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335
FXUS61 KALY 200648
AFDALY

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

.SYNOPSIS...
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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.
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&&

.NEAR TERM /THROUGH TODAY/...
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**Heat Advisories remain in effect for all of eastern New York
 and western New England through 8 PM Thursday**

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.
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&&

.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
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**Heat Advisories continue through 8 PM Thursday for all of
 eastern New York and western New England**

Showers and thunderstorms will decrease in coverage and taper
off upon the loss of daytime heating tomorrow evening into
tomorrow night yielding a fairly dry overnight period. Much like
tonight, conditions will be muggy with low temperatures ranging
from the mid/upper 60s to low 70s.

By Friday morning, ridging aloft will have become relatively
flat, leading to flow becoming zonal. Geopotential height will
remain high, however, so while high temperatures Friday should
be cooler than Thursday, it will still be rather warm for mid-
June standards for most places. The other contributing factor
to this will be an approaching, weak cold front tracking from
northwest to southeast across the area throughout the day. This
will lead to rather variable highs across the region with
mid/upper 70s to low 80s at higher elevations and mid to upper
80s and even pockets of low 90s (lower Mid-Hudson Valley)
throughout most valley areas. At this time, heat indices look to
be highest in the Hudson Valley where low to mid 90s are
possible. However, with uncertainties still in existence
pertaining to the timing of the front, we have chosen to hold
off on any additional heat advisories for these areas. It is
certainly possible that once confidence increases, additional
products could be necessary, but will certainly be much less
widespread than the past several days.

With the passage of the front, additional rounds of showers and
thunderstorms are expected across eastern New York and western
New England throughout the day Friday. At this time, the
greatest instability lies south and west of the Capital District
where the greatest heating will likely be allowed to take place
ahead of the front. Here, a Marginal Risk for severe
thunderstorms has been issued by the SPC. Strong to isolated
storms are again likely to be isolated in terms of coverage.
Showers and possibly some embedded rumbles of thunder persist
into Friday night as the front becomes stalled just south of the
region along the NY/PA border. Low temperatures will fair a bit
cooler than recent days with upper 50s expected in the Southwest
Adirondacks and Southern Greens and low to upper 60s elsewhere.
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&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
The long term period generally looks to start unsettled with the
chance for showers and thunderstorms Saturday through Monday.
The aforementioned stalled boundary looks to linger just south
of the region Saturday, causing the chance for additional rounds
of showers and thunderstorms throughout the day. High
temperatures will be several degrees cooler Saturday, though
still relatively warm, with mid/upper 70s to mid 80s anticipated
across the region.

Sunday, the stalled boundary lifts north and east across the
area as a warm front as a surface low traverses southeast
Ontario into southern Quebec and a positively- tilted upper-
level trough begins to dig into the region. With a trailing cold
front remaining well upstream, a warm sector will be created
across the region, such that more showers and thunderstorms will
be likely. This is the period to watch as some storms could
become strong to severe with the anticipation of instability
increases intersecting zones of higher shear. Will continue to
monitor this period over the coming days for severe weather
potential. Highs Sunday will increase to the upper 70s/low 80s
at higher elevations to mid/upper 80s and possibly some low 90s
in valley areas.

Showers and thunderstorm chances continue into Monday as the
upper-level trough swings through the region in tandem with the
cold front. Directly in its wake, upper ridging builds in to
force the return to dry conditions Tuesday through the remainder
of the long term period. This will, however, mean the return to
hot weather as temperatures rise back into widespread mid/upper
80s to low 90s by Wednesday.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
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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...

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

.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...
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CT...Heat Advisory until 8 PM EDT this evening for CTZ001-013.
NY...Heat Advisory until 8 PM EDT this evening for NYZ032-033-
     038>043-047>054-058>061-063>066-082>084.
MA...Heat Advisory until 8 PM EDT this evening for MAZ001-025.
VT...Heat Advisory until 8 PM EDT this evening for VTZ013>015.
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&&

$$

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