Albany, NY WFO Forecast Discussion

Forecast Discussion for ALY NWS Office
000
FXUS61 KALY 250527
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
127 AM EDT Sun Sep 25 2022

.SYNOPSIS...
Chances for showers and some thunderstorms will increase on
Sunday as a low pressure system approaches from the west.
Unsettled weather will persist through early next week, as a
cold front will be very slow to move across the Northeast.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
.UPDATE...Satellite imagery indicating mid level clouds moving
in rather rapidly from the west, so sped up increase in cloud
cover overnight and subsequently removed mention of fog with the
clouds increasing quicker. Temperatures will likely hold fairly
steady through the rest of the night after the clouds move in.

.PREVIOUS[1102]...The ridging across the region will be
surpressed as an upper low and deepening trough approach. Clouds
will be on the increase overnight with mostly clear much of the
evening. The mostly clear skies along light and variable to
calm winds will allow temperatures to drop down into mainly the
40s by late this evening, then they are expected to hold rather
steady for the overnight. Some patchy fog will be possible
overnight in locations favorable for its development.

Upper low in the western Great Lakes will approach and as warm
advection increases, mid and high clouds will spread across our
region, especially after midnight. Some radiational cooling this
evening will help temperatures drop, and then temperatures
should hold steady or slowly drop through daybreak. Lows in the
40s with around 40 in parts of the southern Adirondacks and Lake
George Region to southern VT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
Upper low helps develop a northern stream mean upper trough with
axis west of our region Sunday through Tuesday. The upper low
will track through the southern periphery of the upper trough
Sunday into early Monday. Boundary layer winds will become
southwest and increase through the day Sunday as the upper low
and associated upper dynamics and upper level jet segment
tracks just south of our region. Much of our region will be in
the left exit region of an upper jet segment and some
instability and shear will be present south of the Capital
Region through southern Berkshires and NW CT late Sunday
afternoon and evening.

CAPEs Sunday afternoon could approach 1000 j/kg from the eastern
Catskills through mid Hudson Valley, southern Berkshires and NW
CT with mean 0-6km shear over 40Kt. Low level forcing will be
lacking as there is very weak cold advection and boundary layer
equivalent potential temperatures gradient is very weak. Still,
if any thunderstorms form, some could be strong to marginally
severe with isolated damaging winds. SPC put southern areas in a
marginal risk for severe thunderstorms.

Highs Sunday in the 60s with around 70 to lower 70s mid Hudson
Valley and NW CT and around 60 to lower 60s in higher terrain.
Coverage of showers and isolated to scattered thunderstorms
decreases through Sunday evening and night.

Another upper impulse within the mean northern stream upper
troughing approaches Monday into Tuesday with another upper jet
segment tracking south of our region, putting our area in the
left exit region of the upper jet. Continued strong southwest
boundary layer winds in our region and increasing upper
dynamics will support additional development of showers and
scattered thunderstorms. Low level forcing will once again be
weak with such slow and gradual cooling at the boundary layer
but some potential breaks in the clouds and peeks of sun Monday
could boost temperatures into the upper 60s to lower 70s and
around 60 to lower 60s higher terrain. The best coverage of
showers and isolated to scattered thunderstorms will be along
and north of I-90 as the midlevel dry slot will build east of
our region and the upper deformation moisture and dynamics will
dominate. Still isolated showers and storms in southern areas,
too. Coverage of showers and isolated thunderstorms across the
entire region decreases Monday evening and night.

The mean northern stream upper trough axis builds just slightly
more east through Tuesday with more upper energy supporting more
development of showers and isolated thunderstorms, again mainly
along and north of I-90 but some isolated to scattered activity
in southern areas. Highs Tuesday in the mid 60s to near 70 with
some 50s in higher terrain.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Broad upper level troughing will be in place over the Great Lakes
and Northeast to open the long term period bringing cool and
unsettled weather through Wednesday. Troughing exits to the
northeast beginning Wednesday night, and is replaced by moderate
upper ridging and surface high pressure centered over the region,
yielding clear and dry conditions through Friday.

Tuesday night, somewhat elevated dewpoints in the mid to upper 40s
and partly to mostly cloudy skies effectively limit radiational
cooling, resulting in lows in the mid to upper 40s across the
region. Shower activity is possible due to cooler air aloft within
the upper trough, with the highest likelihood of showers over the
southwestern Adirondacks and central/western Mohawk Valley due to
the presence of lake-enhanced moisture. Showers persist into
Wednesday, with highs in the upper 40s to mid 50s in high terrain
and low to mid 60s at lower elevations, about 5-10F below average.
Winds increase out of the northwest, bringing in drier air with
dewpoints falling to the upper 30s to mid 40s.

PoPs diminish after Wednesday evening as heights rise aloft and
surface high pressure builds in from the west. Increasingly clear
skies and light winds at night allows for effective radiational
cooling and near to below average temperatures. Lows Wednesday night
range from the upper 30s in high terrain to mid 40s along the Hudson
River. Highs Thursday remain below average with upper 40s to mid 50s
in high terrain and upper 50s to mid 60s at lower elevations.
Thursday night brings more cold conditions with lows in the mid to
upper 30s in high terrain and upper 30s to low 40s elsewhere. Dry
weather likely continues into Friday with increased sun bringing
warmer temperatures to northern portions of the forecast area. Highs
will remain slightly below average with mid 50s to low 60s in high
terrain and low to mid 60s at lower elevations.

Beyond Friday, eyes turn toward the tropics as whatever remains of
Ian may move into the region. At this lead time, there is low
confidence about the track or any extratropical transition, but
chances for rain increase into next weekend.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
Through 06z/Mon...VFR conditions will start the TAF period until
at least 18z/Sun with mid-level clouds overhead. Bases will
start between 10-15 kft and lower closer to 5 kft by 18z/Sun.
Sunday afternoon and evening will consist of on-and-off showers
at all TAF sites with a few pockets of heavier showers also
possible. Maintained PROB30 groups for all sites to give a range
of when heavier showers could occur. A rumble of thunder is
also possible with KPOU the more favorable site at this time.
Cigs could trend into the MVFR range when heavier showers occur
along with vsbys in the IFR/MVFR range.

Shower activity should come to an end by 06z/Mon. There is then
an indication that low clouds and/or fog develop at most if not
all sites between 00z-06z/Mon. Low clouds are currently more
favored as there should still be a lingering low-level wind in
place. For now, have placed KGFL/KPSF in an IFR deck with
KALB/KPOU in MVFR.

Wind will remain light to calm overnight then be out of the
south to southeast at 6-12 kt on Sunday. Wind will become south
to southwest Sunday evening at 4-8 kt.


Outlook...

Sunday Night: High Operational Impact. Likely SHRA...TSRA.
Monday: Moderate Operational Impact. Breezy. Scattered SHRA...TSRA.
Monday Night: Low Operational Impact. NO SIG WX.
Tuesday: Moderate Operational Impact. Chance of SHRA.
Tuesday Night: Low Operational Impact. Slight Chance of SHRA.
Wednesday: Moderate Operational Impact. Chance of SHRA.
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: No Operational Impact. NO SIG WX.

&&

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

&&

$$
SYNOPSIS...NAS
NEAR TERM...IAA/NAS/JPV
SHORT TERM...NAS
LONG TERM...Picard
AVIATION...Rathbun

NWS ALY Office Area Forecast Discussion