-- Discussion containing changed information from previous version are highlighted. --
755
FXUS61 KALY 260230
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
1030 PM EDT Tue Jun 25 2024

.SYNOPSIS...
A warm front will move across the area tonight, bringing widely
scattered showers and perhaps a few thunderstorms. Warm and more
humid conditions are expected on Wednesday, then a cold front
will bring more widespread showers and thunderstorms late
Wednesday afternoon into Wednesday night. Cooler and drier
weather will be ushered in for Thursday into Friday as high
pressure builds in.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --
.UPDATE...As of 1030 PM EDT, a warm front will continue to
cross the region tonight. An initial band of light rain showers
has pushed across the Adirondacks, Mohawk Valley and Hudson
Valley from Albany and points north advancing eastward into
southern Vermont and northern Berkshire County. Additional
showers are moving back into the Adirondacks. These showers are
producing light QPF amounts. Still expecting isolated to
scattered rain showers through the overnight mainly from
Interstate 90 and points north.

Previous Discussion:
High level clouds continue to increase/thicken ahead of an
upper level short wave and associated surface warm front
approaching from the lower Great Lakes. Moisture will start to
return as the warm front pushes through tonight, but since the
air mass will be starting out dry, coverage of showers should
only be isolated to widely scattered with the highest chances
north/west of Albany. HREF indicating some limited elevated
instability (MUCAPE < 250 J/Kg), so a few rumbles of thunder may
occur in the W. Adirondacks. With the increasing clouds and a
southerly breeze developing, lows will be mild ranging from the
60s to around 70.

The warm front lifts north of our area on Wed, with a W-SW flow
ushering in a somewhat more humid air mass. Dewpoints are
expected to rise into the lower/mid 60s in most valley locations
during the afternoon. 850 mb temperatures anomalies from the
GEFS look to be +1 to +2 STDEV, so it will be warm with highs in
the mid 80s to near 90 in lower elevations. A potent and
progressive upper level trough and associated surface cold front
will start to approach from the west late in the day. Based on
the latest timing from the CAMs and global guidance, it appears
that any shower and thunderstorm development will likely hold
off until very late afternoon or early evening, so will only
maintain 20-40% PoPs for areas well south/west of Albany through
6 PM.
-- End Changed Discussion --

&&

.SHORT TERM /WEDNESDAY NIGHT 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 /03Z WEDNESDAY THROUGH SUNDAY/...
Through 00z/Thu...VFR conditions will start the TAF period at
all sites as mid-level clouds increase this evening, lowering to
around or slightly below 5000 feet toward daybreak Wednesday.
Rain showers associated with a passing warm front will move
across KALB/KGFL tonight so will maintain VCSH at these sites as
both cigs/vsbys may remain VFR. While a shower may be near
KPSF, most of the activity looks to stay to the north. No rain
is expected at KPOU tonight. Cigs may briefly lower to the MVFR
range at KALB/KGFL/KPSF around 12z/Wed before quickly lifting
back to VFR by 14-15z/Wed. VFR conditions are then expected
through Wednesday afternoon as the next round of precipitation
looks to hold off until after 00z/Thu.

Wind will be south to southwesterly tonight at 10 kt or less,
then become west to southwesterly at 10-15 kt on Wednesday with
a few gusts 20 to 25 kt. Periods of LLWS may occur at KPOU
between 4-10z/Wed as winds at 2000 feet increase to 35 to 40 kt
with surface winds remaining around 5 kt. Surface wind may pick
up soon enough at KPSF to prevent LLWS concerns there but will
monitor trends tonight.

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