961
FXUS61 KALY 292359
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
759 PM EDT Mon Apr 29 2024

.SYNOPSIS...
A frontal boundary will be lifting back northward
tonight, allowing for some spotty showers overnight.  A stronger
disturbance will allow for some additional showers and scattered
thunderstorms for later Tuesday into Tuesday evening. Drier weather
will return for Wednesday with seasonable temperatures.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
.UPDATE as of 713 pm EDT...Initial isolated showers and
convection developed south of the forecast area over the lower
Hudson River Valley north of the stalled front. A little lull is
expected over the next few and we reduced the PoPs. We started
the slight and low chance PoPs for showers and isolated
thunderstorms south and west of the Capital Region until 8-10 pm
and 10 pm to midnight closer the Capital District based on the
CAMS and radar trends. Some adjustments to cloud cover with the
sfc high building in from the north and the mid level ridge axis
aloft and the hourly T/TD/RH trends.

.PREV DISCUSSION [346 PM EDT]...Stalled frontal boundary
continues to be located across the Catskills, mid Hudson Valley
and across western New England. To the south of the boundary,
skies are still partly to mostly sunny, with temps well into the
70s and low 80s and dewpoints in the 60s. Meanwhile, areas to
the north, including the Capital Region, are still mainly in the
50s, with widespread low clouds and northerly winds. This front
will remain fairly stationary, perhaps settling southward this
evening towards the lower Hudson Valley.

Visible satellite imagery continues to show a band of lower
clouds over northern areas, although these have started to break
up compared to earlier in the day. Southern areas are seeing
some diurnal cumulus. Although the diurnal cumulus will start to
dissipate around sunset, the persistent southerly flow to the
south of the front will allow for some low stratus to form for
tonight. These low stratus clouds overspread the entire area for
tonight, as the onshore flow and nocturnal cooling allow for
plenty of clouds.

CAMs suggest some scattered showers will be developing south and
west of the region for this evening within the area of better
moisture and instability. Through the overnight, some of this
activity may start to spread into our area. Instability will be
limited across our area due to the stable low-levels, but an
elevated rumble of thunder can`t be ruled out. Any shower
activity looks fairly brief and mainly spotty, with the best
chances across western and southern areas.

Lows overnight will range from the mid 40s in northern areas to
the mid 50s in southern areas.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
The upper level ridge that is in place over the eastern CONUS
will be shifting eastward and weakening for Tuesday as it heads
offshore. Meanwhile, upper level dynamics will be weak, as a
disturbance running into the departing ridge heads to the
northeast and starts to fall apart. There still will be the
surface boundary draped across the region and a weak area of low
pressure will be sliding along this front.

While Tuesday will start off fairly quiet with just a partly to
mostly cloudy sky, the chance for precip will be increasing
through the day. CAMs suggest a cluster of showers and t-storms
will be accompanying the low pressure area as it slides
eastward along the front. The best timing for this for our area
looks to be the afternoon and evening hours.

There should be enough sun across the entire area for temps in
the upper 50s to low 60s, but dewpoints remain fairly low in the
50s and the low- levels should be fairly stable. The better
warmth and moisture will remain south and west of the region
through the day. At this point, it looks like instability will
remain fairly limited, so any thunder looks fairly isolated.
There could be some lingering elevated thunder that occurs due
to surface-based storms to the west running into our area.
Decent lapse rates are in the place aloft, so small hail can`t
be totally ruled out, but the stable low levels should help
prevent any strong winds from occurring with any storms. PWATs
and dewpoints don`t look too high for this time of year, so
while some ponding can`t be ruled out, downpours don`t look
long/hard enough for bigger flooding issues. This activity could
linger into the first part of Tuesday night, but it should be
clearing out by the late night hours, with temps in the 40s to
low 50s.

On Wednesday, mainly drier weather is expected across most of
the area. There still could be a few spotty light rain showers
(especially northern areas) as an upper level disturbance passes
by to the north, but overall it looks drier and more seasonable
for the entire area, with highs in the 60s and a partly to
mostly cloudy sky. Better clearing is expected for Wed night
with lows in the 40s to low 50s.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Upper level ridging looks to set up across the area for Thursday
into Friday. This should allow for mainly dry conditions, with
more sun that recent days and mild temps. Have gone with highs
in the 60s to low 70s for both days with upper 40s to low 50s at
night. Will keep a slight chance in for POPs in case something
sneaks around the ridge from the north, but most places should
wind up staying dry.

Over the weekend, there could be a threat for some showers once
again as a frontal boundary approaches from the west. The timing
is still somewhat uncertain, but will tend to favor the
diurnally favored time periods for any showers. Temps still look
fairly mild, with most areas well into the 60s for highs along
with a partly cloudy sky.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
A frontal boundary will lift northward as a warm front tonight
with scattered showers and isolated/scattered thunderstorms. The
conditions will start out as VFR at KALB/KPOU/KPSF/KGFL with mid
and high clouds increasing. Some scattered showers may develop
south of KALB 02Z-04Z/TUE and then expand north to
KALB/KPSF/KGFL between 03Z-06Z/TUE with MVFR cigs/vsbys. Some
thunderstorms are possible, but we kept them out of the TAFs
with lower probs at this time. After 06Z/TUE scattered showers
and isolated thunderstorms will continue, as the boundary moves
north. The TAF sites will get into the deeper low-level moisture
and expect widespread IFR/MVFR cigs and MVFR vsbys to develop
prior to 12Z/TUE. Some drizzle may also linger in spots.

The cigs should increase to widespread MVFR levels at 1-3 kft
AGL between 14Z-18Z/TUE as they get into a warm sector. A low
pressure system and an upper level disturbance will approach in
the afternoon with showers and thunderstorms with MVFR and
localized IFR conditions. We used PROB30 groups for the chance
of thunderstorms at KALB/KGFL and showers for KPSF/KPOU
generally between 20Z/TUE and 00Z/WED.

The winds will vary in direction from north to west at 7 KT or
less early tonight and then will be variable in direction at 5
KT or less overnight. The winds will increase from the east to
southeast at 8-12 KT in the late morning through the afternoon
with gusts to 20 KT at KALB.

Outlook...

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

&&

.HYDROLOGY...
Mainly dry weather will continue through the evening hours.
Overnight, some spotty showers are possible along a stalled
boundary across southern areas and this front will be slowly
heading back northward as a warm front. A stray thunderstorm
can`t be ruled out overnight along this front, but it should be
fairly isolated.

After a dry start to Tuesday, more showers and thunderstorms are
expected by later in the day as a frontal boundary approaches
from the west. The low level flow out of the south will bring
in plenty of moisture into the region ahead of the boundary,
although dewpoints and PWATs won`t be overly excessive for this
time of year. Still, the strong forcing should allow for a
fairly widespread areas of showers and thunderstorms.  Some of
these showers and thunderstorms may contain heavy downpours,
which could lead to ponding of water in urban or low lying
areas. WPC has placed much of the region within a Marginal Risk
for Excessive Rainfall during this period. Overall, rainfall
amounts will generally be under an inch and no flooding of
main stem rivers is expected.

&&

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

&&

$$

SYNOPSIS...Frugis/Wasula
NEAR TERM...Frugis/Wasula
SHORT TERM...Frugis
LONG TERM...Frugis
AVIATION...Wasula
HYDROLOGY...Frugis