307
FXUS61 KALY 251043
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
643 AM EDT Tue Jun 25 2024

.SYNOPSIS...
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.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 643 AM EDT...High pressure is building in WV/VA this
morning with clear/mostly clear skies and light to calm winds.
Patchy mist/fog will burn off quickly this morning near Lake
George and the CT River Valley in eastern Windham County, VT
with mostly sunny/sunny skies due to the subsidence with low and
mid level ridging aloft.

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.

&&

.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 /12Z TUESDAY THROUGH SATURDAY/...
IFR visibility with even periods of LIFR visibility will be
maintained at GFL through 11 UTC/25 due to fog formation under
radiational cooling conditons while ALB/POU remain VFR. We
removed the mention of fog development at PSF given current dew
point depression at over 5 degrees; however, ongoing radiational
cooling conditions will support additional cooling and as
temperatures at PSF cool into the mid-50s towards sunrise, some
patchy fog may form. Given how early sunrise is in late June,
did not have enough confidence to include MVFR visibility at
PSF, especially given lack of support in forecast soundings.
Will continue to monitor and adjust visibility forecast as
needed.

Early fog at GFL burns off by or shortly after 11 UTC. Then SKC
conditions expected at all terminals thanks to large scale
subsidence building in behind our departing upper level trough.
Cirrus clouds return after 00 UTC from west to east at all terminals
before mid-level clouds with ceilings around 10kft return. A few
isolated showers may approach ALB, POU, and GFL by or shortly after
03 UTC with the potential reaching PSF towards the end of the TAF
period. Given plenty of dry air beneath the cloud deck, maintained
VFR conditions as any light showers or sprinkles that arrive prior
to 06 UTC will likely not result in a flight category degradation.

Light and variable winds through 12 UTC. Then winds shift out of the
west or southwest by 14-16 UTC at all terminals and turn a bit
breezy becoming sustained 5-9kts and gusts reaching up to 15kts.
Strongest winds at ALB and PSF. Then, winds likely become light and
variable by 01 - 03 UTC at all terminals.

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.

&&

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

&&

$$

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