272
FXUS61 KALY 081435
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
1035 AM EDT Wed May 8 2024

.SYNOPSIS...
A warm front will bring some showers and isolated to scattered
thunderstorms this morning. A prefrontal disturbance and a cold
front will bring additional showers and thunderstorms in the
afternoon and early evening with a few on the stronger side.
Seasonable temperatures return on Thursday, as clouds increase
and rain moves back in from the south in the afternoon ahead of
a warm front and a low pressure system in the Ohio Valley with
unsettled weather and cooler temps continuing into Friday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 10:35 AM EDT...Convection from earlier this morning has
moved off to the north and east of the region. Other than a
couple lingering showers, most of the region is now dry and
should remain dry through the next couple hours. Surface warm
front is currently draped from the southwestern tip of Herkimer
County through the Mid Hudson Valley and Litchfield County, with
a surface low east of Lake Ontario. South of the warm front,
temperatures are well into the 60s, while areas north of the
warm front remain socked in with clouds and temperatures in the
upper 40s to mid 50s. A pre-frontal trough and associated dew
point boundary are currently located in central NY and will
track through our region this afternoon.

As the pre-frontal trough tracks through, low-level convergence
along the wind shift boundary will provide enough forcing for
ascent to spark a few showers and thunderstorms. With the best
forcing to our north with an approaching shortwave, showers and
thunderstorms will be isolated to scattered in nature. However,
SPC mesoanalysis and CAMs suggest that there will be an overlap
of SBCAPE of over 1000 J/kg as mid-level lapse rates steepen to
over 7C/km and deep-layer shear of 50-60 kt. This will allow for
a couple storms to be strong to severe, with the greatest
threats being damaging wind gusts and hail. Greatest threat area
will be for areas along and south of the warm front, which
includes the eastern Catskills, Mid Hudson Valley, and western
CT and MA. Timing of any strong to severe storms looks to be
from around noon through 4 pm. Behind the pre-frontal trough,
drier air is advected into the region, which when combined with
the loss of daytime heating should allow for instability to
decrease and limit the overall severe threat. Another round of
showers and a few thunderstorms is expected late this afternoon
and evening across the Adirondacks and Mohawk Valley, but
waning instability here should limit the severe threat.

Overall, this update includes minor adjustments to temps, dew
points, and PoPs to better reflect current position of the warm
front, but the overall forecast message remains on track from
the previous forecast. Please see below for more details on the
threat for severe weather today...

.Previous...The mid level jet will be in the 50-70 KT range
enhancing the 0-6 km deep shear through this morning. The
threat for strong to severe thunderstorms continues to be
somewhat nebulous with the best shear out of phase with the
better instability. A pre-frontal sfc trough will be moving
towards and across eastern NY and western New England in the
late morning/early pm. The 00Z HREFS indicate mean SBCAPEs in
the 750-1250 J/kg range with the values closer to 1000 J/kg in
the Hudson River Valley or mainly from the Capital Region south
and east. The deep shear is strong and top heavy with the
stronger winds in the 700-500 hPa layer. Mid level lapse rates
will be in the 6.5-7C/km range based on the NAM/CMC/ECMWF from
ALY south and east. We added enhanced wording for small hail and
gusty winds south and east of the Capital Region over the
southeast Catskills, mid Hudson River Valley, southern and
central Taconics, Berkshires and NW CT. A few of the storms may
be marginally severe with 1" hail or damaging winds. SPC
continues a Marginal Risk for the entire forecast area.

Temps should rise above normal in the warm sector and due to
some downsloping off the Helderbergs/southern Dacks/eastern
Catskills we could see max temps spike with the southwest/west
flow with the prefrontal trough. Max temps were raised in the
the mid 70s to around 80F in the valleys with 60s to lower 70s
over the higher terrain. The lower 80s will be near KPOU.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
Tonight...The main cold front approaches from the west late in
the afternoon into the early evening. Additional scattered
showers or isolated to scattered thunderstorms will form with
less instability. These storms are not expected to be severe.
The best chance of showers activity will be from the Capital
Region north and west. Cold advection will occur in the wake of
the front with lows in the 40s, except lower 50s from the
Capital District south and east. We did not add any patchy fog
yet due to partly to mostly cloudy conditions and a west to
northwest breeze overnight.

Thursday...the mid level flow becomes zonal over the Northeast
in the wake of the first system. A brief break in the pcpn
action is possible in the morning, but then the old cold front
begins to lift northward again ahead of the next wave ejecting
from the Midwest into the Ohio Valley. The isentropic lift
increases again for a period of showers/rain initially south of
I-90 in the late morning/early pm but then expanding northward.
This is all occurring ahead of a positively tilted mid and
upper level trough over southeast Canada, the Great Lakes Region
and Midwest. Temps will not be able to recover from normal
seasonal readings due to thickening and lowering clouds. Highs
will be in the mid and upper 60s in the lower elevations with
50s to lower 60s over the hills and mtns.

Thursday Night through Friday night...A sfc cyclone slides east
from the Mid Atlantic Region/NJ Coast Thu night with scattered
showers persisting due to the upper level low nearby. In the
dank air mass lows will be in the 40s with some upper 30s over
the southern Greens/southern Dacks.

Yet another short-wave impulse rotating around the broader mid
and upper level trough is expected to bring another period of
rainfall on Friday. The differential cyclonic vorticity
advection will help focus the rain during the day and it will
taper in the evening. The coolest day of the week is expected
with cloudy skies and a stratiform cooled atmosphere with highs
a good 10 degrees below normal with mid 40s and mid/upper 50s
over eastern NY and western New England. The rainfall may cause
some ponding of water in a few spots. As the column cools
overnight a chilly rain will taper. A few wet snow flakes may
occur over the southern Greens. Lows will be in the mid 30s to
mid 40s.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Unsettled conditions with below normal temperatures looks to
dominate much of the long term period, as upper level troughing
persists across the Great Lakes/northeast region. Upper level
disturbances passing through this trough will bring enhanced chances
for showers, which currently looks best on Sunday, however
isolated/scattered showers will be possible Saturday as well.

The upper level trough will gradually shift east of the region early
next week, however an upper level disturbance and associated frontal
system looks to track across the region late Monday or early Tuesday
with additional rain showers possible.

High temperatures will only reach the mid 50s to lower 60s Saturday-
Sunday, although could be even cooler if widespread showers occur.
Overnight lows mainly in the 40s, with some 30s possible across
higher elevations. Gradual warming Monday-Tuesday, with highs
reaching the 60s for many areas Monday, and mid 60s to lower 70s
Tuesday. Overnight lows in the 40s for Monday and Tuesday morning,
although some 30s will be possible across the southern Adirondacks.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
A warm front will approach from the west this morning, followed
by a cold front passing through from the northwest late
this afternoon.

Area of showers and embedded thunderstorms will continue
tracking east across the TAF sites through around 13Z-14Z/Wed. A
period of MVFR/brief IFR Vsbys and MVFR Cigs will be possible as
this passes. Behind these showers/thunderstorms, a period of
MVFR Cigs are expected with only isolated showers. A few
showers/thunderstorms may then develop between 16Z-19Z/Wed as a
wind shift line passes eastward. Coverage will be isolated at
best, so have not included mention in this set of TAFs, however
AMDs will be issued should thunderstorms develop and potentially
impact a TAF sites.

VFR conditions are then expected this afternoon and early
evening. Scattered showers may then develop and affect KGFL with
a cold front. MVFR Cigs are then expected to develop at KGFL,
KALB and KPSF later this evening behind the cold front.

Light/variable winds will become south to southwest at 5-10 KT
by mid morning, then will shift into the west after 19Z/Wed and
increase to 10-15 KT with some gusts up to 25 KT, strongest at
KALB and KPSF. Winds will become west to northwest and decrease
to 8-12 KT toward and after 00Z/Thu.

Winds will be stronger, and variable in direction in and near
any thunderstorms.

Outlook...

Thursday Night: High Operational Impact. Likely SHRA.
Friday: High Operational Impact. Likely SHRA...RA.
Friday Night: Moderate Operational Impact. Chance of SHRA.
Saturday: Moderate Operational Impact. Chance of SHRA.
Saturday Night: Moderate Operational Impact. Chance of SHRA.
Sunday: High Operational Impact. Likely SHRA.
Sunday Night: Low Operational Impact. Slight Chance of SHRA.
Monday: Moderate Operational Impact. Chance of SHRA.

&&

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

&&

$$

SYNOPSIS...Wasula
NEAR TERM...Main/Wasula
SHORT TERM...Wasula
LONG TERM...KL
AVIATION...KL