000
FXUS61 KBGM 162325
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
725 PM EDT Tue Jul 16 2019

.SYNOPSIS...
Heat and humidity builds through the end of the week thanks to
southerly return flow around a Bermuda high. A series of fast-
moving disturbances tracking across the northern U.S. along with
tropical moisture will produce several rounds of showers and
storms through the end of the week.

&&

.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
Diurnal instability with MLCAPE around 1000 J/kg combined with a
mid level short wave will keep thunderstorms across the area
until early evening. The most widespread coverage is expected
over the twin tiers. Airmass is becoming increasingly moist with
precipitable water values rising to 2 inches. Will continue to
mention heavy rain into the early evening.

Once this wave passes and instability decreases later this
evening coverage will drop to isolated until late tonight. After
06Z mid level short waves in southwest upper level flow will
track primarily across the northern forecast area. Will continue
to advertise categorical/likely POPs in the northern forecast
area by daybreak. A tropical airmass will reside over the region
on Wednesday with precipitable water values between 2.0-2.2
inches. Model soundings show tall/skinny CAPE with warm cloud
layer around 12K feet. Will mention the potential for heavy
rain Wednesday through Wednesday evening. Isolated flash
flooding is a possibility especially Wednesday afternoon/evening,
a watch may be issued by later shifts. A surface trough will
also drop south through the area during the afternoon and
evening enhancing the forcing. Models indicate better
instability in the far southeast during the late afternoon/evening
along with wind fields which could support some isolated severe
thunderstorms. The boundary will push the tropical airmass out
of the region late Wednesday evening and most likely end the
threat for flash flooding. Showers and isolated thunderstorms
will linger in the far southeast late evening through past
midnight then become scattered toward daybreak.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Hot, humid very summer like weather expected through this period. A
lingering mid level circulation will be across the east-central
portion of the area on Thursday. This will allow showers and
embedded thunderstorms mainly from I-81 east during the day.
Thursday will be warm and humid, with highs reaching well into the
80s and dew points in the low 70s. Thursday night will be mainly
dry, with just a low chance of a shower or thunderstorm; mild with
lows in the upper 60s to lower 70s. Then oppressive heat and
humidity build over the region Friday through Saturday. Model
guidance shows 1000-500mb thicknesses rising above 582dm, and 850 mb
temperatures around +20C to +22C. The hottest day now appears to be
Saturday. Current forecasts indicate highs 90 to 95 each day, with
localized higher numbers possible Saturday in the urban valleys.
These hot temperatures will combine with oppressive dew points in
the low to mid-70s to create apparent temperatures between 98-105 in
the afternoon and early evening hours. Again, some locally higher
heat index values are possible in the urban valleys, mainly on
Saturday. Record or near record highs seem likely both days. Staying
very warm Friday night, with not much relief...lows only dip into
the low or mid-70s.

Will hold off on any heat headlines at this time but there is
growing confidence that some will be needed later in the week. The
heat and humidity will be the main story during this time, but there
could also be some isolated or scattered thunderstorms late Friday
and again on Saturday around the periphery of the upper level
ridge.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
The upper level ridge begins to break down during this period
as energy digs into the northern Great Lakes region. Could still
see some shower or thunderstorm activity Saturday night on the
northern edge of the departing ridge. A boundary looks to setup
over the region on Sunday, which should allow for additional
scattered thunderstorm development. Depending on the exact
location of this boundary the heat and humidity will linger
south of it; although it should be at least several degrees
cooler than Saturday. Highs could still be in the upper 80s to
low 90s, with peak heat indices 92-97 in central NY and 95-102
for NE PA. Low pressure system and a fairly potent cold front
then moves through the area on Monday, bringing a better chance
for showers and thunderstorms along with more cloud cover.
Temperatures fall back into the 80s. Current timing has this
front moving through and east of the area later Monday night
with high pressure building by next Tuesday. This is a Canadian
high and is poised to finally put an end to the warm and humid
weather. If current forecasts hold, lows will fall back into the
50s or low 60s and highs will be seasonable in the 70s to near
80.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...

Upper wave triggering thunderstorms is now moving over the area
and will be east shortly. So, still a chance of a thunderstorm
for an hour or two at ELM and BGM, for the next few hours at
AVP. Overnight will feature VFR conditions becoming MVFR as yet
another wave approaches and develops showers and isolated
thunderstorms. The threat of showers and MVFR conditions will
linger through the end of the period.

Winds will be light and variable overnight becoming southwest
again Wednesday at 5-10 knots.

Outlook...

Wednesday night through Sunday...This unsettled weather pattern
continues with a series of disturbances providing chances for
showers and storms. Brief/localized restrictions possible. Even
with increasing moisture at the surface, the potential for fog
each night will depend on how much debris clouds are leftover
from diurnal convection.

&&

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

&&

$$
SYNOPSIS...RRM
NEAR TERM...RRM
SHORT TERM...HLC
LONG TERM...HLC
AVIATION...DGM/RRM

NWS BGM Office Area Forecast Discussion