258
FXUS61 KALY 161055
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
655 AM EDT Tue Jul 16 2024

.SYNOPSIS...
Hot and humid conditions continue today with scattered strong
to severe thunderstorms developing this afternoon and evening. A
cold front will bring additional scattered thunderstorms
Wednesday along with continued warm and humid conditions. Cooler
and much less humid conditions along with fair weather will
follow in the wake of the front for Thursday into Friday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
**Heat Advisory remains in effect for the Hudson Valley
 including the Capital Region, the Mohawk Valley, Lake George
 Saratoga Region, northwest Connecticut and now eastern Windham
 County until 8 PM Tuesday.**

** Scattered severe thunderstorms possible this afternoon and
 evening across eastern NY and adjacent western New England **

.UPDATE...As of 630 AM EDT, still quite a bit of lower clouds
for areas north of I-90, especially higher elevations. Some
patches of drizzle/sprinkles across the southern Adirondacks and
upslope areas of southern VT are diminishing.

Expect clouds across northern areas to gradually erode from
south to north by mid morning, with mostly sunny skies elsewhere
through this morning.

MCV across southern Michigan will continue tracking
east/northeast today, with convection developing ahead of it
across western/central NYS later this morning and then spreading
into eastern NY from west to east between roughly 3 PM and 8 PM.
Damaging winds will be the main threat from these storms, though
isolated instances of large hail may also occur, and a low
probability (~2% per SPC) of tornadoes also exists for the
Mohawk Valley, southern Adirondacks and Lake George/Saratoga
region.

[PREVIOUS 357 AM EDT]...As of 350 AM EDT, spotty light
showers/patchy drizzle continues for areas mainly north of I-90,
as remnant low level circulation from previous MCV tracks east
across the southern Adirondacks. We expect these showers/drizzle
to expand into southern VT over the next hour, with occasional
light showers/drizzle gradually tapering off from west to east
toward or after 6 AM.

Weak shortwave ridging should allow for a period of sunshine for
most areas after any early morning low clouds lift. Temperatures
should rise rapidly through this morning and early afternoon in
response to mostly sunny skies and warm temperatures aloft.

Meanwhile, next MCS currently across the southern Great Lakes
will continue tracking east. Although main convection may weaken
this morning, lingering outflow on its leading edge will likely
serve as a focus for additional convective initiation across
western/central NYS later this morning, which should then track
east later this afternoon. By late afternoon, instability builds
with HREF Mean MUCAPES reaching at least 1000-1500 J/kg for most
areas, greatest near and south of I-90. 0-6 km shear will
strengthen to around 30-35 KT, allowing for some potential storm
organization.

Latest CAMs suggest another potential QLCS with bowing segments
moves west to east across the region between roughly 3 and 8
PM. Scattered damaging wind gusts appear to be the greatest
threat, however should any discrete cells occur, isolated large
hail can not be ruled out. In addition, there is a low
probability (~2%) for a tornado for areas along and north of
I-90, where low level shear will be greatest (0-1 km SRH
~100-150 m2/s2 per HREF mean).

Max temps should reach the lower/mid 90s within many valley
areas once again, with dewpoints generally between 65-70. This
should allow maximum heat indices to reach 95-100 in most valley
areas, where a heat advisory remains in effect until 8 PM this
evening.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
Ongoing showers/thunderstorms should shift east of the region by
10 PM. In their wake, expect partly cloudy skies with patchy fog
forming. Lows mainly 65-70.

Another active day possible Wednesday, with greatest chances for
scattered severe thunderstorms generally from the Capital Region
and points south and east, where greatest instability (HREF mean
MUCAPES 1000-1500+ J/kg) overlaps modest deep layer shear (0-6
km shear ~30-35 KT). Deep layer shear will be stronger farther
north, however instability will be more questionable for these
areas as a pre-frontal trough may scour out higher dewpoints and
better instability prior to peak heating and approaching cold
front. SPC has placed areas from the Capital Region south and
east, including southern VT, within a Slight Risk for severe
thunderstorms, with a Marginal Risk for the remainder of the
region. Isolated to scattered damaging wind gusts appear to be
the greatest severe thunderstorm threat.

Lingering showers/thunderstorms Wednesday night, which could
even linger into Thursday morning across the mid Hudson
Valley/NW CT region as a wave developing along the front and
sharpening upper level trough approaches from the west. By
Thursday afternoon, cooler and much less humid conditions
overspread the region, with a mix of sun and clouds and somewhat
breezy conditions developing (west/northwest winds possibly
gusting up to 25 mph). Max temps should reach the lower/mid 80s
in valleys, with mainly 70s for higher terrain areas. Dewpoints
should fall into the mid 50s to around 60 in the afternoon.

Mainly clear and cooler for Thursday night, with lows in the mid 50s
to lower 60s for many areas, with some 40s possible across
portions of the southern Adirondacks.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Much of the long term period will be dry with seasonable
temperatures. High pressure will remain anchored across the
region Friday into Saturday with dry weather and comfortable
humidity levels. A weak cold front will slowly push southward
later Saturday through Sunday, but may have little to no
moisture to work with. In addition, we may be under the
influence of mid-level confluent flow. As a result, most areas
could remain dry, but an isolated shower cannot be ruled out.
High pressure then reestablishes itself on Monday with continued
dry and comfortable weather. Highs each day will be in the 70s
and 80s with lows in the 50s and 60s.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
Through 12z/Wed...Cigs have lifted back to VFR and should remain
VFR into the early afternoon hours. A broken to solid line of
showers and thunderstorms is expected to cross the TAF sites
later this afternoon and evening, especially between 21z/Tue and
00z/Wed. Have reduced the PROB30 groups to 2 hours for the most
likely timing of the storms. Gusty winds can occur with these
storms along with reductions to IFR/MVFR.

Cigs/vsbys should lift back to VFR in the wake of these storms
with precipitation chances ending. There is some uncertainty on
whether or not any patchy low level stratus and/or fog develops
overnight. Will refer to later outlooks to address this
potential.

Wind will become south to southwesterly at 7 to 15 kt today with
a few gusts to around 20 kt, then decrease to less than 10 kt
tonight.

Outlook...

Wednesday Night: Moderate Operational Impact. Scattered SHRA...TSRA.
Thursday: No Operational Impact. NO SIG WX.
Thursday Night: No Operational Impact. NO SIG WX.
Friday: No Operational Impact. NO SIG WX.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: No Operational Impact. NO SIG WX.

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory until 8 PM EDT this evening for CTZ001-013.
NY...Heat Advisory until 8 PM EDT this evening for NYZ038>041-043-
     049-050-052-053-059-060-064>066-083-084.
MA...None.
VT...Heat Advisory from noon today to 8 PM EDT this evening for
     VTZ015.

&&

$$

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