards Wyoming Valley-
Poconos-Catskills where probability of higher instability 
values is greater. Temperatures Wednesday again will reach upper
70s-mid 80s for highs with continued humid conditions as well.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
345 am update...
Multiple rounds of showers and storms are expected during the latter 
half of the week with a series of upper waves rotating through the 
area. 

Ongoing showers and thunderstorms along a weak surface cold front 
and lead upper short wave lifting e/newd out of the area will be the 
main concern Wednesday evening. Even though most of the strong 
convection will be either rapidly diminishing or have already moved 
out of the area, there is still expected to be scattered showers and 
a few lingering storms over the eastern half of the forecast area 
Wed evening. Lingering tropical-type moisture into the Poconos and 
Catskills main allow for a few heavier rain showers before midnight. 
However, during the overnight hours, a slightly drier air mass works 
in from the sw, which when combined with very brief and weak upper 
level ridging should allow conditions to dry out and most of the 
showers to taper off into Thursday morning. 

The reprieve Thursday morning will be relatively short-lived as
another round of showers and storms moves in Thursday 
afternoon/evening associated with another embedded wave rounding
the bottom of a larger upper trough over eastern Canada. This 
front will be faster and have less moisture to work with. 
However, the timing of the frontal passage could work positively
with the afternoon heating/destabilization enough to trigger 
more than anticipated convective showers and storms. The best 
chance appears to be across the Finger Lakes into the wrn 
Catskills into Thur evening. Temperatures will be mild/seasonal 
on Thursday with highs in the lower to mid 80s...and dew points
in the 60s. 

An even drier air mass arrives Friday, but another sharp upper 
wave...even amplifying a bit as it rotates through the ern Great 
Lakes into NY...could be enough to trigger an isolated shower in the 
afternoon. Temperatures on Friday will be noticeably cooler with 
highs only into the mid/upper 70s...and dew points in the mid
50s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
345 am update...
The weekend is expected to be very pleasant with mild temperatures, 
low humidity and nearly zero or very low chances for afternoon 
convection. Rising heights aloft and a rather deep layer of dry air 
advecting in from the west should keep skies mostly sunny in the day 
and generally clear overnight all the way into early next week.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
Timing of showers and thunderstorms is the main forecast problem
for this afternoon and into this evening. These storms could
bring brief IFR conditions if they were to come over any
particular site. Depending on where rain falls today, moisture 
could form restrictions overnight with low ceilings but
confidence is too low at this time to add IFR ceiling at any one
location.

Outlook... 

Wednesday through Thursday night...Restrictions possible in 
scattered showers and thunderstorms, especially during the afternoon-
evening. Depending on where the rain falls, moisture may cause 
overnight-early morning restrictions as well.

Friday through Sunday...Mainly VFR.

&&

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

&&

$$
SYNOPSIS...MDP
NEAR TERM...MPK/MDP
SHORT TERM...BJT
LONG TERM...BJT
AVIATION...MPK