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766
FXUS61 KALY 200926
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
526 AM EDT Thu Jun 20 2024

.SYNOPSIS...
Our stretch of hot and humid weather continues today with
scattered areas of showers and thunderstorms this afternoon.
Some storms may become strong producing damaging winds gusts,
heavy downpours, and frequent lightning. We remain very warm and
humid Friday through the weekend but not quite as hot as
previous days. Areas of showers and thunderstorms redevelop
each afternoon with potential for more widespread rain and
stronger storms on Sunday as a cold front approaches.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
**Heat Advisories remain in effect for all of eastern New York
 and western New England through 8 PM today. The Heat Advisory
 continues for the mid- Hudson Valley and southern Litchfield
 County through 8PM Friday.**

A muggy and warm night continues across eastern NY and western
New England tonight with many areas still in the upper 60s to
upper 70s. Regional radar shows a few areas of rain showers and
embedded storms in central NY tracking eastward but with GOES16
IR showing warming cloud tops, these showers will likely weaken
as they reach our western Mohawk Valley and southern Adirondack
areas. Otherwise, we note an MCS in southern Ontario tracking
eastward but again, IR shows warming cloud tops so this complex
will likely continue diminishing. A more impressive line of rain
and storms are quickly developing off Lake Ontario and
progressing towards the Tug Hill. This will need to monitored
over the coming hours as IR shows cloud tops cooling quickly.
CAMs are not handling current coverage of showers/storms well
but based on radar and satellite trends, slight and chance POPs
in western zones through 12 UTC seems reasonable. Will adjusted
as needed over the coming hours.

Otherwise, expecting a third day of hot and humid weather today
as our large anticyclone with central heights around 597dam
gradually pushes southward into the mid-Atlantic. With slightly faster
zonal flow around the periphery of the ridge sliding south into
more of eastern NY and western New England, we will be in a more
favorable corridor that will likely support afternoon shower and
thunderstorms. Our environment of 850hPa isotherms around
18-19C, mixing up to around 800-850hPa, isolated storm coverage and
a thicker cirrus canopy the past few days has resulted in
mainly low to mid 90s highs and upper 80s in the higher terrain.
Similar conditions are expected today except with higher shower
and storm coverage so continue to show low to mid 90s for highs
in the valley areas with mid to upper 80s in the high terrain.
We limited mid-90s to the mid- Hudson Valley where shower/storm
coverage should be less. Combination of temperatures in the
80s/90s and high dew points in the low 70s will once again
support dangerous heat index values reaching 95 - 100F.
Technically we have lower heat index values in the southern
Adirondacks and southern Greens but given this is the third day
of hot/humid weather and that most of these areas do not have
air conditioning, we maintained heat advisory headlines.

A sfc trough tracking southward towards our region midday into
the afternoon will provide a focus for afternoon shower and
thunderstorm development. In addition, embedded shortwaves
within the zonal flow aloft will also enhance forcing for
ascent. The hot/humid environment will easily support moderate
to high instability values ranging 1.5 - 2.5k J/kg so once
convective initiation begins, updrafts will likely quickly
strengthen. Taller storms will present damaging wind concerns
as DCAPE values reach >500J/kg. Given weak shear with 0-6km
shear values only around 20kt, storms should mainly be pulse-
type but can grow into storm clusters from outflow
boundaries/cold pools. High equilibrium levels >35kft will also
present high NCAPE and hail cape values which local research
shows supports frequent lightning as well. High PWATs around 2"
and high freezing levels >10kft means we will see efficient warm
rain processes and storms producing heavy downpours. Weak
steering flow aloft can result in some localized poor drainage
flooding, especially if storms persist over a given area.
Guidance and CAMs focus convection mainly around I-90 northward
where the best "ridge roller" environment should set-up so
placed likely POPs here and trended POPs to just chance in the
mid- Hudson Valley and NW CT. SPC maintained its "slight risk"
today with damaging winds the primary hazard. While the storm
coverage is not as widespread as we typically see with slight
risk type of days, the high instability will allow updrafts that
develop to quickly grow towards severe limits and with
increased forcing for ascent in place today, storm coverage
should be greater than we have seen in previous days.

Showers and thunderstorms diminish in coverage this evening
with the loss of daytime heating but a few isolated showers and
storms likely linger overnight as the sfc trough stalls over
the region. Otherwise, continued cloud coverage will keep
temperatures warm and it will stay muggy, especially in areas
that experience rainfall, once again overnight with
temperatures only dropping into the upper 60s to low 70s. Fog
should develop shortly after sunset in areas that experience
rain given the moist environment.
-- End Changed Discussion --

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
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**Heat Advisories continue for the mid-Hudson Valley and
 southern Litchfield County through 8PM Friday**

We remain within the northern periphery of our broad ~595dm
anticyclone Friday into Saturday with the conveyor belt of
increasingly stronger zonal/westerly flow and thus stronger
shear developing over eastern NY and western New England each
day. For Friday, the sfc trough from Thursday likely lingers
just south of Interstate 90 with a cold front gradually
approaching from the International border. Areas south of the
sfc trough, mainly the mid-Hudson Valley and Litchfield County,
will remain in the very warm and humid air mass with
temperatures likely rising back into the low to mid 90s. Given
continued high humidity, heat index values in these southern
zones should exceed heat advisory criteria reaching 95 - 100F
for a fourth day and thus we have extended our heat advisory for
Dutchess, eastern Ulster and southern Litchfield County through
8 PM Friday. We considered added in northern Litchfield and
western Ulster but current thinking is heat index values will be
a few degrees shy of the 95F heat advisory criteria and thus
did not included these zones. The day shift and reevaluate and
expanded the advisory if needed. The rest of the region will
still very warm and humid but high temperatures should only
reach into the mid to upper 80s and although it still will be
quite humid, the lower temperatures will keep heat index values
under the 95F threshold.

Given the lingering sfc trough near or just south of I-90 and
the additional forcing from the incoming cold front pressing
southward, isolated to scattered showers and thunderstorms will
likely quickly initiate once we reach the diurnal peak heating
hours by late morning with storm coverage growing through much
of the afternoon. Sfc instability will remain sufficiently high
1 - 2k J/kg and stronger westerly flow aloft will contribute to
higher deep layer shear ranging 25 - 35kts. Damaging winds
again are the primary concern with pulse type storms developing
along the sfc trough capable of evolving into line or bowing
segments thanks to stronger shear values. SPC has expanded it
marginal risk for severe weather from the I-90 corridor
southward through the mid-Hudson Valley and Berkshire/Litchfield
County where the higher instability and sfc trough should
overlap. However, the cold front pushing southward from
northern NY later in the afternoon will serve as a secondary
focus for organized convection for areas north of I-90 and the
stronger shear will help compensate for the somewhat weaker
instability. Thus, strong to severe storms including line or
bowing segment capable of damaging winds are possible even for
areas north of I-90. Heavy downpours are possible from
thunderstorms throughout the region as well given PWATs hovering
around 2" and efficient warm processes still in place.

Showers and storms gradually weaken in coverage and strength
Friday night but with boundaries lingering overhead, we
maintained chance POPs overnight. Expect another muggy and warm
night thanks to the lingering showers/isolated storms with
overnight lows only dropping into the mid to upper 60s. Areas in
the southern Adirondacks and southern Greens should turn a
little cooler as winds shift to the north-northeast in the wake
of the cold front.
-- End Changed Discussion --

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
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Long term begins at 12z Sunday with a potent upper shortwave and
associated surface low located over the northern Great Lakes
region. The surface low deepens as these features track to the
eat/northeast Sunday. The system`s warm front will have lifted
north of our region by Sunday morning, placing our region in the
warm sector. As the pressure gradient strengthens, S/SW winds
increase and help to advect warm moist air into our region.
Exact highs are somewhat uncertain due to uncertainty in how
much cloud cover we see, but the current forecast is for highs
in the low 90s for portions of the Mid Hudson Valley with dew
upper 80s for the remainder of our valley locations with dew
points in the upper 60s and low 70s. Accordingly, heat indices
are currently forecast to reach low-end heat advisory criteria.
If forecast confidence in these heat index values increases over
the coming days, then additional heat advisories may be needed.


The system`s cold front will track through our region Sunday night
or Monday, and a pre-frontal trough will cross the region late
SUnday afternoon or evening ahead of the main cold front. With ample
instability and the LLJ and flow aloft both strengthening, there may
be enough overlap of instability and shear for some storms to be
strong to severe. Coverage and strength of storms will ultimately
depend on the timing of the pre-frontal trough relative to peak
heating. Best chance for strong to severe storms is on Sunday, but a
slower cold frontal passage may leave the window open for a few
stronger storms in western New England on Monday as well. Forecast
confidence on the timing of the cold front remains on the lower
side, but we should get a better idea over the next couple of days.

We see briefly cooler and drier weather Tuesday behind the front as
high pressure builds in from the southwest, but this high will
quickly slide to our east putting our region in a warmer S/SW flow
regime again for Wednesday. Then, Wednesday or Thursday, another
cold frontal passage may bring additional shower and thunderstorm
chances with cooler weather returning towards the end of the week.
However, the CPC still expected temperatures for days 8 to 14 to
average above normal with near normal precip for that same
timeframe.
-- End Changed Discussion --

&&

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
Through 06z Friday...Fog/mist has already formed at GFL with IFR
vsbys there, with VFR conditions at all other TAF sites. Expecting
patchy fog to remain at GFL through around sunrise, and will handle
with a tempo group. ALB/POU should remain VFR through the night, but
will include a tempo group for some fog/mist at PSF for a couple hrs
right before sunrise. Confidence in fog at PSF is not as high so
will just mention low-end MVFR vsbys for now, but IFR or lower vsbys
are possible if fog forms.

FOg lifts quickly this morning with just some passing mid and high
clouds and VFR conditions through the morning. However, by early
afternoon, scattered showers and thunderstorms will likely develop.
Have expanded the prob30 groups to 3 hrs at all TAF sites to try to
better capture the window for thunderstorms, but will not that
thunderstorms remain possible (around a 30% chance)from 18z through
at least sunset at ALB/GFL/PSF. Lower chances for a storm at POU, so
will not mention thunder here just yet. Showers should slowly
diminish after sunset. Will include prevailing VFR conditions for
now, but if any of the TAF sites see a heavier shower/storm this
afternoon then fog/mist would be possible after sunset.

Winds should be light and variable tonight, increasing to 5-10 kt
from the south/southwest this morning, lasting through sunset
tonight before becoming light and variable again. Gusty winds are
possible with any thunderstorms this afternoon.

Outlook...

Friday Night: Moderate Operational Impact. Scattered SHRA...TSRA.
Saturday: High Operational Impact. Numerous SHRA...TSRA.
Saturday Night: Moderate Operational Impact. Scattered SHRA...TSRA.
Sunday: High Operational Impact. Likely SHRA...TSRA.
Sunday Night: High Operational Impact. Likely SHRA...TSRA.
Monday: Moderate Operational Impact. Breezy. Chance of SHRA...TSRA.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
-- End Changed Discussion --

&&

.CLIMATE...
Record High Temperatures...

Wednesday, June 19:
Albany - 94 (1995)
Glens Falls - 97 (1995)
Poughkeepsie - 92 (1941, 1943, 1993, 2016)

Thursday, June 20:
Albany - 97 (1953)
Glens Falls - 97 (1923)
Poughkeepsie - 96 (2012)

Friday, June 21:
Albany - 97 (1938)
Glens Falls - 96 (2012)
Poughkeepsie - 97 (1949)

Record High Minimum Temperatures...

Wednesday, June 19:
Albany - 71 (1976)
Glens Falls - 67 (1905, 1949, 1976, 2017)
Poughkeepsie - 73 (1993)

Thursday, June 20:
Albany - 73 (1893)
Glens Falls - 68 (1964)
Poughkeepsie - 71 (1931)

Friday, June 21:
Albany - 72 (1923)
Glens Falls - 71 (1953)
Poughkeepsie - 73 (1931)

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Heat Advisory until 8 PM EDT this evening for CTZ001.
     Heat Advisory until 8 PM EDT Friday for CTZ013.
NY...Heat Advisory until 8 PM EDT this evening for NYZ032-033-
     038>043-047>054-058>061-063-082>084.
     Heat Advisory until 8 PM EDT Friday for NYZ064>066.
MA...Heat Advisory until 8 PM EDT this evening for MAZ001-025.
VT...Heat Advisory until 8 PM EDT this evening for VTZ013>015.
-- End Changed Discussion --

&&

$$

SYNOPSIS...Speciale
NEAR TERM...Speciale
SHORT TERM...Speciale
LONG TERM...Main
AVIATION...Main
CLIMATE...Picard/Rathbun