847
FXUS61 KALY 291751
AFDALY

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

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

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 151 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
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
stationary, perhaps briefly settling southward this evening
towards the lower Hudson Valley.

While there had been some showers earlier this morning over
nothern areas, all precip has ended. Radar trends and CAMs
suggest it should stay dry through the rest of the day, although
some showers may start to develop towards evening for locations
south and west of the CWA.

With the boundary across the area, there will continue to be a
big spread in max temps for this afternoon. Across areas north
of the front, temps are generally expected in the 50s to low
60s for these areas. It will remain milder for far southern
areas through the day. Although it`s been cloudy so far today, some
more breaks of sun are possible by afternoon for the Capital
Region, although it`s unclear if this sun will be able to make
much of a difference after the cool and cloudy start on the
backside of the front.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
Low level ridge axis shifts east of our region and west to
southwest boundary layer flow spreads through the region.
Stronger warm advection and moisture advection along with
increasing low level convergence will result in weak instability
in our region by late this afternoon and evening. Better
instability in PA and central NY could support development of
some showers and isolated thunderstorms where the thermal and
moisture gradient is a little tighter along the leading edge of
the warm advection. Sources of guidance show a general consensus
for some of that rain to track into our region tonight but
coverage is very much in question. So, including scattered
showers and isolated thunderstorms tonight, until we see what
develops this afternoon and can track it.

Upper energy tracking through the flat upper ridging in the
eastern U.S. will weaken as it tracks across northern areas
Tuesday through Wednesday. The associated leading edge of low
level cold advection and wind shift is expected to track through
our region Tuesday afternoon and evening. Some instability in
our region, especially from the eastern Catskills through mid
Hudson Valley and NW CT, will support showers and isolated
thunderstorms. There are some signals that midlevel lapse rates
could be somewhat steep in those areas. So, we will have to
keep an eye on some potential for stronger thunderstorms there.
Isolated thunderstorms are possible across the entire region but
again, the potential stronger thunderstorms could be in
southern areas. Highs Tuesday in the 60s to around 70, but
warmer if there are some persistent breaks in the clouds in the
morning and early afternoon.

The upper energy and associated cold front will be slow to exit
and showers and isolated thunderstorms will linger into Tuesday
night. Clouds and some isolated showers could linger into
Wednesday morning, with clouds slow to break up through
Wednesday. There are disagreements in sources of
guidance/ensembles for rain chances Wednesday afternoon and
night as warm advection begins again and strengthens with
increasing low level forcing and moisture. The majority of
guidance suggests isolated showers at best and the upper pattern
and wind flow supports the more isolated activity at best. Highs
Wednesday in the mid to upper 60s, with some lower 60s in higher
terrain. Lows Wednesday night in the upper 40s to lower 50s.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Long term begins at 12z Thursday with upper ridging amplifying to
the west of our area and surface high pressure off to our north and
west. Most sources of guidance suggest a fairly potent upper
shortwave will ride up and over top of the ridge Thursday, although
its exact track in relation to our forecast area remains somewhat of
a question. The current consensus is for this feature to track north
and east of our region. This could result in a few showers for the
upper Hudson Valley into western New England. However, a track
further south would result in showers spreading further southwest
into our CWA. There may also be a relatively tight thermal gradient
that sets up across our region, with temperatures well into the 70s
for the Mid Hudson Valley yet only in the low 60s across portions of
VT, especially in the higher elevations.

As this shortwave moves off to our east Thursday afternoon and
evening, the upper ridge continues to amplify through Friday night
as it slowly shifts eastwards over our region. A ridge of high
pressure at the surface will build southwards into our region, and
subsidence associated with these features should result in mainly
dry conditions Thursday night through Friday night. Lows will be in
the 40s to 50s Thursday and Friday nights with highs Friday a degree
or two cooler than those on Thursday.

The next chance for precipitation comes over the weekend as a
vertically stacked surface low tracks from the upper Midwest into
Canada and its occluded front approaches from the west. There is
still some uncertainty on how quickly an occluded front tracks into
the region and thus how quickly precip moves in. Given the
uncertainty, have gone near NBM guidance which brings chance PoPs
into the region Saturday, although given the upper ridging overhead
and the fact that the best upper forcing is well off to our west
would not be surprised to see a slower Euro-like solution verify. If
this were indeed the case, much of Saturday could be dry with better
chances for showers on Sunday. If the frontal passage coincides with
peak daytime heating, then a few rumbles of thunder would also be
possible. Temperatures over the weekend generally be in the 60s for
daytime highs and 40s to 50s at night. For days 8-14, the CPC is
expecting below normal temperatures and near normal precip.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
Flying conditions are generally VFR for the valley sites, with
MVFR ceilings at the higher elevation site of KPSF. A frontal
boundary is located close to the region and this front will
remain stalled over the area through the late evening hours,
before returning back northward as a warm front for the
overnight hours. While it should stay dry through this evening,
some showers may develop along this front overnight, although
activity will be fairly spotty. A light northerly wind through
this evening with become easterly at light speeds for the
overnight. Some additional showers or thunderstorms may be
possible on Tuesday, although it may not be until late in the
day (after the TAF period ending at 18z Tuesday).

Based on model soundings, will be expecting low stratus to
re-develop overnight as the front lifts northward. Will allow
for MVFR ceilings for all sites for the overnight hours, with
ovc cigs around 2-3 kft. On Tuesday morning, flying conditions
will continue to remain MVFR for all sites, with a moist
southeasterly winds developing at 5 to 10 kts for all TAF sites.

Outlook...

Tuesday Night: High Operational Impact. Likely SHRA...TSRA.
Wednesday: Moderate Operational Impact. Chance of SHRA.
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: Low Operational Impact. Slight Chance of SHRA.
Thursday Night: No 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
NEAR TERM...Frugis
SHORT TERM...NAS
LONG TERM...Main
AVIATION...Frugis
HYDROLOGY...Frugis