127
FXUS61 KALY 260606
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
206 AM EDT Wed Jun 26 2024

.SYNOPSIS...
After a few light early showers mainly north of Albany, clouds
give way to sunny, warm, and slightly breezy conditions today.
A period of moderate to heavy rain and embedded thunderstorms
overspread the region this evening along an incoming cold front.
Storms south of Interstate 90 will be capable of producing
gusty winds and heavy downpours that may result in localized
flooding. Cooler and even breezier conditions arrive for
Thursday as high pressure builds into the Northeast.

&&

.NEAR TERM /THROUGH TODAY/...

A mainly dry night is in store for eastern NY and western New
England with mid-level clouds keeping temperatures mild in the
70s. Regional radar shows a small area of rain and a few storms
tracking through Lake Ontario and high res guidance suggests
these showers weaken as they cross into NY but some showers look
to spill into the western Adirondacks by 09 - 12 UTC so
maintained chance POPs there with even slight chance POPs
extending into the Upper Hudson Valley to account for a few
light sprinkles early this morning before all showers end.

Then, early clouds give way to mainly sunny skies as zonal flow
strengthens aloft in response to an incoming potent shortwave
that will amplify as it swings into the Great Lakes. A pseudo
warm front/dew point boundary settles just south of I-90 this
afternoon with dew points north of this boundary across the
Greater Capital District, southern VT, Upper Hudson Valley, and
SW Adirondacks actually only rising into the upper 50s to low
60s as a pocket of dry air in the mid-levels tracks overhead and
supports deep boundary layer mixing. Not only will the deep
mixing result in temperatures warming into the mid to upper 80s
but westerly winds should also turn a bit breezy with gusts
reaching up to 20kts at times. South of this boundary
temperatures will be a bit warmer reaching into the low to mid
90s and higher dew points in the low to mid 60s will make it
feel even warmer. A few pockets of heat index values reaching 95
degrees likely in the mid-Hudson Valley but not enough coverage
to warrant a heat advisory.

Clouds increase late this afternoon from southwest to northeast
as sfc winds back to the south and warm air and moisture
advection increase ahead of an approaching cold front. Guidance
remains in good agreement that the majority of the incoming
rain and possible thunderstorms hold off until after 21 UTC but
given the strong dynamics, forcing for ascent, and moisture
fetch, rain may arrive a few hours earlier than high res
guidance suggests so we still introduce likely POPs for the mid-
Hudson Valley, the eastern Catskills, and Litchfield County by
21 - 00 UTC.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
The most active part of the period is expected to be Wed
evening into Wed night, as the aforementioned upper trough/cold
front track eastward across the region. A warm/moist air mass
will be in place just ahead of this system. Strong forcing and
sufficient moisture (PWAT anomalies of +1 to +2 STDEV) are
expected to lead to numerous showers and thunderstorms. With
evening into early overnight timing, the magnitude of
instability looks rather limited, with SBCAPE (< 500 J/KG)
across much of the area. The best overlap of just enough
instability and shear for severe storms looks to be across
southern portions of Ulster and Dutchess counties where there is
a small area of a Slight Risk (level 2 of 5) outlook. There
looks to be enough shear (0-6 km bulk shear of 40-50 kt) across
the entire area for storm organization, but really only enough
buoyancy to maintain sustained updrafts across these far
southern counties. The main threat looks to be damaging wind
gusts. The severe threat should be non-existent across the
northern 2/3 of the area. There is a Marginal Risk (level 1 of
5) from Albany and the Berkshires south, which has been trimmed
south compared to prior outlooks. Due to high PWATs, there will
be embedded downpours which could lead urban/poor drainage
flooding and isolated flash flooding where persistent or
repeated downpours occur. There is a Marginal Risk (level 1 of
4) of excessive rainfall across the entire area.

Showers and storms should start to taper off by ~1 to 3 AM from
west to east as the disturbance and front move east. Cold
advection begins late, which will result in low temperatures to
drop to the mid 50s in the higher terrain to lower 60s in the
Hudson Valley from around the Capital District south.

Cooler/drier conditions in store for Thu, as high pressure
builds eastward from the Great Lakes. There is just a low
probability for a few morning showers across far northern areas.
NW winds will gust to around 20-25 mph in favored areas,
ushering in less humid conditions(dewpoints dropping into the
50s). High temperatures should be near normal ranging from upper
60s in the W. Adirondacks to lower 80s in the mid Hudson
Valley. Thu night looks clear and cool with high pressure
directly over the area. Clear skies, a dry air mass (PWAT
anomalies of -1 to -2 STDEV) and light winds will lead to low
temperatures below normal with 40s in the mountains to lower/mid
50s in the valleys.

Dry/tranquil weather expected to persist Fri as high pressure
shifts eastward into New England during the day. Highs may be a
degree or two warmer than Thu, but overall temperatures will be
near normal with continued low humidity levels.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Active weather looks to return, as a warm front lifts northward
across the region Fri night into early Sat, followed by a cold
front passage Sat night into early Sun. Parameters lining up for
potential strong to severe storms and localized flash flooding
threat. GEFS already indicating anomalously strong SW winds and
significant deep layer moisture (850mb v-component wind and PWAT
anomalies of +2 to +3 STDEV) Sat to Sat night. Depending on
timing of forcing from any pre-frontal surface trough and the
cold front as well any significant disturbances aloft, will have
to monitor trends for possible severe and/or flash flood
hazards. Will continue mention of likely PoPs late Sat through
Sat night, with scattered to numerous thunderstorms expected.

The cold front should clear the area on Sun, with cooler/drier
air starting to gradually filter in during the afternoon as
winds become NW. With temperatures aloft still fairly warm,
highs could reach well into the 80s across lower elevations
although humidity levels should lower by later in the day. Will
linger mention of chance PoPs into the day due to account for
possible slower timing of the cold front passage and will refine
further once the weekend gets closer.

Good model consensus for a large area of high pressure building
in early next week, with dry conditions, near normal
temperatures and comfortable humidity levels.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
Through 06Z/Thu...VFR conditions are expected through daybreak,
despite a few showers tracking southeast and affecting KGFL/KALB
between 09Z-13Z/Wed as a warm front approaches.

There could be borderline MVFR Cigs for a brief time between 13Z-
16Z/Wed at KALB and KPSF, otherwise mainly VFR conditions through at
least mid afternoon. Later this afternoon, scattered
showers/thunderstorms may develop at KPOU, with more widespread
showers and thunderstorms expected after 00Z/Thu at KALB, KPOU and
KPSF as a wave of low pressure tracks just south of the region.
Occasional MVFR/IFR Vsbys/Cigs will be possible within any heavier
showers/thunderstorms this evening. The best chance of thunderstorms
will be at KPOU and KPSF, although some chance that thunderstorms
reach as far north as KALB.

South to southwest winds 5-10 KT with a few gusts of 15-20 KT
through daybreak will then shift into the west by late morning at
similar speeds/gusts. West to northwest winds will decrease to less
than 5 KT toward and after sunset, although may become southeast at
KPOU around 5 KT.

Winds will be stronger, and variable in direction near and within
any thunderstorms.

Outlook...

Wednesday Night: High Operational Impact. Definite SHRA...TSRA.
Thursday: Low Operational Impact. Breezy. 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: Moderate Operational Impact. Breezy. Likely SHRA...TSRA.
Saturday Night: High Operational Impact. Likely SHRA...TSRA.
Sunday: Moderate Operational Impact. Chance of SHRA...TSRA.

&&

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

&&

$$

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