737
FXUS61 KALY 051730
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
130 PM EDT Fri Jul 5 2024

.SYNOPSIS...
With a warm and humid air mass in place and a nearby
frontal boundary around, some showers and thunderstorms are possible
for this afternoon. There will be a continued threat for
showers and thunderstorms tonight into Saturday as a cold front
moves across the region, with hot and muggy conditions remaining
in place. Rain-free weather will return for Sunday into Monday,
although temperatures will continue to be above normal.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
.UPDATE...As of 110 PM EDT, diffuse frontal boundary remains
just north of the Mohawk Valley/I-90 corridor, with dewpoints in
the lower/mid 70s to the south, and 60s to the north, with even
some lower 60s across far northern Herkimer/Hamilton Cos.

Showers with locally heavy downpours have been occurring across
portions of southern VT, particularly across higher terrain
areas, with additional showers entering the eastern Catskills.

Latest SPC Mesoanalysis indicates 100mb ML CAPES of 1000-1500
J/kg for areas southeast of the Capital Region extending into
the mid Hudson Valley, Berkshires and NW CT. As the showers from
the west continue tracking east, some convective initiation may
occur on the eastern edge. Main threat for any
showers/thunderstorms will be locally heavy rainfall, however
can not rule out an isolated stronger wind gust due to
precipitation loading. Best chance for thunderstorms should
remain generally south of I-90 through this afternoon.

Farther north, although isolated showers are expected, slightly
less instability should limit thunder potential outside southern
VT.

Across the SW Adirondacks, generally mostly sunny skies are
expected through early/mid afternoon, before some clouds build
up and a couple of showers possibly develop later this
afternoon.

Late afternoon high temps generally 85-90 for most valley areas,
and mid 70s to lower 80s across higher terrain areas. Heat
indices may briefly reach the mid 90s across portions of the mid
Hudson Valley, southern Litchfield County, and possibly the
Capital Region this afternoon.

PREVIOUS DISCUSSION [0629 AM EDT]...As of 629 AM EDT...Surface
boundary remains stalled over the region this morning. Areas
south of the front are seeing a light southerly flow, while
northern areas are fairly calm. All areas are fairly warm and
muggy to start the day, with dewpoints around 70 F. Aloft, the
flow is out of the west- southwest, with an upper level
disturbance well upstream of the area over the Midwest. The weak
surface front will remain stalled over the area through much of
the day today, but may start to slowly lift northward as a warm
front towards the early evening hours.

IR satellite imagery shows fairly widespread clouds in place,
mostly mid level clouds. MRMS shows some spotty showers are
ongoing, especially for the Adirondacks and western New
England. They showers should be pushing off to the east, so most
areas will be starting the day rain-free, although it will be
muggy with some patchy fog and a partly to mostly cloudy sky.

While the morning will start off fairly dry, there will be a
threat for some showers and thunderstorms by afternoon,
especially for southern areas. CAMs suggest that a cluster of
showers and thunderstorms (currently over the Upper Ohio Valley)
may spread towards southern areas by afternoon, although models
differ on the exact placement and strength of this activity. If
enough breaks of sun occur, there could be enough instability
around (about 1000 J/kg) to allow for a locally strong storm,
although storms will be fairly brief due to poor lapse rates
aloft. There will be some shear aloft as well, although it`s
fairly top-heavy and will depend on if a storm can get tall
enough. Can`t totally rule out a rogue strong wind gust today
with a wet microburst when a storm collapses, but main threat
may wind up being heavy downpours, as high PWATs/dewpoints could
lead to high rainfall rates and some localized flooding of
urban or poor drainage. This will be especially true if any
location sees more than one shower or storm.

While there will be a lot of clouds to start the day, there
should be enough breaks to allow for partly sunny skies by the
mid to late morning and into the afternoon hours. This will
allow for temps to reach well into the 80s for most valley
areas. Along with dewpoints in the 70s, this will make for heat
index values into the low 90s. Values should be just shy of
advisory criteria, but it will be close and anyone spending time
outdoors should use caution to avoid heat related illnesses.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
As the stalled frontal boundary lifts northward for tonight,
some additional showers and storms will be possible. CAMs show a
variety of different solutions for tonight as well, although
western and southern areas may have the highest coverage. With
the nocturnal timing, surface inversion should help prevent the
threat for any strong winds, but heavy downpours will continue
to be a threat. Lows will remain mild and muggy near 70 with
plenty of clouds around.

On Saturday, there may be some morning convection that is
moving west to east to start the day after daybreak, but skies
should clear out enough for a partly sunny sky by the mid to
late morning hours. With another warm and very humid day
(dewpoints into the mid 70s), it will be yet another day where
heat index values may be close to advisory criteria in valley
areas. It will probably be just short, but definitely high
enough where caution should be encouraged to all spending a lot
of time outdoors.

In addition, there will be a threat for some additional shower
and t-storms in the afternoon or evening ahead of the advancing
weak surface cold front, although coverage looks fairly low,
and the highest threat may be for eastern areas (Taconics into
western New England). As with Friday, the main threat looks to
be heavy downpours, although a rogue severe storm can`t be
totally ruled out, as the upper level shortwave lifts from the
upper Great Lakes and into southern Canada, so there may be some
decent dynamics not too far from the area. The threat for
precip will be winding down on Sat night as the surface cold
front pushes eastward. Lows will fall into the 60s, although it
will still be fairly humid with a partly cloudy sky.

On Sunday, it still looks fairly warm, despite being behind the
front. Dewpoints look a tad lower than Saturday, but still
pretty sticky with values well into the 60s to near near 70. The
main difference compared to Saturday will be that no precip is
expected and skies will feature more sun, with a mostly sunny
sky. Highs should reach well into the 80s once again, with a few
spots topping out around 90. Heat index values may reach into
lower 90s again for some areas. It will be dry on Sunday night
with a mostly clear sky. This may allow for lows to fall a
little more than the last few nights (especially in the
Adirondacks), with lows ranging from the upper 50s in northern
areas to the upper 60s in the Capital Region.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
The extended forecast period begins Monday with dry conditions
anticipated across eastern New York and western New England courtesy
of upper-level ridging aloft accompanying high pressure at the
surface. It will, however, be another hot day with highs looking to
reach the upper 70s/mid 80s at higher elevations and upper 80s to
low 90s in large valley areas. Dewpoints will be slightly elevated,
especially in the Hudson Valley where mid to upper 60s appear
likely, which could make conditions fair on the uncomfortable side.
However, at this time, heat indices look to remain below advisory
criteria in the low 90s.

Monday night into Tuesday, the upper ridging begins to weaken as an
upper-level disturbance and associated frontal system strengthens
upstream and slides eastward. Simultaneously, the surface
anticyclone shifts south and east away from the region to allow a
surface trough to build in in its wake. Some light, scattered
showers are possible with this initial disturbance mainly for
upslope areas (Eastern Catskills and Western Adirondacks) west of
the Hudson on Tuesday morning. However, as the axis of the upper
trough digs further into the Ohio Valley and Great Lakes regions
throughout the day and the surface trough strengthens ahead of the
primary low and attendant cold front, showers and embedded rumbles
of thunder will become more widespread. There still remains some
uncertainty regarding timing, but general consensus indicates a
greater spatial coverage by Tuesday afternoon/evening.

Showers look to continue Tuesday night into Wednesday morning,
gradually becoming less widespread as the upper trough weakens and
the cold front tracks through by Wednesday afternoon. Some embedded
rumbles of thunder will remain possible Tuesday night, but with the
loss of daytime heating and models indicating limited instability,
they may be few and far between. Some additional showers and rumbles
of thunder will be possible Wednesday night into Thursday morning as
we remain under cyclonic flow. However, tranquil weather will return
for most Thursday afternoon into Thursday night as dry air is
ushered in behind the departing system.

High temperatures Tuesday will be similar to Monday with upper 70s
to mid 80s at higher elevations and upper 80s with pockets of near
90 elsewhere. Wednesday and Thursday will then be cooler with
mid/upper 70s to low 80s above 1000 ft and mid and pockets of upper
80s in the valleys. Low temperatures Monday night and Tuesday night
will range primarily in the 60s with pockets of near 70 in the
Hudson Valley. Wednesday night and Thursday night will see
temperatures fall to the upper 50s to mid/upper 60s.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
Weak cold front supporting some scattered showers later this
afternoon, mainly at KALB, where TEMPO included for MVFR
visibilities through about 21Z. Just VCSH at KGFL, KPSF and
KPOU.

There should be a break in the rain this evening but more showers
and thunderstorms develop and increase in coverage between about
midnight and 10Z Saturday at all TAF sites. The best chances for
showers and thunderstorms is between about 09Z-15Z Saturday, where
MVFR visibilities and MVFR ceilings are indicated. Some IFR ceilings
and visibilities possible at KPSF. After about 13Z-15Z Saturday,
most of the showers will exit but there could still a few scattered
showers around, so including VCSH through 18Z Saturday.

Winds will be variable e but mainly south to southwest at less than
10 Kt this afternoon, diminishing to less than 6 Kt tonight and
continuing at less than 6 Kt Saturday.

Outlook...

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

&&

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

&&

$$

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