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886
FXUS61 KALY 251736
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
136 PM EDT Tue Jun 25 2024

.SYNOPSIS...
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High pressure builds in from the Mid Atlantic Region today with
mostly sunny skies and dry weather as temperatures rise back
above normal. A warm front moves through tonight with increasing
clouds and a few showers and thunderstorms. A cold front will
bring widespread showers and thunderstorms late Wednesday
afternoon into Wednesday night, as a cooler and drier air mass
builds in Thursday through Friday.
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&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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.UPDATE...Decent mixing this afternoon resulting in lowering
dewpoints(mainly 50 to lower 60s) and temperatures running
slightly warmer than forecast in some areas. Made some minor
adjustments to account for these trends, otherwise no changes
with this update. Satellite imagery showing streaks of high
level cirrus clouds moving in from the west.

.PREV DISCUSSION[1019]...No significant changes with this
update. Temperatures are warming quickly this morning after a
relatively cool start to the day. High level clouds will
increase from the west this afternoon.

H850 temps will rise to about +1 to +2 STDEVs above normal as
the actual values will be in the +14C to +17C range. Humidity
levels will be comfortable with dewpoints in the 50s to around
60F in a few spots. Expect max temps to be close to the NBM/MAV
MOS values with mid and upper 80s in the valley areas with a few
90F readings in the mid Hudson Valley and mid 70s to lower 80s
over the higher terrain. Winds will be lighter than yesterday
and be from the west to southwest at 5-15 mph. Some cirrus will
begin to increase in the late pm from the south and west ahead
of a warm front.
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&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
Tonight...A warm front approaches the region from the south and
west. Mid and high clouds increase. Low to mid level warm
advection continues. Some elevated instability associated with
the warm front and a weak mid level disturbance will bring some
isolated to scattered showers and isolated thunderstorms
especially north and west of the mid Hudson Valley. The
thunderstorms may be more confined to the Adirondacks, w-central
Mohawk Valley and the northern Catskills. Low temps will be
milder with mid and upper 60s over the lower elevations and
upper 50s to lower/mid 60s over the hills and mtns.

The forecast area enters a warm sector on Wednesday and it
becomes moderately humid. The latest short-range and CAM
guidance is hinting at a drier day with perhaps some showers and
thunderstorms getting into locations south and west of the
Capital Region in the late afternoon and early evening. The
latest HREFS has mean MUCAPEs of 750-1000 J/kg over the southern
most zones of the southeast Catskills, mid Hudson Valley and NW
CT with 0-6 km shear values around 35 KT. A few stronger
thunderstorms may develop. The SPC Day 2 Outlook did not change
much with a Slight Risk over the eastern Catskills, Mid Hudson
Valley. A Marginal Risk continues over most of the rest of the
forecast area. A few stronger storms are possible into the early
evening, but the instability will be decreasing. The latest
3-km NAM shows the best MLCAPE and 0-6 km shear overlay towards
00Z/THU close to the I-84 corridor with the short-wave trough
and the cold front. Any severe threat will likely be damaging
winds or marginal severe hail. Max temps will generally be in
the mid and upper 80s in the valleys with 70s to lower 80s over
the higher terrain. Heat indices look to remain below 95F for
the mid Hudson River Valley, so a heat advisory is not
anticipated at this time.

PWATs rise +1 to +2 STDEVS above normal into the 1.25-1.75"
range. A secondary wave along the boundary will increase the
showers and embedded thunderstorms WED night for moderate to
locally heavy rain. The front is somewhat progressive and this
should limit the flash flood threat. WPC has a Marginal Risk
over the entire forecast area...so an isolated flash flood can
not be ruled out. Some 1-2" or so rainfall tallies will be
possible. Lows due to wet bulb cooling and cold advection in the
wake of the front will be in the 50s to lower 60s.

Fairly good confidence in the ensembles and medium range
guidance that the front will move through the region quickly by
daybreak Thursday. A few showers may persist in the morning over
western New England and the southern Adirondacks, as the the
mid and upper level trough axis move trough. High pressure
builds in from the Great Lakes Region. In the cyclonic flow
aloft it will be cool with sun mixed with a few clouds. Max
temps will be in the mid 60s to lower/mid 70s over the higher
terrain. Highs below 1000 ft in elevation will range from the
mid 70s to lower 80s. Humidity levels will be comfortable. The
sfc anticyclone builds in over NY and New England with ideal
radiational cooling conditions with clear skies and light/calm
winds. Lows will fall into the 40s to lower/mid 50s.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
We begin the long term period with large scale subsidence building
behind our departing trough from Thursday resulting in strengthening
high pressure for Friday. This will yield tranquil weather with
plenty of sunshine for final day of the work week and seasonable
temperatures rising into the upper 70s to low 80s with low humidity.

Our attention then turns to an incoming trough for the weekend.
Guidance is in good agreement with high pressure maintaining control
of the Northeast Friday night into the first half of Saturday before
a warm front progresses northward. Within the incoming warm sector,
increasingly rich low and mid-level moisture with PWATs exceeding
1.50" and potentially even 2" advects into the Northeast and looks
to restrict boundary layer mixing/insolation and thus high
temperatures appear to remain only around normal albeit increasing
humidity. Should insolation end up being higher with the deeper
moisture delayed until evening, daytime temperatures may trend
warmer for Saturday.

Strengthening warm air and moisture advection along the leading edge
of the warm nose support POPs increasing to chances (30-50%) and
likely (50-70%) for rain and thunderstorms Saturday afternoon into
especially Saturday night when the stronger height falls arrive.
Guidance is in good agreement keeping the main parent trough and sfc
cold front displaced well to our west over the Great Lakes and
western NY so we remain in the warm sector Saturday night into
Sunday. This should support even warmer daytime temperatures for
Sunday as strong flow ahead of the incoming cold front results in
even higher humidity. Parts of the mid-Hudson Valley may reach heat
advisory criteria but still enough uncertainty to keep this out of
the hazardous weather outlook. Ensemble guidance supports the slow
progression of the incoming trough and sfc cold front which is why
we maintained POPs at chance (30-50% ) for much of Sunday before the
main thermal and moisture gradient finally pushes through eastern NY
and western New England with the trough axis following in its wake.

Much cooler and drier air quickly infiltrates behind the cold front
for Sunday night into Monday with winds also turning breezy. Dry
weather continues into Tuesday and seasonable temperatures as high
pressure from the Great Lakes builds into the Northeast.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
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Through 18z Wednesday...VFR conditions are expected to prevail
through the 24 hour TAF period. High level cirrus clouds will
continue to increase this afternoon and thicken through this
evening. Cigs will lower to 6000-10000 ft AGL overnight
associated with a warm front moving through. Widely SCT -SHRA
are possible, especially in the KALB-KGFL corridor, so will
mention VCSH at these sites. Mid level clouds are expected to
decrease after 12z Wednesday behind the warm front, with mainly
FEW cumulus clouds and SCT high level cirrus clouds around.

Added mention of low level wind shear at KPOU/KPSF from around
06z onward tonight due to just enough of a wind speed difference
(30 kt difference) between the surface and 2000 ft AGL as a
southwest jet of around 40 kt moves in. LLWS should dissipate
after 12z once deeper mixing commences.

Surface winds will be mainly west-southwest around 8-10 kt with
occasional gusts to 15 kt through the daylight hours. Winds
will become south-southwest around 3-6 kt this evening,
increasing to 5-10 kt overnight.

Outlook...

Wednesday Night: High Operational Impact. Definite SHRA...TSRA.
Thursday: Low Operational Impact. Breezy. NO SIG WX.
Thursday Night: No Operational Impact. NO SIG WX.
Friday: No Operational Impact. NO SIG WX.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: Moderate Operational Impact. Chance of SHRA...TSRA.
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&&

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

&&

$$

SYNOPSIS...Wasula
NEAR TERM...JPV/Wasula
SHORT TERM...Wasula
LONG TERM...Speciale
AVIATION...JPV