ny discuss
Office: ALY
FXUS61 KALY 180208
AFDALY
Area Forecast Discussion
National Weather Service Albany NY
1008 PM EDT Fri Aug 17 2018
.SYNOPSIS...
A series of disturbances ahead of a cold front will bring rounds
of showers and thunderstorms today into tonight, some of which
could result in locally heavy rainfall and gusty winds. The cold
front will move through on Saturday along with continued showers
over portions of the area, but a drying trend from north to
south will take place. Some lingering showers are possible for
southern areas Sunday, but to the north it will be dry and not
as warm.
&&
.NEAR TERM /THROUGH SATURDAY/...
Severe Thunderstorm Watch has been cancelled.
As of 1000 PM EDT, Convection continues across the region as we
have transitioned toward a more heavy rainfall and flash flood
threat. As we will remain embedded within the deep warm moist
air mass overnight, adding to it the approach of the short wave
near western Lake Erie, additional convection is likely
overnight.
Prev Disc...Convection will likely continue into most of the
overnight as overall severe aspect should wane. We remain well
within the warm sector tonight as main surface low is expected
to track across the St Lawrence Valley. PWATs are expected to
remain near the 2 inch mark so rainfall can still be locally
heavy, especially where training can occur as trough aloft
remains positively tilted.
The cold front begins its approach Saturday morning with
additional showers and thunderstorms will likely continue. While
overall severe threat remains low, locally heavy downpours will
continue as those PWATs remain high along and ahead of the
front. SBCAPES south of I90 per the GFS/NAM suggest values
between 1000-1500 j/kg yet overall density looks minimal.
Temperatures will be cooler but where breaks of sunshine could
occur from the Capital District and points southward could touch
80F with mainly 70s elsewhere.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
Saturday night into Sunday night, model consensus still
supports the cold front finally clearing the area, keeping us
under cool easterly to northeasterly flow. However, there has
been a trend in some of the GEFS members and ECMWF to linger
the front just south of our area and develop a wave of low
pressure upon it as upper impulse approaches from the Ohio
Valley, opening the door for continued light showers through
the weekend. At this point, continued chance PoPs for our
eastern and southern tier of counties. Furthermore, easterly
component off the Atlantic could add low level moisture. Regardless,
cooler than normal temperatures are favored for highs Sunday.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
The extended begins with a weak wave of low pressure passing south
of Long Island. This sfc wave will focus some isolated to scattered
showers early Sunday evening mainly south and east of the Capital
Region. Some cooler and drier air will filter in for the opening of
the week with weak low and mid level riding building in based on the
latest GEFS/GFS/ECMWF for Monday. At the sfc, a weak sfc high
builds in with seasonable temps and fairly comfortable humidity
levels with sfc dewpts in the 50s to around 60F in few spots. Lows
fall back into the 50s to around 60F, and highs Monday with be in
the mid and upper 70s over the hills and in the valleys, and mid 60s
to lower 70s over the mountains.
Monday night into Tuesday...Mid and upper ridging shifts eastward
along the East Coast, as a fairly strong mid and upper level trough
will be approaching from the mid and upper MS River Valley. Monday
night will be fair and dry with the sfc high shifting east, but mid
and high level clouds will start to stream in from the south and
west ahead of the upstream systems warm front. Lows will be in the
mid 50s to lower 60s. The sfc wave moves into the Great Lakes
region. Some weak isentropic lift increase ahead of the warm front
advancing from the Mid Atlantic States, and lower Great Lakes
Region. A chance of showers and a slight chance of thunderstorms
will be possible especially from the Hudson River Valley westward.
Highs will be in the upper 70s to around 80F in the lower
elevations, and upper 60s to mid 70s over the higher terrain.
Tuesday night into Wednesday...The trough of low pressure at the sfc
and aloft quickly moves east to northeast into Quebec Tue night into
Wed morning with a cold or occluded front moving across the region.
Decent synoptic lift looks possible with showers likely and a chance
of thunderstorms. A secondary cold front moves through during the
day with at least a chance of showers or isolated thunderstorms.
Decent cold advection will occur during the afternoon and it will
become breezy with highs in the upper 60s to lower 70s over the
mountains north and west of the Capital Region, and 70s to lower 80s
in most other locations. Lows Tue night will be mild in the 60s
mainly.
Wednesday night through Friday...High pressure builds in from the
Midwest and Great Lakes Region Wed night into Thursday...and crests
over the region on Friday with fair, dry and tranquil weather with
temps near normal for late August.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
Scattered to numerous showers and thunderstorms will continue
through most of the evening and likely into the overnight period
with MVFR conditions, generally speaking. Impacts from deeper
convection will be sure to result in temporarily IFR conditions.
As cold front approaches on Saturday, still the threat for
additional showers and thunderstorms will be waning from north
to south with frontal passage. So combination of VFR/MVFR
conditions.
Winds will be from the south to southwest tonight at 5 to 12
kts. Winds will then shift from a westerly direction Saturday
in the morning before shifting from the north at KGFL first
Saturday afternoon.
Outlook...
Saturday Night: Low Operational Impact. NO SIG WX.
Sunday: Low Operational Impact. Slight Chance of SHRA.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: Moderate Operational Impact. Chance of SHRA...TSRA.
Tuesday Night: High Operational Impact. Likely SHRA...TSRA.
Wednesday: Moderate Operational Impact. Chance of SHRA...TSRA.
&&
.FIRE WEATHER...
A wet period is expected through at least most of Saturday,
keeping fire weather concerns to a minimum. Some showers may
linger into Sunday for southern areas, but to the north, a dry
northeast flow will set up along with temperatures slightly
below normal. Drier weather into early next week.
&&
.HYDROLOGY...
Another period of wet weather is in store through at least
tonight as a series of midlevel disturbances interact with a
moist airmass. Though there should be strong enough flow to
keep storm motions relatively fast, there is potential for
training given the deep southwesterly flow parallel to the
slowly approaching cold front, so locally heavy rainfall will be
a threat as well. PWAT values are forecast to be in the
vicinity of 2 inches once again. Urban and poor drainage
flooding is possible along with isolated flash flooding. The
Mohawk Valley and Catskills along with portions of western New
England have seen 150-300% of normal precipitation over the last
week per the last 7-day analysis, so they may be particularly
prone to flooding. Meanwhile, the latest Drought Monitor
indicates the southern Adirondacks are experiencing moderate
drought conditions.
Additional showers and thunderstorms will continue into Saturday with
a continued threat for locally heavy rainfall and possible
flooding if additional storms impact areas that saw rainfall
during the day. Deep-layer moisture will be on the decrease on
late Saturday from north to south reducing heavy rainfall
threat.
Although flooding of small streams and creeks is possible,
flooding on main stem rivers is not expected.
For details on specific area rivers and lakes, including
observed and forecast river stages and lake elevations, please
visit the Advanced Hydrologic Prediction Service /AHPS/ graphs
on our website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...Wasula
AVIATION...BGM/JVM
FIRE WEATHER...BGM/Thompson
HYDROLOGY...BGM/Thompson
Office: OKX
FXUS61 KOKX 180212
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1012 PM EDT Fri Aug 17 2018
.SYNOPSIS...
A cold front across the eastern Great Lakes slowly moves
southeast, toward the region, overnight. The cold front then
crosses the area Saturday into Saturday night. A series of lows
along the cold front south of Long Island will keep the frontal
boundary not too far away for the close of the weekend into
early next week. Meanwhile, high pressure from the Canadian
Maritimes will begin building down along the Northeastern
Seaboard. High pressure gets closer to the local region Monday
into Tuesday next week. A frontal system from the west moves
across Wednesday into Wednesday night with high pressure
returning thereafter.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
The severe thunderstorm watch was cancelled as the line of
thunderstorms moving through eastern NJ has weakened, with the
storms encountering somewhat more stable air as the gust front
moves out ahead of the line. Some gusty winds and heavy
rainfall will be possible with some of the stronger storms with
special weather statements possible. Surface instability and
CAPE to 2000 J/kg remain across the eastern zones.
A warm and humid airmass remains, with dew points still in the
lower to mid 70s, with some locations in the upper 70s, as the
cold front was still well to the northwest.
Will keep likely and chance probabilities as the upper shortwave
and impulses will be moving into the region overnight.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
The old front will be very slow to push southward across the
area. Some additional showers and thunderstorms are possible
Saturday as the upper trough axis remains to the west, through
upstate NY and into the Ohio Valley. Instability looks limited
lowering the potential for severe thunderstorm development,
precipitable waters will remain above normal and as a result any
thunderstorms that do development have the potential for heavy
downpours.
Temperatures on Saturday will be in the mid to upper 80s with
heat indices remaining below heat advisory criteria.
There is a low risk for the development of rip currents at the
Atlantic Ocean beaches Saturday.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Cooler and a little less humid conditions expected to start out
Sunday through Monday with more rain in the forecast Sunday and
Sunday night as the region gets more NE flow. Airmass warms up
for mid to late in the week, near normal levels with winds
having more westerly and southerly components.
Upper level trough will be slow to exist for the close of the
weekend. Trough axis will be west of the region Sunday and
Sunday night with jet streak across the region. The trough axis
moves across Monday. The steering flow will not promote the
front to move farther south of Long Island and with weak low
pressure areas forming along it, essentially keeping some rain
showers in the forecast for the region, highest chances along
the coast.
More drying takes place Monday when more ridging aloft and high
pressure at the surface will settle more southwestward along
the Northeastern Seaboard. Dry conditions remain until midweek
when the next frontal system approaches from the west. Aloft, a
large amplitude trough will be approaching with a stronger
southerly jet ahead of it. This jet moves in Wednesday night
into early Thursday. Chances for showers return Tuesday
afternoon and Tuesday night with highest chances N/W of NYC. The
chances for showers continues Wednesday with thunderstorms
possible as well as instability is forecast to increase again
with the airmass getting warmer and more humid. Dry conditions
return Thursday into Friday next week with high pressure
returning.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
Generally, VFR conditions through the TAF period. However, MVFR
conditions or lower are expected in any thunderstorms that move
through terminals. The most likely time period for this to
occur is between 01Z-03Z for the metro terminals as a
disturbance arrives tonight, which may weaken and thunderstorms
become sparse as they move through, thus KJFK has just VCTS as
opposed to a TEMPO of TSRA.
Additional scattered showers and thunderstorms possible
overnight through Sat morning, with MVFR cigs/vsby.
Winds S to SW tonight will shift to the SW to W late Sat
morning into the afternoon as a cold front moves through.
NY Metro Enhanced Aviation Weather Support...
Detailed information, including hourly TAF wind component forecasts,
can be found at: http:/www.weather.gov/zny/n90
KJFK TAF Comments: Sparse thunderstorm potential, mainly after
00z with MVFR cig/vsby possible and gusts 20-25 kt possible or
higher in any thunderstorm.
KLGA TAF Comments: Sparse thunderstorm potential, mainly after
00z with MVFR cig/vsby possible and gusts 20-25 kt possible or
higher in any thunderstorm.
KEWR TAF Comments: Sparse thunderstorm potential, mainly after
00z with MVFR cig/vsby possible and gusts 20-25 kt possible or
higher in any thunderstorm.
KTEB TAF Comments: Sparse thunderstorm potential, mainly after
00z with MVFR cig/vsby possible and gusts 20-25 kt possible or
higher in any thunderstorm.
KHPN TAF Comments: Sparse thunderstorm potential, mainly after
00z with MVFR cig/vsby possible and gusts 20-25 kt possible or
higher in any thunderstorm.
KISP TAF Comments: Isolated to scattered thunderstorm possible
after 01Z.
.OUTLOOK FOR 00Z SUNDAY THROUGH TUESDAY...
.Sat Night...Scattered showers/tstms. W flow becoming NE Sat
eve.
.Sun...Potential for MVFR conditions in shra and ne winds of
8-12kt.
.Mon-Tue..VFR.
.Tue Night-Wed...Chance of shower/tstm with MVFR conds.
&&
.MARINE...
Winds and seas remain below SCA levels overnight through
Saturday night across the forecast waters. Showers and
thunderstorms will continue to move through the area waters
overnight, and some gusty winds will be possible early,
especially across the western waters.
SCA conditions are possible on the ocean waters Sunday. Some
marginal SCA wind gusts are possible for non-ocean waters with
otherwise sub SCA conditions expected for all non-ocean waters.
Then, sub-SCA conditions are expected for all the forecast
waters early into the middle of next week but there is a
possibility the SCA seas could linger into Monday for the ocean.
Ocean seas could reach SCA criteria again Wednesday night into
Thursday.
&&
.HYDROLOGY...
Thunderstorms, with heavy to torrential rainfall, through
Saturday could result in minor urban flooding. There is also an
isolated flash flood threat with the strongest thunderstorms.
No significant widespread rainfall expected during the long
term.
&&
.EQUIPMENT...
NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) remains off
the air for an extended period of time.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...Fig/JM
NEAR TERM...MET
SHORT TERM...Fig
LONG TERM...JM
AVIATION...JP
MARINE...Fig/JM/MET
HYDROLOGY...Fig/JM/MET
EQUIPMENT...
FXUS61 KOKX 180249
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1049 PM EDT Fri Aug 17 2018
.SYNOPSIS...
A cold front across the eastern Great Lakes slowly moves
southeast, toward the region, overnight. The cold front then
crosses the area Saturday into Saturday night. A series of lows
along the cold front south of Long Island will keep the frontal
boundary not too far away for the close of the weekend into
early next week. Meanwhile, high pressure from the Canadian
Maritimes will begin building down along the Northeastern
Seaboard. High pressure gets closer to the local region Monday
into Tuesday next week. A frontal system from the west moves
across Wednesday into Wednesday night with high pressure
returning thereafter.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
The severe thunderstorm watch was cancelled as the line of
thunderstorms moving through eastern NJ has weakened, with the
storms encountering somewhat more stable air as the gust front
moves out ahead of the line. Some gusty winds and heavy
rainfall will be possible with some of the stronger storms with
special weather statements possible. Surface instability and
CAPE to 2000 J/kg remain across the eastern zones.
A warm and humid airmass remains, with dew points still in the
lower to mid 70s, with some locations in the upper 70s, as the
cold front was still well to the northwest.
Will keep likely and chance probabilities as the upper shortwave
and impulses will be moving into the region overnight.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
The old front will be very slow to push southward across the
area. Some additional showers and thunderstorms are possible
Saturday as the upper trough axis remains to the west, through
upstate NY and into the Ohio Valley. Instability looks limited
lowering the potential for severe thunderstorm development,
precipitable waters will remain above normal and as a result any
thunderstorms that do development have the potential for heavy
downpours.
Temperatures on Saturday will be in the mid to upper 80s with
heat indices remaining below heat advisory criteria.
There is a low risk for the development of rip currents at the
Atlantic Ocean beaches Saturday.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Cooler and a little less humid conditions expected to start out
Sunday through Monday with more rain in the forecast Sunday and
Sunday night as the region gets more NE flow. Airmass warms up
for mid to late in the week, near normal levels with winds
having more westerly and southerly components.
Upper level trough will be slow to exist for the close of the
weekend. Trough axis will be west of the region Sunday and
Sunday night with jet streak across the region. The trough axis
moves across Monday. The steering flow will not promote the
front to move farther south of Long Island and with weak low
pressure areas forming along it, essentially keeping some rain
showers in the forecast for the region, highest chances along
the coast.
More drying takes place Monday when more ridging aloft and high
pressure at the surface will settle more southwestward along
the Northeastern Seaboard. Dry conditions remain until midweek
when the next frontal system approaches from the west. Aloft, a
large amplitude trough will be approaching with a stronger
southerly jet ahead of it. This jet moves in Wednesday night
into early Thursday. Chances for showers return Tuesday
afternoon and Tuesday night with highest chances N/W of NYC. The
chances for showers continues Wednesday with thunderstorms
possible as well as instability is forecast to increase again
with the airmass getting warmer and more humid. Dry conditions
return Thursday into Friday next week with high pressure
returning.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
Generally, VFR through the TAF period, except MVFR or lower in
any showers and thunderstorms.
Showers and thunderstorms have weakened as they move across the
metro terminals. However, there continues to be isolated
lightning strikes. Additionally, there is another developing
area of showers and thunderstorms across northern New Jersey
that will likely affect the metro terminals, so VCTS was added
through 05Z. Thereafter, conditions may actually be dry for a
period until Saturday morning, though the chance still exists
for showers and thunderstorms.
Winds S to SW tonight will shift to the SW to W late Sat
morning into the afternoon as a cold front moves through.
.OUTLOOK FOR 00Z SUNDAY THROUGH TUESDAY...
.Sat Night...Scattered showers/tstms. W flow becoming NE Sat
eve.
.Sun...Potential for MVFR conditions in shra and ne winds of
8-12kt.
.Mon-Tue..VFR.
.Tue Night-Wed...Chance of shower/tstm with MVFR conds.
&&
.MARINE...
Winds and seas remain below SCA levels overnight through
Saturday night across the forecast waters. Showers and
thunderstorms will continue to move through the area waters
overnight, and some gusty winds will be possible early,
especially across the western waters.
SCA conditions are possible on the ocean waters Sunday. Some
marginal SCA wind gusts are possible for non-ocean waters with
otherwise sub SCA conditions expected for all non-ocean waters.
Then, sub-SCA conditions are expected for all the forecast
waters early into the middle of next week but there is a
possibility the SCA seas could linger into Monday for the ocean.
Ocean seas could reach SCA criteria again Wednesday night into
Thursday.
&&
.HYDROLOGY...
Thunderstorms, with heavy to torrential rainfall, through
Saturday could result in minor urban flooding. There is also an
isolated flash flood threat with the strongest thunderstorms.
No significant widespread rainfall expected during the long
term.
&&
.EQUIPMENT...
NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) remains off
the air for an extended period of time.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...Fig/JM
NEAR TERM...MET
SHORT TERM...Fig
LONG TERM...JM
AVIATION...JP
MARINE...Fig/JM/MET
HYDROLOGY...Fig/JM/MET
EQUIPMENT...
Office: BUF
FXUS61 KBUF 180305
AFDBUF
Area Forecast Discussion
National Weather Service Buffalo NY
1105 PM EDT Fri Aug 17 2018
.SYNOPSIS...
Low pressure will pass just to our north and slowly push a cold
front across the region late tonight into Saturday. This will result
more showers and thunderstorms which will taper off early Saturday.
Then high pressure will build into the region late Saturday and
bring a return to fair weather and more comfortable levels of
humidity for the remainder through Monday.
&&
.NEAR TERM /THROUGH SATURDAY/...
A shortwave trough will track eastward across Michigan tonight while
at the surface, low pressure is centered over the northern shore of
Lake Ontario. Showers and thunderstorms are likely across the
eastern Great Lakes tonight.
A moist airmass continues across the eastern Great Lakes with dew
points around 70 degrees this evening. Most of the afternoon/early
evening convection has moved east of the forecast area however,
instability is still present and with make it condusive for
showers and thunderstorms tonight. A disorganized line of
showers and thunderstorms extends along a cold front from
eastern Lake Ontario to the northern shore of Lake Erie. This
boundary will slowly sag southward as low pressure tracks
eastward into northern NY by Saturday morning. Steadier showers
and thunderstorms will enter the Lake Plains late tonight and
may bring significant rainfall to the Niagara Frontier with
enhanced surface convergence when the southwesterly flow up Lake
Erie encounters the northerly component of the surface front.
Showers and thunderstorms will also continue to form south of
Lake Erie and across the Western Southern Tier as the shortwave
trough approaches the region.
Showers and thunderstorms with this front should slowly drop
from north to south across the area tonight, gradually weakening
late as it becomes more stable. Given the moist environment,
locally heavy rainfall is still possible ahead of the front
tonight. Lows tonight will generally be in the 60s.
Model consensus is slightly slower with the front, and associated
showers lingering across the Southern Tier into Saturday morning.
Then expect a slow clearing trend closer to the lakes Saturday
afternoon, with lingering cloud cover closer to the departing front.
The boundary will usher in cooler and drier conditions. Expect highs
on Saturday to average in the mid to upper 70s with more comfortable
humidity levels.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
In the wake of Saturday's cold front/wave of low pressure...broad
but weak surface-based ridging extending from northern Quebec to
the Central Great Lakes will build southeastward into our region
Saturday night. Subsidence and drier air associated with the high
should provide our region with a dry night along with mainly clear
to partly cloudy skies...with the greatest amount of lingering cloud
cover found along our southeastern periphery...which will lie closer
to the departing surface wave/front. The incoming cooler/drier airmass
attendant to the high will also allow for more comfortable overnight
lows that will range from the upper 50s across the higher terrain
to the lower 60s across the lake plains...along with correspondingly
lower humidity levels.
On Sunday the axis of the surface ridge will settle directly across
our region...while weak/broad troughing will be in place aloft.
While the combination of lingering low level moisture and the
development of some weak diurnally-driven instability could lead
to the development of an isolated shower/thunderstorm or two across
portions of the southern Finger Lakes and south-central New York...
our region should remain under the influence of relatively drier
air and therefore dry...with just a diurnal cumulus field developing
inland from the lakes. As for high temperatures...these will be close
to normal and will range from the mid/upper 70s across the higher
terrain to around 80 across the lake plains...while humidity will be
at moderate levels (i.e., dewpoints of around 60).
Sunday night and Monday the axis of the surface ridge will remain
draped firmly across our region...while the weak troughing aloft
will give way to gradually rebounding heights out ahead of the next
mid-level trough...which will be in the process of pushing across the
nation's midsection. This should promote continued quiet and dry
weather...with skies ranging from mainly clear to partly cloudy
Sunday night...then averaging out partly to mostly sunny on Monday.
Meanwhile temperatures will average out a bit above seasonal normals...
with lows in the upper 50s to mid 60s Sunday night followed by highs
mostly in the lower 80s on Monday. It will also turn a little more
humid...with surface dewpoints eventually creeping up into the lower
to mid 60s by Monday afternoon.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
The most active weather in the longer term portion of the forecast
will come within the first 36 hours of this period...when a broad
upper level trough digging southeastward across the Great Lakes will
capture and phase with a second mid/upper level trough over the mid-
Mississippi Valley...with the resultant deepening longwave trough
axis sliding eastward across the Great Lakes and Ohio Valley. At the
surface...increasing DCVA/height falls on the eastern flank of the
newly phased longwave trough will spur the continued development/
strengthening of low pressure that will track from Missouri to the
Central Great Lakes by Tuesday afternoon...then on into into Southern
Quebec Tuesday night. As it does so...this system will push its
attendant warm front across our region between late Monday night
and Tuesday morning...quickly followed by its trailing cold front
late Tuesday and Tuesday night. The latest medium range models remain
in excellent agreement that this will become an increasingly dynamic
system as it passes by to our northwest Tuesday and Tuesday night...
with the GEM/GFS/ECMWF all suggesting that the low will deepen to at
least below 1000 mb during this time frame...which would most
definitely be an anomalously strong system for this time of year.
Plentiful synoptic forcing and deepening moisture (PWATs increasing
to around 2 inches) attendant to this strengthening system will drive
the development of increasingly widespread precipitation through the
course of Tuesday and Tuesday evening...for which PoPs have again
been bumped up into the categorical range. Given what appear to be
only limited to modest levels of instability at this still somewhat-
distant vantage point...much of the precipitation from this system
should come in the form of plain rain showers...though some embedded
scattered thunderstorms will certainly be possible given both the
increasing dynamics and rather moisture-rich environment. Despite the
latter...at this juncture the potential for locally heavy rain/flash
flooding looks to be on the marginal side and largely dependent on
whether any training of cells can occur given the increasing wind
fields that will be in place aloft...with the threat for severe storms
also appearing to be rather marginal given currently unimpressive
projections of available instability. Nonetheless...such threats can
also not be entirely ruled out either given the strengthening and
increasingly dynamic nature of this system.
Following the passage of the trailing cold front...the arrival of
cooler and drier air will bring an end to the more widespread
precipitation Tuesday night...though the passage of main upper
trough axis/attendant cool pool core...diurnal heating...and
residual lower level moisture may still be sufficient to pop a few
more scattered showers/isolated storms inland from the lakes during
the day Wednesday. After that...high pressure and drier air will
continue to build into the region Wednesday night and Thursday and
bring about a return to completely dry weather...which should then
last through the end of the work week as this feature slowly drifts
eastward and off the mid-Atlantic coastline.
As for temperatures...these will average out close to normal through
the period...with readings briefly dipping back to slightly below
average levels for midweek following the passage of Tuesday night's
cold front. Meanwhile...uncomfortable dewpoints in the mid-upper 60s
on Tuesday will trend downward to much more comfortable levels in the
50s for Wednesday and Thursday in the wake of the cold front...before
rebounding slightly on Friday as a southerly return flow sets up on
the backside of the departing surface ridge.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
Low pressure will track to the north of the area with an associated
cold front slowly dropping across the area from north to south late
tonight into Saturday morning. For the remainder of this evening,
expect isolated showers and thunderstorms with a mix of VFR and MVFR
conditions.
Expect steadier showers with embedded thunderstorms along and just
ahead of the front tonight. This should generally result in a period
of MVFR conditions as it moves through between 04-12Z.
The northerly flow behind the front will upslope and trap low
moisture with a period of IFR conditions likely late tonight and
well into Saturday morning. Drier air will gradually build in late
morning and through the afternoon with clouds lifting and scattered
to VFR.
Outlook...
Saturday night through Monday...VFR.
Tuesday...MVFR. Showers and thunderstorms likely.
Wednesday...Mainly VFR. A chance of showers.
&&
.MARINE...
Low pressure will pass to the north with its associated cold front
dropping across the lower Great Lakes tonight. This evening,
southwest winds will continue. Isolated to scattered thunderstorms
may produce a period of gusty winds and Special Marine Warnings can
not be ruled out this evening.
Northerly component winds will pick up behind the front late
tonight into Saturday morning. Conditions will approach small craft
criteria along the south shores of Lake Ontario, but probably fall
just short.
After this, high pressure will ridge toward the waters Saturday
afternoon with diminishing winds. The ridge will expand across the
lower Great Lakes Sunday and Monday with negligible winds and waves.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...None.
&&
$$
SYNOPSIS...Apffel
NEAR TERM...Apffel/HSK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...Apffel/HSK
MARINE...Apffel/HSK
Office: BGM
FXUS61 KBGM 180230
AFDBGM
Area Forecast Discussion
National Weather Service Binghamton NY
1030 PM EDT Fri Aug 17 2018
.SYNOPSIS...
A cold front will settle across the area overnight into
Saturday with continued scattered showers and thunderstorms,
mainly from the Southern Tier and Catskills of New York, to
Northeast Pennsylvania. Though an isolated thunderstorm cannot
be ruled out Sunday, high pressure will build into the region
which will provide generally dry weather through Monday.
&&
.NEAR TERM /THROUGH SATURDAY/...
1030 PM Update...
Remainder of Watch was dropped prior to 10pm. A few showers and
even isolated thunder may occur overnight, but things overall
are looking pretty quiet. However, new convection is expected to
develop late morning into afternoon Saturday as the surface
front drifts south into Pennsylvania. Overall rain amounts do
not appear that heavy with lower precipitable water values, more
scattered coverage, and cells with good movement. However, with
the very wet ground unable to deal well with yet even more
rainfall, isolated flash flooding still cannot be totally ruled
out even though the threat will be considerably lower than it
was this past afternoon. The Weather Prediction Center thus
includes part of Northeast PA into Sullivan County NY in the
marginal risk for excessive rainfall on Saturday.
Previous discussion...
As of 745 PM, Severe Thunderstorm Watch remains in effect for
some parts of the area along and east of I-81, where clusters of
thunderstorms are still ongoing. However, the weak midlevel
lapse rates and limited forcing is definitely being realized,
with the storms struggling to achieve gusts even above 35 mph at
this point. We anticipate the remainder of the Watch will be
dropped well ahead of its scheduled 11 PM expiration. As for
rainfall, these storms have at times produced one hour rainfall
amounts in excess of a half inch, but most locations less. We
hoisted a few Flood Advisories for where the most sensitive
locations lined up with heavier rain as storm clusters moved
through. We will still have to keep an eye on prospects for
isolated flash flooding in the Poconos-Catskills zones,
especially where earlier initial cells already went through and
additional ones continue.
Tonight: The front will move southeast into the region
overnight with some additional scattered showers and a rumble of
thunder. Low temperatures will be kept up in the 60's due to
clouds and rain.
Saturday and Saturday night: The cold front will be very slow to
push southward through the region. Clouds will be fairly widespread
to start the day with some breaks of sunshine in the afternoon the
farther north you go. Some additional showers and thunderstorms will
refire around the eastern Southern Tier-Catskills of NY and drop
through Northeast PA during the afternoon hours. Highs should
be in the 70's with model guidance likely a touch cool north and
warm south based on the cloud cover. Overall, clearing should
continue into Saturday night across most of NY with lingering
showers across NE PA near the front. Lows Saturday night will be
in the 60's.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
Frontal boundary remains well to the south but the models show a
weak inverted trough and an upper wave passing to the north so
there is a small chance of a shower or storm on Sunday,
especially early. During the later afternoon, ridging builds
back in at the surface and aloft so anything that does develop
should be isolated and short lived.
Heights build slowly on Monday as a southerly flow develops at
the surface. This should keep the area warm but generally dry to
start the work week.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Deepening low moves rapidly from the central Great Lakes to
southwest Ontario on Tuesday into early Wednesday. This will
bring unstable air and scattered convection Tuesday afternoon,
and then more likely Tuesday night as a cold front sweeps
through. Instability will linger through Wednesday with an
upper trough and northwest flow.
High pressure will build in on Thursday bringing drier air and
seasonable temperatures.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
Clusters of showers and thunderstorms went across the terminals
prior to 00Z, and still around KAVP at 00Z. However, activity
will quickly wane with loss of instability. A shallow cold front
will be settling north to south over the area during the course
of this TAF period. Moisture trapped under the developing
subsidence inversion behind the front will cause an MVFR
ceiling, likely into fuel alternate required category for at
least the NY terminals, late tonight. A spotty shower and
perhaps even a rogue rumble of thunder cannot be ruled out. The
ceilings will be tough to get rid of during the day Saturday,
as winds veer northwesterly while picking up to around 5-10
knots and the subsidence inversion strengthens. Additionally,
some showers are likely along and just north of the front for at
least KBGM- KAVP. Thunder is possible but confidence not high
enough to include in TAFs yet. Ceilings may scatter out late in
the day for KSYR- KRME as drier air attempts to work in.
Outlook...
Saturday night through Monday...Mainly VFR, though late night-
early morning valley fog possible especially KELM.
Tuesday and Tuesday night...Restrictions possible in showers and
thunderstorms.
Wednesday... Improving to VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...MDP/MWG
NEAR TERM...MDP/MWG
SHORT TERM...DGM
LONG TERM...DGM
AVIATION...MDP
