-- Discussion containing changed information from previous version are highlighted. --
599
FXUS61 KALY 220204
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
1004 PM EDT Tue May 21 2024

.SYNOPSIS...
It will remain warm and muggy through Wednesday, with
some scattered showers and thunderstorms during the afternoon and
evening hours.  A cold front on Thursday will bring some additional
showers and storms, especially for areas south and east of Albany.
Cooler and less humid air is expected behind the front on Friday
with dry weather. Some additional showers are possible through the
holiday weekend.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
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.UPDATE...As of 1000 PM EDT...One last line of thunderstorms is
traversing the Upper Hudson Valley with cold pool showers
trailing close behind it. KENX radar shows a weak gust
front/outflow boundary that has moved ahead of the main line,
leading to the weakening of the storms overall. However, some
pulses of lightning still exist so kept slight chance of thunder
in the forecast. An additional couple of showers are present in
Herkimer County, but no lightning is embedded within these. All
shower/thunderstorm activity should conclude within the next few
hours.

Overall, the forecast remains in good track. Minor adjustments
were made to temperatures, PoPs and sky coverage to reflect
current obs and latest trends. See the previous discussion below
for additional details.

.PREVIOUS DISCUSSION...
As of 355 PM EDT...Upper level ridge axis continues to shift
southeast of the area and now extends from the mid Atlantic
northeast offshore into the western Atlantic Ocean to the east
of eastern New England. Meanwhile, a compact upper level
disturbance (probably a leftover MCV) is moving along the
International Border across the North Country of northern New
York. This feature is running along the northern fringe of the
ridging. At the surface, high pressure is now located offshore
New England, keeping a moist and mild southerly flow in place
over the area.

SPC Mesoanalysis shows around 500-1500 J/kg of MLCAPE over the
area. 0-6 km bulk shear is only around 20-30 kts, with the
better values along and just north of the area closer to the
passing disturbance. While mid level lapse rates are rather weak
(around 6 C/km), low level lapse rates are high due to the
strong solar insolation today, allowing for decent DCAPE (around
800-1200 J/kg).

Some scattered storms developed this afternoon across the Lake
George and Glens Falls area, as well as across parts of the
Capital Region. Some gusty winds have been occurring as these
storms collapse thanks to the steep low level lapse rates, with
some reported gusts of 30-50 mph. Radar imagery would suggest
some hail has been occurring within these storms as well,
although hailstones are likely melting somewhat as they fall.

Through the evening hours, some additional showers and t-storms
are possible across northern and eastern parts of the area. The
best threat for any stronger storms with gust winds or hail will
likely be across northeastern areas and generally over the next
few hours. CAMs suggest the threat for any showers or storms
will diminish by 7 to 9 pm, as the loss of daytime heating and
disturbance moving away tends to end the threat.

After the warm day today, it will remain muggy and mild into the
overnight hours. Skies will become partly to mostly clear,
especially across southern areas. Some patchy fog may develop,
especially late tonight and for any locations that saw rainfall
during the day today. Overnight lows will mainly be in the low
to mid 60s (some upper 50s across the high terrain).
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&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
Behind the departing disturbance, upper level ridging will
briefly reestablish itself for Wednesday. With the ridging in
place, it looks like a fairly sunny day, with just some cu
developing over the high terrain by afternoon. 850 hpa temps are
expected to be around +15 C to +17 C. Highs should be in the
upper 80s to near 90 in valley areas, with upper 70s to mid 80s
in the high terrain, making this the warmest day of the year so
far. Even though it will be muggy, heat index values should stay
below advisory criteria, although caution is still urged for
anyone spending time outdoors, as this will be the first heat
event of the season.

Some high clouds may begin increase by late afternoon or early
evening as the next system begins approaching from the Great
Lakes. A surface pre-frontal trough will help initiate some
convection over western and central New York and this will
spread into the area for Wednesday evening into Wednesday night.
Although the best severe threat will likely be west of the area,
some gusty winds or hail can`t be ruled out for far western
areas as the storms enter the area on Wednesday evening. With
the loss of daytime heating, the threat for stronger storms will
diminish into Wednesday night, although some scattered showers
and t-storms are still possible. Otherwise, it looks partly
cloudy and muggy with lows in the 60s.

On Thursday, a surface cold front will be crossing the area from
west to east, mainly early in the day. Initially, there may only
be some isolated to scattered showers along the front as it
crosses western areas for early in the day. However, with
daytime heating in place, some additional showers and t-storms
may eventually develop along the front by afternoon, although it
will likely be passing through southeastern areas by the time
this occurs. Can`t rule out a locally strong storm for areas
south and east of Albany on Thursday afternoon, but most of the
area should be in the clear by that point. Temps will range from
the mid 70s in northwestern areas (where the front will pass
first) to the mid 80s in southern areas (where it won`t cross
until the afternoon hours).

Behind the front, some clearing should occur on Thursday night
with less humid air working its way into the area. Lows will be
more comfortable than recent nights, with temperatures down into
the 50s.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Although Friday looks rain-free and less humid than the past few
days, it doesn`t look as cool as what some models originally
suggested, as the upper level trough and associated cooler
temps/lower heights look to stay north of the area. Highs should
reach the lower to middle 80s in valley areas, although
dewpoints will only be in the 50s. With high pressure nearby,
skies should be fairly sunny through the day. It should stay
quiet into Friday night with partly to mostly clear skies and
temps in the 50s.

Over the holiday weekend, a series of upper level disturbances
should pass through the region. Although the exact timing and
track is still somewhat uncertain, it appears that the best
chance for precip will be on Saturday and again on Monday. Will
go with chance POPs for both Saturday and Monday, with slight
chance on Sunday. Best chance will be during the diurnally
favored afternoon and evening hours. Some rumbles of thunder
can`t be ruled out this activity as well. Daytime temps will
generally be in the 70s to low 80s, with 50s at night.

With the upper level trough building into the area, some
additional showers can`t be ruled out into Tuesday as well. Will
continue to keep chance POPs in place, with plenty of clouds and
temps still near seasonable levels, although the forecast is
more uncertain out this far.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
Through 00z Thursday...The threat for thunderstorms to impact
the terminals is now over, though some lingering showers persist
at KPSF this evening. Dry conditions will be resumed everywhere
upon the completion of this showers in the next hour with skies
becoming mostly clear overnight. KGFL was impacted by
thunderstorms the most this afternoon, getting a soaking rain
within and in the vicinity of its terminal. Therefore, it is
likely that, with skies remaining mostly clear there overnight,
that fog could develop. With lower confidence in the extent of
fog tonight, kept visibility within the MVFR to IFR thresholds
with room for amendments in future updates.

Fog will quickly burn off at KGFL upon daybreak tomorrow,
yielding VFR conditions everywhere once again. Throughout the
day tomorrow, some high-level cirrus clouds look to develop
ahead of an approaching upper-level disturbance and frontal
system, but conditions will remain VFR. It is possible that some
showers develop across the area before the end of the 00z cycle,
however, with low confidence in the spatial coverage of showers
due to their likely scattered nature and the likelihood of their
occurrence within the last hour or two of this period, kept
PROB30 groups out of the TAFs. Will provide updates as lead time
decreases.

Winds throughout the 00z period will be light and gradually
become southerly/southwesterly at speeds of 4-8 kt.

Outlook...

Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA.
Thursday: Moderate Operational Impact. Chance of SHRA...TSRA.
Thursday Night: Low Operational Impact. Slight Chance of SHRA.
Friday: No Operational Impact. NO SIG WX.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: Moderate Operational Impact. Chance of SHRA...TSRA.
Saturday Night: Moderate Operational Impact. Chance of SHRA...TSRA.
Sunday: Low Operational Impact. Slight Chance of SHRA.

&&

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

&&

$$

SYNOPSIS...Frugis
NEAR TERM...Frugis/Gant
SHORT TERM...Frugis
LONG TERM...Frugis
AVIATION...Gant