296
FXUS61 KALY 261751
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
151 PM EDT Sun May 26 2024

.SYNOPSIS...
Today will start out dry, with widely scattered showers and
thunderstorms developing during the afternoon mainly south of
Albany. A stronger low pressure system is expected to bring a
widespread rainfall with localized downpours and breezy
conditions Monday into Monday night. Chances for showers will
linger through much of the week with an upper level trough
remaining in place.

&&

.NEAR TERM /THROUGH TONIGHT/...
.UPDATE...Fair weather cumulus have developed over much of the
area with high pressure dominant. A weak surface boundary sits
south of the region with a few pin-head showers developing just
south of our CWA border. Temperatures have risen into the upper
70s to low 80s across valley areas with some mid/low 70s at
higher terrain. Some scattered showers and thunderstorms are
still expected this afternoon into this evening with the
boundary remaining present south of Albany. However, most areas
will remain dry.

Few changes were necessary with this update outside of
adjustments to reflect latest obs and trends. See previous
discussion below for additional details.

.PREV DISCUSSION[0345]...A disturbance will move east of the
area by early this morning, with weak high pressure building in.
Through much of today, upper level heights will be rising with
short wave ridging developing. At the surface, a diffuse front
will be in place across the southern part of the area. This
boundary will be the focus for widely scattered showers and
thunderstorms to develop during the afternoon given sufficient
instability around 500-1500 J/Kg. This activity should be
limited to areas in proximity to the front, which is from around
Albany southward. While there may be a few stronger storms, the
threat of severe storms still looks to be low, as forcing is
weak and 0-6 km shear will be ~20-25 kt. Temperatures will be
above normal, with highs mid/upper 70s in the mountains and
lower/mid 80s in the valleys. It will feel more humid compared
to the past few days for areas south of Albany, as dewpoints are
expected to reach the lower 60s.

Any showers/storms are expected to dissipate during the evening
due to diurnal effects and limited forcing. Upper level ridge
axis will progress eastward across the area through the night,
which should keep conditions mostly dry. A large upper level
trough and associated surface cyclone will start to approach
from the Great Lakes late tonight, but forcing from a lead short
wave should generally remain just to our west through daybreak.
Just a few showers will be possible with thickening clouds.
Lows will be mild with mainly upper 50s to lower 60s.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Monday looks to be a somewhat active day with potential for
downpours and breezy/gusty winds. The culprit is a deepening
cyclone with MSLP anomalies increasing to -2 to -4 STDEV as it
tracks from near the upper Great Lakes Mon morning to SE Ontario
by Mon evening. Southerly winds will strengthen ahead of the
cyclone, with 850 mb v- component(southerly) wind anomalies
increasing to +2 to +4 STDEV. Gusts to around 30 mph are
expected to develop. A few rounds of showers are possible during
the morning, with better forcing arriving during the afternoon
to evening associated with a disturbance aloft and an eastward
advancing surface front. Will continue to mention
likely/categorical PoPs during this time. While it will be
moist/humid, we will likely not get into a true warm sector in
eastern NY/western New England, so surface-based instability
looks weak with only a few hundred J/Kg of CAPE. However, given
strong wind field and deep layer shear, isolated strong winds
gusts cannot be ruled out. This system is now within the hi-res
model time window, with some indicating a narrow cold- frontal
rain band(NCFRB) tracking eastward across our area. So there is
the threat for localized downpours/heavy rainfall within
convective lines as PWAT anomalies climb to +1 to +3 STDEV. This
could lead to some urban/poor drainage flooding and isolated
flash flooding. Generally 1.00-1.50" QPF is forecast with 2" in
the S. Adirondacks and SE Catskills. However, locally higher
amounts are possible within persistent downpours. There
continues to be a Marginal Risk (level 1 of 4) of Excessive
Rainfall from WPC for most of the area, with a small area of
Slight Risk (level 2 of 4) in the SE Catskills.

As the cyclone tracks into western Quebec Mon night, the
occluded front will push eastward across our region through
early Tue morning. Will mention the highest PoPs through around
midnight, when tapering off from west to east overnight. Lows
will be mild again ranging from mid 50s in the Adirondacks to
lower/mid 60s in the Hudson Valley.

With the surface front east of our area, it should be mainly
dry on Tue. However, with upper level troughing and an
additional weak disturbance moving through will mention isolated
to scattered showers with a few T-storms possible. With no
discernible change in air mass and more sunshine, highs will be
quite warm ranging from upper 60s in the Adirondacks to lower
80s in the Hudson Valley.

Another short wave will start to approach late Tue night, but
doesn`t really get here until Wed, so will just mention
slight/low chance PoPs for areas north/west of Albany. Lows will
be cooler with mainly 50s expected.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Upper level trough will be moving across the region on
Wednesday. There are some differences in the models, as some
guidance suggests the best upper level forcing will be passing
by to the south of the region. Even so, there should be a good
chance for showers over much of the area, especially during the
afternoon and evening hours. Will have high chance to likely
POPs over much of the region. With some minor amounts of
instability present, will also mention the potential for some
rumbles of thunder, especially southern areas, although there
probably won`t be enough instability for any strong storms. With
the clouds and precip, temps will generally be held down into
the 60s to mid 70s.

The upper level trough will remain over the region and may even
become cutoff for Thursday into Friday. With some drier air
moving in from the west, the chance for showers should decrease,
but will still mention a slight chance for Thursday into
Friday, mainly for eastern areas. Sky cover will gradually
improve as well, with a partly sunny sky for Thursday and
eventually a partly to mostly sunny sky by Friday. With the
lower heights and cool temps aloft in place, highs will be below
normal with 60s to low 70s for Thursday into Friday. Overnight
lows will be cool in the 40s, but still not cold enough for any
frost or freeze conditions.

As an upper level ridge and warming temps aloft returns for the
weekend, temps will return back to seasonable levels for
Saturday, along with dry conditions and plenty of sunshine.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
VFR conditions with just a few clouds well above 3000 feet through
this evening. There could be an isolated shower or thunderstorm
between 20Z and 03Z but too isolated to put into the forecast. If a
shower or thunderstorm does develop, then it can be tracked and if
one is headed for a TAf site, the TAF will be amended.

VFR continues through much of the night, as high clouds spread
across the region ahead of an approaching upper disturbance and warm
front. By around 07Z to 12Z, lower clouds will develop and spread
into the region, at around 3000 feet, bringing MVFR ceilings to the
region. Between 12Z and 18Z Monday, intervals of showers will
develop with visibilities bordering on MVFR due to the light rain,
but ceilings will drop to the lower ranges of MVFR, trending toward
IFR.

Winds will be light and variable this afternoon and night.  Then,
winds become southeast Monday morning at just under 10 Kt, with a few
gusts to 15 Kt at KALB and KGFL.

Outlook...

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

&&

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

&&

$$

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