-- Discussion containing changed information from previous version are highlighted. --
938
FXUS61 KALY 141415
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
1015 AM EDT Fri Jun 14 2024

.SYNOPSIS...
A swift-moving cold front will track through the region
today, bringing showers and thunderstorms, some of which could be
strong to severe south and east of the Capital District. High
pressure behind the front will then ensure a beautiful, dry weekend
before a significant warm up is expected next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
.UPDATE...As of 10 AM EDT, band of mainly light rain showers
continues to translate east/southeast from southern VT into the
Capital Region and south into the eastern Catskills. This band
should continue eastward over the next 1-2 hours, and may weaken
slightly.

Latest SPC Mesoanalysis depicts MU CAPES of 250-500 J/kg across
the region, with pockets of slightly higher values across the
SW Adirondacks/Mohawk Valley where some breaks in the clouds are
occurring. There is considerable low level CINH along and east
of the Hudson River due to the extensive mid level cloud cover
and associated showers.

We expect the current band of showers to continue shifting east
of the region by late morning. In its wake, we expect some
clearing to develop. This should allow instability to increase
across the region, however there will also be drier air from
aloft mixing downward (noted on upstream 12Z/BUF sounding)
which should decrease instability early this afternoon for areas
near and north of I-90. The leading edge of this slightly drier
air should be developing close to the Capital Region, southern
VT and NE Catskills early this afternoon before slowly shifting
southeast. Areas to the south/east of this low level moisture
gradient will be more susceptible to greater instability, along
with greater forcing from weak shortwave/height falls
approaching from the west.

So, greatest threat for strong to perhaps a few severe
thunderstorms will be mainly south/east of Albany this
afternoon, particularly across the SE Catskills, mid Hudson
Valley, southern/central Taconics and NW CT into the Berkshires.
Strong wind gusts and some hail will be possible with any
stronger storms that develop, especially if they form into small
clusters/bowing segments.

Farther north and west, although isolated showers/thunderstorms
may develop closer to the actual cold front approaching from the
northwest, a deeper layer of dry air and reduced instability
should keep coverage much more limited.

Afternoon temps may spike into the lower/mid 80s in some areas
once some clearing develops across the Capital Region, upper
Hudson Valley and eastern Mohawk Valley, with generally upper
70s to lower 80s expected elsewhere.

PREVIOUS UPDATE...As of 7 AM EDT...Aforementioned line of
showers has pretty much broken apart outside of some scattered
showers and sprinkles in southern Vermont. Today`s cold front
has reached northwest New York and will continue to track south
and east throughout the day. Only minor adjustments were needed
with this update to keep consistency with latest obs and trends.
Otherwise, the previous forecast remains in good shape. See the
previous discussion below for additional details pertaining to
today`s forecast.

.PREVIOUS DISCUSSION...
A band of showers continues to progress further south and east
through the Southwest Adirondacks and Mohawk Valley this morning
in association with a pre-frontal trough rotating through the
region ahead of a cool frontal boundary currently located along
the International border. Embedded pulses of lightning have been
previously noted within this line as it has crossed through
central New York, but with little to no instability within our
CWA, have weakened to mere light to moderate rain showers.

The pre-frontal trough has dug further south and east into the
region than previous thinking suggested, allowing showers to be
maintained further south and east. And while the KENX radar
seems to show a gradual weakening trend, a few showers cannot be
ruled out as far south as the Capital District this morning and
perhaps as far east as southern Vermont. Latest CAMs indicate
this line falling completely apart before it reaches areas south
of Albany as the upper disturbance begins to fill to the north
and east with its parent surface low tracking further north,
deeper into Quebec. However, with the axis of the upper impulse
noted through SPC Mesoanalysis as being more or less overhead,
it is possible that sufficient forcing could sustain light
showers as far south as the Mid-Hudson Valley and into the
Taconics despite its increased distance from the boundary. Once
this batch of showers dissipates later this morning, dry
conditions will be reinforced briefly as the cold front
continues to encroach further from the northwest. Additional
rounds of showers and thunderstorms can then be expected this
afternoon along its southeast track through eastern New York and
western New England.

Likely due to the ongoing convection this morning, latest CAMs
show some disagreement in their solutions to convection this
afternoon. The main source of uncertainty seems to be the exact
location of initiation this afternoon ahead of the front and
the resultant spatial extent of convection. Because of the
showers and few embedded thunderstorms that tracked through the
Southwest Adirondacks late this past evening and this morning, a
sufficient loss of energy will likely force additional
development further south towards the Capital District. That`s
not to say that a few showers and an isolated rumble of thunder
won`t be possible in this area later this morning as the front
approaches, but this paired with the more favored forcing to the
south and east certainly shifts focus away from this area.

The primary focus for convective re-development ahead of and
along the front rests primarily within the eastern Mohawk Valley
and greater Capital District where upper-level forcing continues
to be favored. With a shortwave trough closely accompanying the
front providing enhanced PVA along its leading edge and the
right entrance region of a weakening, though still sufficient,
upper-level jet streak, large scale ascent will be favored from
the aforementioned areas south and east. Breaks of sun ahead of
the fropa during peak heating hours will help SBCAPE rise
towards 1000-1500 J/kg with pockets potentially closer to 2000
J/kg within the Mid-Hudson Valley, Southern Berkshires and
Litchfield County. Higher regions of instability will intersect
deep-layer shear near 30-40 kt with marginal mid-level lapse
rates between 6-7 C/km and high low-level lapse rates increasing
to 8-9 C/km by this afternoon. Initial storm motion oriented
nearly perpendicular to the progression of the boundary will
likely lead to discrete storm modes, though a gradual congealing
into a linear segment is likely given backing flow.

All that said, current thinking points towards discrete cells
developing likely within the eastern Mohawk Valley and greater
Capital District early this afternoon with a gradual increase
in spatial coverage as the front continues to track further
south and east. Later this afternoon, as the axis of the upper
shortwave nears, spatial coverage of storms will likely increase
within the Mid-Hudson Valley, becoming more of a linear segment
that tracks south and east into western New England
(specifically the Southern Berkshires and Litchfield County)
through this evening. It is in these areas that the likelihood
of severe thunderstorms increases with a focus on strong to
potentially damaging winds and possible large hail as the main
threats. Thermal profiles indicate DCAPE on the order of
500-1000 J/kg with mean flow near 25 kt and low-level dry air
that could promote stronger wind gusts. Additionally, higher
cloud-layer shear could promote longer sustainment of
hailstones, leading to larger growth. However, with fairly moist
mid-levels and warm antecedent environments, it is very
possible that hail could undergo a good deal of melting before
reaching the ground. But certainly hail sizes reaching 1" in
diameter or potentially larger cannot be ruled out. The final
concern with these storms will be heavy downpours. PWATs look to
increase to about 1.5" throughout the region and stronger
forcing will aid in thunderstorms producing heavy rain rates at
times. Ponding of water in poor drainage and urban areas is
definitely possible and an isolated flash flood cannot be ruled
out especially in prone areas, but relatively dry antecedent
conditions limit the concern for widespread hydro issues.

High temperatures today will be fairly variable given the
anticipated conditions. Anticipate upper 60s to low 70s at
higher elevations with mid/upper 70s to low 80s in valley areas.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
Showers and thunderstorms look to taper off quickly this evening
upon the full passage of cold front and the loss of daytime
heating. In the wake of the front and the full rotation of the
upper shortwave through the region, Canadian high pressure
builds in from northwest to southeast to reinforce dry
conditions for the weekend. Low temperatures tonight will range
from the low to upper 50s with pockets of upper 40s above 1500
ft.

A newly enforced, cooler airmass will bring highs down to the
mid/upper 60s to mid/upper 70s for Saturday as upper-level
ridging amplifies across the region. Saturday night will be
quite chilly by June standards with lows widely in the 40s with
upper 30s in the SW Adirondacks. Sunday will then begin a
warming period as the ridge axis builds in overhead. Anticipate
highs in the low to upper 70s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A weak upper impulse it expected to track through northern areas
Sunday night into Monday with just an isolated shower or
thunderstorm, mainly in the southern Adirondacks. Once this upper
impulse exits, upper ridging will build into the eastern U.S. and
will amplify.

There is an increasing consensus from sources of guidance/ensembles
that the very strong upper ridging will be centered in the southern
Appalachians to OH Valley by Tuesday and overhead in the
northeastern U.S. by Wednesday. Then, there are disagreements in
sources of guidance/ensembles whether the upper ridging builds back
south or if it builds east and offshore by Thursday. Either way,
extreme heat along with oppressive humidity is likely Tuesday
through Thursday. Some record highs are possible. Will some areas,
including Albany, reach 100 degrees at some point Tuesday through
Thursday? It is not likely but not out of the question.

There are hints of some isolated diurnal thunderstorms each
afternoon but strong midlevel and upper level capping with the
strong upper ridging will limit those possibilities. Any convective
clouds or cloud debris could filter the sun just enough to prevent
maximum heat. The 500 hPa heights are forecasted to be extremely
anomalously high, increasing confidence in the extreme heat over the
region.

High temperatures Monday well into the 80s with around 80 higher
terrain. Then, the extreme heat arrives. High temperatures Tuesday
in the lower to mid 90s with upper 80s higher terrain. It may feel
like around 100 degrees in some areas due to the humidity. Highs
Wednesday and Thursday in the mid to upper 90s with around 90 in
higher terrain. It will feel like 100 or more in some areas. There
will not be much relief at night as lows Tuesday night and Wednesday
night will be in the upper 60s to lower 70s. There are signals of
some gradual relief and cooler temperatures at the end of next
week.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
Line of weakening showers around KALB for the next hour or two.
Then, a new line of showers and scattered thunderstorms is expected to
develop after about 15Z near or just south and east of KALB. Other
showers will form around KGFL and including showers with MVFR
conditions between about 15Z-19Z at KGFL and KALB. As the
thunderstorms develop in the afternoon, including a brief period of
thunder at KALB between 19Z-20Z, that will likely be shifted either
earlier or later, depending on the actual observed storms later
today.

The best coverage and duration of showers and storms is expected at
KPOU and KPSF, where thunderstorms are included between about 20Z-
23Z with MVFR conditions. Some brief bursts to IFR are possible in
the heaviest rain but too brief to include in TAFs. By 22Z-24Z, rain
exits KALB and KGFL, while some showers could linger at KPOU and
KPSF until around 02Z-03Z. VFR conditions expected once the showers
and storms exit this evening.

Steady south winds through this morning at 10 Kt or less, with a
gust around 15 Kt at times at KALB and KPSF. Thunderstorms could
have gusts to 35 Kt this afternoon. Winds shift to west and
northwest this afternoon at 10 Kt or less and then to north at less
than 10 Kt this evening through tonight.


Outlook...

Saturday Night: No Operational Impact. NO SIG WX.
Sunday: No Operational Impact. NO SIG WX.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: No Operational Impact. NO SIG WX.

&&

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

&&

$$

SYNOPSIS...Gant
NEAR TERM...Gant/KL
SHORT TERM...Gant
LONG TERM...NAS
AVIATION...KL/NAS