752
FXUS61 KALY 302359
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
759 PM EDT Tue Apr 30 2024

.SYNOPSIS...
Showers and isolated thunderstorms will diminish tonight
as a low pressure system and frontal boundary moving across the
region.  Behind this system, mainly dry and seasonable weather is
expected for Wednesday and Thursday.  Continued comfortable
conditions are expected for Friday into the weekend, although there
will be a chance for some showers over the weekend.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
.UPDATE as of 716 pm EDT...The thunderstorms have pretty much
diminished across the forecast area. A stratiform rain shield
has evolved ahead the wave moving along the boundary. We did
keep a slight chance of thunderstorms for a few more hours for a
rogue rumble or two with the best chance across the southeast
Catskills, mid Hudson Valley, Berkshires and NW CT. We also
removed all the small hail and gusty wind wording. Temps are
cooling in the 50s and lower 60s with the wet bulb cooling (some
upper 40s over the higher terrain). PoPS were retooled based on
the radar trends with likely and categorical values the next
2-5 hours.

.PREV DISCUSSION [0346 pm EDT]...

A stalled boundary remains draped across Upstate New York. Most
of our area remains on the cooler northeastern side of the
boundary, although some parts of the areas (including the
western Adirondacks, Mohawk Valley, Capital Region and Schoharie
County) are starting to break out in the warmer and more humid
air mass. SPC mesoanalysis shows SBCAPE over 1000 J/kg in CNY,
although this lowers significantly further to the east into
eastern NY, as a stable air mass in place at low levels, thanks
to the marine air that has been in place. Some areas have risen
into the lower 70s, although many spots are still in the 60s
with dewpoints only in the lower 50s. 0-6 km bulk shear is about
30 to 40 kts over the area, although the better shear is off to
the east where instability is much lower.

Radar imagery shows a broken line of showers and thunderstorms
has developed over CNY and these will continue to develop and
spread eastward for later this afternoon and into the early
evening hours. The surface boundary and wave of low pressure
moving along the front will generally stay south of most of the
area, so most of the area should stay in the more stable marine
air. Because of this, the expectation is that these storms will
weaken as they get into our area. We still anticipate some
heavier downpours, lightning and even some small hail, but gusty
winds aren`t expected due to the stable low levels. Far western
areas (western Adirondacks, Mohawk Valley, Schoharie County and
the eastern Catskills) have a low-end chance for some brief
gusty winds and larger hail if they are on the edge of the more
unstable air mass, but this is still a little uncertain and more
of an isolated threat.

CAMs suggest the bulk of the thunderstorm threat will be done by
8 or 9 PM and a few showers could linger towards midnight or
so. The rest of the overnight should be drying out and starting
to clear. Temps will be falling behind the departing storm
system, with lows down into the upper 40s to mid 50s.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
On Wednesday, skies will start off mostly cloudy for much of the
area, but there should be increasing amount of sun through the
day. A weak disturbance sliding by to the north could allow for
a brief shower or sprinkle during the midday hours (mainly for
northern and eastern areas), but this looks fairly isolated. Any
shower would be brief and rather light, as both moisture and
forcing will be limited. Have sided close to the blended
guidance for highs with valley areas in the mid 60s to low 70s
and upper 50s to mid 60s in the high terrain. A few more stray
showers are possible overnight across northern areas with
another disturbance passing by, but overall, any precip looks
light and spotty and most spots will be staying dry. Lows look
to fall into upper 40s to low 50s once again with a partly to
mostly cloudy sky.

Upper level ridging will be starting to build over the area for
Thursday and Thursday night. This should allow for dry
conditions with clearing skies, especially by Thursday night.
Daytime temps look fairly warm thanks to decent mixing and a dry
air mass in place, with valley temps in the 70s. Overnight lows
will generally be in the 40s.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
The extended forecast period begins with tranquil weather, as a mid
and upper level ridge axis is situated over NY and and the Mid
Atlantic Region. H850 temps will be running slightly above normal
based on the latest NAEFS guidance. A sfc anticyclone will be
building in from north-central Quebec.  Max temps will be running
slightly above normal, as we went close to the NBM guidance with
highs in the upper 60s to lower 70s in the valleys and upper 50s to
mid 60s over the higher terrain. The ridge axis should hold on over
NY and New England Fri night with just some high clouds increasing.
Lows fall off into the 40s with some upper 30s over the southern
Greens.

The weekend becomes more unsettled, as a low pressure system and a
warm front approaches from the Great Lakes Region and Ohio Valley.
Clouds increase on Saturday with isolated to scattered showers
especially late in the day. A few thunderstorms may be possible over
the western Dacks. The max temps will trend a little cooler than
normal with more clouds than sunshine with 50s and 60s.  The
boundary becomes occluded with the weak sfc wave Saturday night and
the chances of showers increase, as a broad mid and upper level
trough sets up over central Canada/nrn Plains and the Upper Midwest.
Lows will be mainly in the 40s. The occluded front takes its time
moving over the region with the downstream ridge holding.  A chance
of showers was continued for Sunday into early Sunday night. Max
temps will continue below normal with 50s to lower 60s for highs, as
more clouds than sun prevail.  Partly cloud skies persist Sunday
night with lows mainly in the 40s again.

A brief period of fair weather is expected to open the week with a
sfc anticyclone building in from the Great Lakes Region in the wake
of the front. Temps should rise slightly above normal with west to
northwest flow aloft. The next northern stream disturbance
approaches from the Upper Plains Mon night to Tue along with its
warm front with increasing clouds with the next chance of showers
with perhaps a few thunderstorms. Temps continue slightly above
normal. For the Day 8-14 outlook for the 2nd week of May, CPC is
forecasting above normal temperatures and slightly above normal
precipitation for eastern NY and western New England.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
Through 00z/Thu...A wave of low pressure and a frontal boundary
will widespread showers with an isolated rumble of thunder
across the eastern NY TAF sites prior to midnight with
cigs/vsbys lowering to MVFR levels. The showers will taper in
the early morning hours with low MVFR/IFR stratus setting up.
The IFR stratus will likely be from KALB/KPSF north/northeast
to KGFL. KPOU may hold as low MVFR, but we did add a period of
IFR stratus for KPOU 07Z-14Z/WED.

The stratus will linger most of the morning, but should begin to
break up between 13Z-16Z/WED. We increased the cigs to MVFR
levels in the 1.5-3.0 kft AGL range and to lower VFR at most
KGFL/KALB/KPOU 3.5-5 kft AGL and KPSF may hold as high MVFR in
the 3.0 kft AGL.

The winds will vary in direction at 5 KT or less overnight.
They will increase from the northwest to west at less than 10 KT
during the late morning through the afternoon.

Outlook...

Wednesday Night: Low Operational Impact. Breezy. NO SIG WX.
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: Low Operational Impact. NO SIG WX.
Saturday: Moderate Operational Impact. Slight Chance of SHRA.
Saturday Night: Moderate Operational Impact. Chance of SHRA.
Sunday: Moderate Operational Impact. Chance of SHRA.

&&

.HYDROLOGY...
Showers and thunderstorms last night into this morning produced
some locally heavy rainfall over the Sacandaga and Saratoga
Regions, with up to two inches in some locations. Additional
showers and thunderstorms will spread across the region through
the late evening hours. Most of the activity will probably be
southern areas with this round, but enough northern areas will
see some additional rainfall again for the late day hours. The
low level flow out of the south will bring in plenty of moisture
into the region although dewpoints and PWATs will not be overly
excessive for this time of year.

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 light enough to avoid any flooding of
main stem rivers.

Drier weather will return for Wednesday through the late week.
Although some additional showers are possible from time to time,
amounts are not expected to be excessive and no hydrologic
issues are anticipated through the late week.

&&

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

&&

$$

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