708
FXUS61 KALY 160456
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
1256 AM EDT Fri Aug 16 2024

.SYNOPSIS...
High pressure builds the region overnight through Friday,
giving us a warmer, mainly dry and more humid end to the work.
Conditions turn cloudy and remain muggy this weekend into early
next week as a slow moving disturbance approaches with chances
for rain increasing through the day Saturday before higher
chances for rain, potentially steady at times, arrive Sunday
through early next week.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
.UPDATE...Skies have become mainly clear, with satellite/obs
indicating patchy fog developing in typical sheltered areas. No
significant changes with this update.

.PREV DISCUSSION[1026]...A surface trough is moving across
northern and western New England, as the mid and upper level
trough is lifting north of Nova Scotia and New Brunswick. The
isolated showers/thunderstorms have diminished with the loss of
the diurnal heating.

A few thunderstorms became severe over Saratoga and Washington
Counties with 1-1.75" hail and some spotty wind damage. These
storms were loosely organized slow movers. The skies continue
clear prior to midnight with patchy fog developing already near
KGFL. The mainly clear skies (outside smoke and high clouds) and
light to calm winds will promote radiational cooling.

The mist/fog will be mainly below in the valleys, as high
pressure builds in. Lows will be mainly in the mid 50s to lower
60s.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
High pressure building southward from southern Canada becomes
established across the Northeast tomorrow as upper level
ridging from western NY builds eastward. This will support
mainly dry conditions with morning sun once again mixing with
some fair weather cumulus. CAMs continue to suggest a few
isolated showers/storms may develop along the spine of the
southern Greens so included slight chance POPs but subsidence in
the wake of the exiting low in the Canadian Maritimes should
squash most convection. Otherwise, upper level flow becoming
southwesterly will help usher in a warmer air mass with 850hPa
isotherms reaching +14C to +15C. Forecast soundings support deep
boundary layer mixing as drier air rotating around the mid-level
ridge advects into the region. This should support sfc temperatures
to become very warm reaching into the upper 80s in the valley
with low to mid 80s in the hill towns and upper 70s in the
higher terrain. Dew points rise into the low to mid-60s making
it feel quite muggy/uncomfortable.

Initially clear skies Friday evening will trend cloudier overnight
thanks to increased southwesterly flow contributing to moisture
advection ahead of the slow approaching mature/closed low from
the Great Lakes. Temperatures will be milder compared to
previous nights thanks to increased cloud coverage with
overnight lows in the low to mid 60s. It will continue to feel
muggy as dew points remain elevated.

The associated warm front/triple point from the approaching low
will be slow moving and with sfc high pressure shifting into
the Canadian Maritimes, southeasterly sfc flow will become
established. This will keep skies cloudy and conditions muggy
with the pressure gradient between the offshore high and
incoming low tightening. This should support somewhat breezy
southeasterly sfc winds with gusts up to 20kts at times. Cloudy
skies and onshore flow will keep temperatures cooler with highs
only topping out in the mid to upper 70s as remain ahead of the
warm front. The incoming low remains slightly positively tilted
and the stronger height falls will slowly spread from west to
east through the day, initially reaching the southern
Adirondacks and Mohawk Valley before spreading towards the
Hudson Valley during the afternoon. Thus, we continue to show
chance POPs for areas of showers Saturday morning rising to
likely for the western/southern Adirondacks and Mohawk Valley
with chance POPs spreading into the Hudson Valley by the
afternoon. Areas in western New England should remain dry most
of the day as they likely remain displaced far enough east.
Given the cloudy skies most of the day, overall instability will
be limited despite the muggy conditions. Therefore, we only
show chance and slight chance for thunderstorms mainly west of
the Hudson River where lapse rates will be a little steeper
closer to the low. Areas to the east will be under more of the
stable/marine influenced air mass.

Cloudy skies continue Saturday night keeping conditions mild
and muggy with overnight lows only in the mid to upper 60s.
Areas of showers remain possible, especially west of the Hudson
River, as the warm front and the associated low and mid level
convergence approaches.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Continued chances for rain and some thunderstorms capable of
heavy downpours continues Sunday into Monday as our slow moving
upper level low gradually opens up as it progresses from the
Great Lakes into the Northeast. Southerly flow ahead of the
trough axis will support moisture advection with PWATs nearing
or even slightly exceeding 1.50". Mostly cloudy skies will
likely limit overall instability but elevated dew points in the
60s will likely support at least some instability. We therefore
continue to message slight chance to chances for thunderstorms
but likely to even categorical POPS (60 - 90%) for rain Sunday
through Monday. There is potential for heavy downpours and repeated
areas of heavy rain as deep southerly flow is maintained
through the column within the moisture rich environment ahead
of the approaching trough Sunday with the sfc cold front and
trough axis tracking through on Monday. WPC considered
introducing a slight risk in its Excessive Rainfall Outlook for
Sunday - Monday but given uncertainty on the exact placement of
any heavy rain plus antecedent dry conditions, we collaborated
to just maintain a marginal risk at this time. Should confidence
increase that heavy rain may result in flash flooding, we can
revisit the need to upgrade to a slight risk in WPC`s ERO.

Guidance has trended to show drier conditions finally arriving
by Tuesday through Thursday as a large Canadian high pressure
from Canada builds southward, ushering in a drier and much
cooler air mass. Temperatures should actually run cooler than
normal for mid to late August standard with high temperatures
only rising into the 70s with overnight lows dropping into the
50s.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
Through 00Z Saturday...VFR conditions start the TAF cycle at
KALB/KGFL/KPSF/KPOU with some mid level and high clouds around,
as well as some high level smoke. Expecting the mid and upper
level trough to move away overnight near Nova Scotia with high
pressure building in at the surface.

The mostly clear skies and light to calm winds with recently wet
ground at KGFL will allow IFR/LIFR radiational mist/fog and low
stratus to form. We used a TEMPO group for IFR mist 04Z-07Z/FRI,
and then went IFR/LIFR to 12Z/FRI. KPSF also should see
radiational mist/fog form around 04Z-06Z and it continues to
about 12Z/FRI. KALB/KPOU we placed some MVFR patchy mist and
MIFG 09Z-12Z/FRI with less confidence with IFR conditions.

The mist/fog should dissipate around 12Z/FRI with VFR conditions
prevailing to the end of the TAF cycle at 00Z/SAT. Expect some
sct-bkn cirrus and a few cumulus 5-6 kft AGL.

The winds will become light to calm prior 04Z/FRI. The winds
will be light from the south to southeast less than 10 KT from
the late morning through the afternoon.

Outlook...

Friday Night: No Operational Impact. NO SIG WX.
Saturday: Moderate Operational Impact. Breezy. 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. Definite SHRA...TSRA.
Monday: High Operational Impact. Definite SHRA...TSRA.
Monday Night: High Operational Impact. Likely SHRA...TSRA.
Tuesday: Moderate Operational Impact. Chance of SHRA.

&&

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

&&

$$

SYNOPSIS...Speciale/Wasula
NEAR TERM...JPV/Speciale/Wasula
SHORT TERM...Speciale
LONG TERM...Speciale
AVIATION...Wasula