443
FXUS61 KALY 141057
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
657 AM EDT Tue May 14 2024

.SYNOPSIS...
Morning sun today will mix behind increasing afternoon
clouds with temperatures becoming warm and summer-like. A weak cold
front will result in scattered showers and thunderstorms this
afternoon, especially north of Interstate 90, with storms capable of
brief downpours. Chances for showers continue Tuesday night and
Wednesday before turning more scattered for Thursday as an upper
level disturbance tracks to our south.

&&

.NEAR TERM /THROUGH TONIGHT/...

As of 6:50am...Latest GOES 16 satellite imagery show mainly
sunny skies in place to start our Tuesday morning with our warm
front well to our northeast and a weak cold front positioned
over southern Ontario near the international border. Despite the
clear skies, temperatures remained mild overnight with lows
only dropping into the 50s thanks to us being in the warm
sector. Some patchy fog developed as well but will quickly burn
off as the strong May sun angle continues to rise. Otherwise, we
will enjoy sun and dry weather through early afternoon with
high temperatures still expected to reach into the low 80s in
the valley. We delayed the onset of chance POPs based on the
latest CAM guidance which delays showers and storms spilling
into our southern Adirondack areas until near or shortly after
18 UTC.

Previous discussion..We are in store for a summer-like day
today as a warm front remains mainly north of our area and upper
level ridging and southwesterly flow aloft ushers in a very
warm air mass into eastern NY and western New England. 850hPa
isotherms reaching +10C to +11C, a period of mainly sunny skies
through early afternoon and drier air filtering into the low and
mid- levels should all support deep boundary mixing resulting
in afternoon high temperatures reaching well into the 70s with
low 80s in the Mohawk and Hudson Valley. Dew points luckily will
only be in the 50s thanks to the deep mixing so it will not
feel overly humid despite the summer-like temperatures. We
leaned on the warmer end of guidance for high temperatures given
the dry and sunny conditions expected through early afternoon.

Chances for showers and thunderstorms increase this afternoon,
especially for the southern Adirondacks and Upper Hudson Valley
as a weak/diffuse boundary from southern Ontario slowly sinks
south and eastward. Since the thermal and moisture gradient
along this boundary is weak and upper level ridging really does
not flatten out until tonight, we limited likely POPs to areas
north and west of the Capital District with just chance and
slight chance POPs for areas from I-90 southward. CAMs and high
res guidance support this thinking as well. Areas in the mid-
Hudson Valley and Litchfield Hills have the greatest likelihood
of remaining mainly dry today as they are displaced furthest
south and east from the boundary.

The air mass ahead of the front looks to destabilize this
afternoon as showalter values trend towards 0 and mid-level
lapse steepen to around 6C/km. Dew points in the 50s should
combine with insolation to lead to SB CAPE values ranging 500 -
1000J/kg. The lower dew points should limit the overall amount
of SB CAPE that develops but should still be sufficient to
support storms. Deep layer shear is not very strong at just
25-30kts but should be strong enough that some gusty winds winds
and small hail (thanks to wet-bulb zero heights under 10kft) are
not completely ruled out in any stronger storms. But strong
storms should be isolated at best given weak overall forcing. PWATs
rise above 1" ahead of the front so any thunderstorms will be
capable of producing brief heavy downpours.

An upper level shortwave trough from the Midwest slowly tracks
into the Ohio Valley tonight with our weak/diffuse boundary
lifting northward back into the North Country. Gradual height
falls and weak embedded shortwaves ahead of the trough spilling
into the region will support continued showers overnight. Instability
wanes after sunset so chances for thunderstorms diminishes by
00 - 03 UTC. CAMs and deterministic guidance are in rather good
agreement that periods of rain track north and eastward into our
region overnight due to the incoming shortwaves, increased
moisture, and weak warm air advection. We therefore increased
POPS to likely and high end chance for much of eastern NY and
western New England overnight. Otherwise, cloudy skies and
elevated dew points in the 50s to near 60 should support a
warm and even somewhat muggy night with overnight lows only
dropping into the mid to upper 50s with near 60 in the valley.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
The upper level trough from the Ohio Valley continues its slow
eastward push through the day Wednesday with weak height falls
continuing to spread in the Northeast. Moisture streams
northeastward and will become focused along the aforementioned
weak boundary as it sinks back southward towards the western
and southern Adirondacks. While overall forcing is weak and
muddled, plenty of mid-level moisture will likely support mostly cloudy
skies for much of the day which when combined with south to
southeasterly winds, temperatures should trend cooler compared
to Tuesday only reaching into the 60s to low 70s. We once again
placed likely POPs closer to our weak boundary in areas mainly
north and west of Albany with just chance POPs elsewhere. Not
expecting a washout of day but there will likely be on and off
showers around much of the day. POPs trend lower by late
afternoon as high pressure positioned off the New England coast
builds inland which should suppress shower activity, especially
for areas near and east of the Hudson.

Our weak boundary once again lifts northward Wednesday night as
our upper level trough slides into the mid-Atlantic. Showers
from this trough could scrape southern zones including the mid-
Hudson Valley and NW CT overnight but given some forecast
uncertainty, continued to message generally widespread chance
POPs overnight. Temperatures again remain mild thanks to clouds
and the muggy air mass with lows only in the mid to upper 50s.

The Thursday forecast has trended a bit more pessimistic
compared to a few days as guidance is in better agreement that the
upper level trough will still be around and thus influence our
sensible weather. While the shortwave will be weakly closed off
and centered well to our south over DE/southern NJ, upper level
divergence and its warm conveyor belt look to extend into far
southern zones including the mid-Hudson Valley and NW CT
supporting showers. We therefore continue to message chance POPs
here for much of the day. Further north, the weak boundary sinks
back southward into the southern Adirondacks and Upper Hudson
Valley which should support scattered shower and even a slight
chance thunderstorm activity. However, the Capital District and
I-90 corridor into Berkshire County and southern VT could
actually escape rather unscathed from showers on Thursday as
high pressure off the New England coast looks to provide enough
subsidence to suppress showers with clouds even thinning or
breaking for sun. Given the reduced POPs and increased sun
potential, temperatures here should actually be the warmest in
the forecast area with highs reaching into the mid-70s. We
actually leaned on the warmer end of guidance for temperatures
here given the potential for breaks of sun. Elsewhere where
shower potential is higher and sfc winds will be out of the
east-northeast, temperatures should be a bit cooler only
reaching into the upper 60s to around 70.

Showers and clouds diminish Thursday night as our slow moving
upper level low finally exits off shore and upper level ridging
builds in its wake. Overnight lows drop into the low to mid 50s.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Despite persisting uncertainty surrounding the evolution of key
features that will drive expected conditions throughout the extended
forecast period, general consensus points toward an unsettled
pattern that will lead to potentially multiple rounds of showers and
occasional thunderstorms for eastern New York and western New
England....

Friday looks to be a mainly dry day with high pressure nosing in
across the region between a coastal low spinning just off the Mid-
Atlantic and New England Coastlines and an approaching upper-level
disturbance to the west. Highs look to be in the upper 60s to mid
70s despite an expected fair amount of cloud cover. Multiple rounds
of showers become possible beginning late Saturday morning/early
Saturday afternoon and through possibly the remainder of the
forecast period as eastern New York and western New England become
influenced by two upper-level disturbances: a northern-stream,
negatively-tilted wave and a southern stream shortwave potentially
evolving over time into a cutoff low. While it is still uncertain
how these two features will interact, models generally agree, at
this time, in the lack of phasing of these two disturbances.
Therefore, showers look to initially result from the swift rotation
of the northern-stream wave about the region Saturday. Additional
showers Sunday and possibly some embedded rumbles of thunder Monday
would result from the approach of the southern-stream, cutoff low.
However, confidence is low pertaining to spatial spread and duration
of these additional showers given the amount of uncertainty in the
evolution of this feature. One consistency that does exist, however,
is light QPF despite the possible multiple days worth of showers.
Will continue to monitor trends over the coming days.


High temperatures Saturday look to be the coolest of the long term
period with primarily 60s and pockets near 70 across the region.
Sunday will feature temperatures in the upper 60s to mid 70s much
like Friday with low to upper 70s expected Monday. Low temperatures
throughout the period will fall in the upper 40s to 50s.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
Through 06z Wednesday...VFR conditions prevail at all terminals
this morning with variable cloud cover across eastern New York
and western New England. Such conditions are anticipated to
remain steady throughout much of the 06z TAF period despite the
expectation of a gradual increase in cloud cover in response to
a nearing low pressure system and associate cold front.
However, with plenty of low- level dry air as shown on latest
forecast soundings, developing ceilings will remain at heights
well within VFR thresholds.

The only way that VFR conditions will be disturbed throughout
this 06z cycle is in the event a shower or thunderstorm cross
one of the terminals later this evening. Latest models show
convection to be highly scattered in nature, with the most
consistent signal for a few showers or thunderstorms to impact
the KGFL terminal. Therefore, included a PROB30 group for a
period of light showers at KGFL later in the period. However,
until confidence grows in the spatial coverage and likelihood of
thunderstorms, left thunder out of the TAFs. Additionally, with
such a scattered nature to any precipitation, left any showers
out of the other terminals until, once again, confidence
increases in whether or not they could be impacted. It is also
possible, based on latest guidance, that showers could remain
outside of the duration of this cycle. Will provide further
details in later updates.

Winds throughout the 06z period will prevail out of a south to
southwest direction at sustained speeds of 6-12 kt. A few gusts
at KALB and KPSF are likely at speeds of 20-25 kt.

Outlook...

Wednesday Night: Moderate Operational Impact. Chance of SHRA.
Thursday: Low Operational Impact. Slight Chance of SHRA.
Thursday Night: No Operational Impact. NO SIG WX.
Friday: Low Operational Impact. Slight Chance of SHRA.
Friday Night: Low Operational Impact. Slight Chance of SHRA.
Saturday: Moderate Operational Impact. Chance of SHRA.
Saturday Night: Moderate Operational Impact. Chance of SHRA.
Sunday: Moderate Operational Impact. Chance of SHRA.

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.

&&

$$

SYNOPSIS...Speciale
NEAR TERM...Speciale
SHORT TERM...Speciale
LONG TERM...Gitro
AVIATION...Gant