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643
FXUS61 KALY 201731
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
131 PM EDT Thu Jun 20 2024

.SYNOPSIS...
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Hot and muggy weather will continue through the evening
hours, with showers and thunderstorms possible.  Some storms will be
severe and capable of producing damaging winds, hail and heavy
downpours.  While it will remain warn and humid on Friday, it won`t
be quite as hot as the past few days, with some additional showers
and thunderstorms possible, especially for southern areas. Continued
warm and sticky weather will continue into the weekend, with some
additional showers and thunderstorms possible each day, mainly in
the afternoon and evening hours.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
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As of 130 PM EDT...Severe Thunderstorm Watch #438 is in effect
for northern areas (Herkimer, Hamilton, Fulton, Warren, Saratoga
and Washington Counties in eastern New York and Bennington and
Windham Counties in southern Vermont) through 8 PM this evening.
The threat for damaging winds is the main threat, but hail and
heavy downpours will be possible as well.

SPC mesoanalysis shows MLCAPE of 1500-2500 J/kg in place over
the region thanks to the very warm and muggy air mass in place
over the region. Low level lapse rates are very steep due to the
strong heating, with values in the 7-8 C/km range, while mid
level lapse rates are weaker due to the warm temps aloft
(generally around 6 C/km). The best 0-6 km bulk shear remains
well north and west of the region. However, an approaching MCV
(currently just east of Lake Ontario) will help to allow for
storms to develop and some loose organization is possible into
small clusters as they pass west to east. Based on the latest
CAMs, northern areas will have the greatest threat for organized
storms, although some isolated cells are possible within the
pulse environment across the rest of the area. Even within the
isolated cells, locally damaging winds are possible due to
precip loading/wet microbursts thanks to the high PWATs in
place. The high PWATs, high freezing levels and effective cloud
processes could lead to some high rainfall rates, with hourly
rates over 1.50" per hour possible within the heaviest cells.
The recent dry weather should help prevent a widespread flash
flood threat, but can`t rule out some isolated issues,
especially if storms pass slowly across any urbanized areas.

The strong upper level ridge responsible for the recent hot
weather is starting to slowly shift southward. The center of 597
dm ridge is now centered over the northern mid Atlantic States,
although heights/temps aloft remain high over our area. 12z
KALY sounding still showed 500 mb heights around 596 dm, 850
hpa temps around 19 C and 925 hpa temps around 23 C. Expected
highs will be in the low to mid 90s in the valley areas with mid
to upper 80s in the high terrain. 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 to 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.

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, a partly cloudy sky and humid conditions
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.
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&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
**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. Patchy fog will also likely develop where
daytime rain took place.

Our boundaries from Friday hang around into Saturday and as our
anticyclone builds further south in to the TN/MS Valley, the
"ring of fire" around its northern periphery remains over
eastern NY and western New England. While temperatures will not
be hot as previous days, it will still be summer-like with high
temperatures reaching into the low to mid 80s for much of the
area. Dew points will also remain high enough to make it feel
humid. Heat index values will luckily finally be below heat
advisory criteria which will be a welcomed relief. Our region
remaining in the "ring of fire" combined with the boundaries
lingering overhead will allow for renewed convection during the
peak heating hours once again. Overall instability will be
weaker and the sfc boundaries will be less pronounced but with
embedded shortwaves still tracking aloft within the fast
westerly flow, strong shear may still be able to support some
stronger storms. Guidance suggests the boundary starts to lift
back northward as a warm front later in the afternoon which
could be a more favorable time for more widespread shower and
thunderstorm activity. We thus placed likely POPs Saturday
afternoon.

Showers and storms coverage weakens Saturday night as front
lifts north of the region. Just how far north the front reaches
remains uncertain and northern areas could still see
shower/storm activity should it not totally clear our area. Southerly
winds return in the wake of the boundary and guidance suggests
the warm sector that had finally left our region could make a
return. Temperatures remain warm in the mid to upper 60s and it
stay muggy.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
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Continued warm and humid conditions are expected to be in place
at the start of the long term period on Sunday. Valley areas
will be reaching into the upper 80s to low 90s once again, and
some heat index values could be approaching advisory criteria in
a few southern areas again. As a frontal boundary approaches
from the west, another round of showers and t-storms look to
occur during the afternoon and evening hours. With the expected
warm and humid conditions, there should be enough instability in
place, so will need to watch the threat for some stronger storms
once again as well. There are some timing differences in the
guidance regarding when the front moves through the area, as it
could be crossing on Sunday night or even early Monday, but
there should be enough forcing for an organized line or cluster
of storms on Sunday.

Will keep POPs in the chance range for Sunday night into Monday,
as the front and associated trough moves across the region. Once
the front clears the area, less humid air will be moving towards
the area, although this will be a fairly subtle change and temps
will still be above normal. By late Monday, skies will be
clearing out as well and the threat for precip will be lowering
as well.  Will still keep temps well into the 80s for Monday.

Quieter weather is expected for Tuesday with high pressure
nearby. While it should be rain-free, temps will still be rather
warm (valley areas in the mid to upper 80s) and it will be
fairly humid (dewpoints into the 60s) as well.

The next system will impact the region around Wednesday with
another round of showers and thunderstorms. In addition, temps
will be fairly warm once again with humid conditions. More
significant cooling and drying is expected towards Thursday
behind this system.
-- End Changed Discussion --

&&

.AVIATION /17Z THURSDAY THROUGH MONDAY/...
Through 12z Friday...Any lingering fog/mist burns off by 12z this
morning with just FEW to SCT mid and high clouds and prevailing VFR
conditions through at least noon today. This afternoon, showers and
storms are expected to develop. Have used tempo/prob30 groups to try
to hone in on the most likely time for showers/storms, but will
mention here that showers and storms are possible any time from
early afternoon through sunset this evening. If any storms move over
one of the terminals, then gusty winds and brief IFR vsby reductions
can be expected.

Showers and storms diminish tonight after sunset. Any areas that see
rain this afternoon/evening may see patchy fog overnight. Most
likely locations are GFL/PSF where fog has already been added to the
TAFs tonight. Will work to refine fog potential more with subsequent
TAF issuances.

Winds will be at 5-10 kt from the south/south west through most of
the day today, except will be more westerly at PSF. Winds diminish
to 5 kt or less after sunset tonight.

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.

&&

.CLIMATE...
Record High Temperatures...

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...

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...
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.

&&

$$

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