401
FXUS61 KALY 080142
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
942 PM EDT Tue May 7 2024

.SYNOPSIS...
After a warm and dry day today, there will be several
chances for rain through this weekend. A few thunderstorms are
possible late tonight and tomorrow, and a couple storms tomorrow
afternoon could be on the stronger side. After another warm day
tomorrow, temperatures trend cooler for the end of the week.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
As of 941 PM EDT...Surface high pressure continues to be
located over the Northeast. Meanwhile, a warm front is located
south of the region over the Ohio Valley and northern mid
Atlantic States. This warm front will be trying to head towards
the area for later tonight.

IR satellite imagery and surface observations are starting to
show increasing amounts of cirrus clouds across the region.
Based on the latest model trends, dry weather continues through
the first half of tonight. With only thin clouds initially
and light winds, temperatures should drop off fairly quickly,
but will level off after midnight as cloud cover increases and
winds pick up. Overnight lows will likely end up in the 40s to
50s. The upper ridge weakens as it moves overhead tonight, and
an upper low tracks into the Great Lakes. This feature will be
associated with an area of low pressure at the surface, and will
be responsible for quite a bit of convection upstream
overnight. As the system`s warm front approaches our region late
tonight, this convection will move into our area between 7-10z
from west to east, bringing chances for showers and possibly a
few rumbles of thunder with forecast soundings showing a few
hundred joules of elevated cape. However, with a low-level
inversion in place, the convection should remain elevated and
thus severe weather does not look to be a concern overnight
tonight despite increasing shear as the low-level jet
strengthens.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
Forecast for tomorrow remains complicated, with a chance for
some stronger storms...The day begins with the surface warm
front continuing to lift northwards through our region. There
will likely be lingering convection around to start the day
associated with this warm front, especially north of I-90. Then,
later in the afternoon, the upper low will open up as it tracks
through upstate NY. The system`s cold front will track through
tomorrow evening, pre-frontal trough will track through the
region tomorrow afternoon.

Behind the warm front, we should get into the warm sector with
temperatures climbing well into the 70s, especially for areas
along and south of I-90. With steep mid-level lapse rates in
excess of 7C/km, this will lead to SBCAPE values approaching
1000 J/kg, with some pockets of locally higher values possible
in the Mid Hudson Valley and western New England. Deep-layer
shear also increased to 60-70 kts. While this parameter space
is fairly impressive for our area, the best upper forcing will
remain to the north and will not overlap with the best
instability/shear. The best chance for any stronger storms
appears to be across the Mid Hudson Valley, western MA, and
western CT with any storms that develop with/ahead of the pre-
frontal trough. Therefore, it looks like a fairly narrow window
from very late morning through mid-afternoon where storms are
possible. With mean flow perpendicular to the low-level forcing,
and weak upper forcing, some discrete storms could develop in
these areas ahead of the pre-frontal trough. The severe threat
is conditional on convection initiating, but if any storms do
develop the primary threats look to be gusty winds with
steepening low-level lapse rates and mid- level drying. Mid-
level dry air and long, straight hodographs also indicate the
possibility of hail with any discrete storms that develop.
Accordingly, SPC has placed our area in a marginal risk for
severe weather tomorrow.

Behind the pre-frontal trough, winds shift to
the west and drier low and mid-level air gets advected into the
region, which will reduce instability and make convective
initiation more difficult. A few additional showers/storms are
possible later in the evening for the Mohawk Valley/western
Adirondacks ahead of the true cold front, but the severe threat
looks more limited at this time with waning instability due to
drier air and loss of daytime heating.

Tomorrow night, lingering showers/thunderstorms come to and end
in the evening/early in the overnight period as heights rise
aloft. The cold front drops southwards across the region, but
may not make it all the way to our southern border with OKX. For
areas behind the front, northwesterly winds advect cooler and
drier air into the region. Lows will generally be in the 40s
(north) to 50s (south). Some patchy fog can`t be ruled out
either, especially ahead of the cold front.

Thursday through Friday...Thursday starts off dry but rain
chances increase through the day. A broad, positively tilted
upper trough will approach the Great Lakes, and there will be
numerous upper shortwaves rotating around this upper trough. At
the surface, an area of low pressure will track from the Ohio
Valley off the Mid-Atlantic coast, bringing increased chances
for showers to the region tomorrow afternoon through Friday. Due
to the amount of small-scale shortwaves, there is quite a bit of
forecast uncertainty, more than would be expected at this lead
time. The best chance for showers will be for areas along and
south of I-90, although some sources of guidance suggest showers
could make it much further north. Chances for showers continue
through Thursday night and into Friday, with a secondary surface
low potentially tracking towards our region Friday. Will attempt
to refine the timing and amount of precipitation over the
coming days with guidance hopefully coming into better
agreement. Daytime highs Thursday and Friday will be much
cooler than the previous few days, with overnight lows in the
40s to around 50 Thursday night. Severe weather is not expected
during the Thursday through Friday timeframe.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Unsettled and cool conditions describes the weather pattern for
the upcoming weekend as a long wave trough remains positioned
over the Eastern CONUS with a series of shortwaves tracking
from the Midwest into the Northeast. After showers Friday night,
some brief ridging and subsidence aloft ensues for at least the
first half of Saturday which should support a dry break.
However, an additional shortwave from the Ohio Valley will
provide enough lift to support showers returning Saturday
afternoon into Saturday night. The shortwave lingers overhead
through Sunday with sufficient mid-level moisture and some weak
warm air advection as winds aloft shift to the south or
southeast. This set-up will maintain chance POPs through the day
with even a slight chance for thunderstorms as some instability
may sneak northward. While temperatures Saturday remain cooler
than normal with highs only in the 50s to low 60s thanks to
west-northwest flow aloft, temperatures should trend a bit
milder for Sunday rising into the low to mid 60s in the valley
with mid to upper 50s in the higher terrain and hill towns.

There remains some uncertainty on how the pattern evolves for
Monday into Tuesday as weak shortwaves continue to track aloft
while weak high pressure builds at the surface. Therefore, we
maintained low end chance POPs for Monday into Tuesday but this
may change as guidance becomes into better agreement. Despite
the uncertainty in the evolution of shortwaves aloft, there is
better agreement for temperatures to trend milder and more
seasonable as a milder air mass from the Ohio Valley spills
eastward.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
Flying conditions are currently VFR with a mostly clear sky in
place. Through the late evening hours, it will continue to be
VFR with just some thin cirrus. Winds will become light and
variable or calm for most areas after sunset.

After midnight, clouds cover will begin to lower and thicken
across the region, as a warm front starts to approach. The
frontal boundary will allow an area of showers to spread towards
the area for the late night hours (after 9z). A stray rumble of
thunder can`t be ruled out with this activity, but thunder with
this looks isolated at this time. Within this batch of moderate
rainfall, flying conditions may lower to IFR, as visibility
looks to drop towards 2 SM within these showers. This precip
will last a few hours, but will be ending 13-15z for all sites.

Behind this initial batch of rain, there will be a few hours
where low clouds will keep MVFR cigs around, with ceilings
around 1500-3000 ft. By the early to mid afternoon hours, there
should be enough break of sun to allow for VFR conditions to
return to all sites, with just sct-bkn cigs around 5-7 kft.
However, another round of scattered showers and possible
t-storms can`t be ruled out for the afternoon into the early
evening hours. Some of these storms could be strong with gusty
winds, but coverage is still in question at this time. Will
include a PROB30 for t-storms at all sites. Once this clear
through, winds will become westerly around 10 kts with clearing
skies and flying conditions remaining VFR into Wed night.

Outlook...

Wednesday Night: Low Operational Impact. Slight Chance of SHRA...TSRA.
Thursday: Moderate Operational Impact. Likely SHRA.
Thursday Night: High Operational Impact. Likely SHRA.
Friday: High Operational Impact. Likely SHRA.
Friday Night: Moderate Operational Impact. Chance of SHRA.
Saturday: Moderate Operational Impact. Chance of SHRA.
Saturday Night: Low Operational Impact. Slight Chance of SHRA.
Sunday: Moderate Operational Impact. Likely SHRA.

&&

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

&&

$$

SYNOPSIS...Main
NEAR TERM...Frugis/Main
SHORT TERM...Main
LONG TERM...Speciale
AVIATION...Frugis