592
FXUS61 KALY 230817
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
417 AM EDT Sun Jun 23 2024

.SYNOPSIS...
Today will be hot and muggy with showers and thunderstorms this
afternoon, some of which may be severe. Tomorrow is much cooler
although we will still have scattered showers around, especially for
northern areas. We warm up again towards the middle of the week with
additional chances for showers and storms with a mid-week cold
frontal passage.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 4:15 AM EDT...A warm frontal boundary remains draped
across our region north of I-90, and we continue to see
scattered showers and thunderstorms along this boundary due to
enhanced low-level convergence and several upper impulses
tracking along the frontal zone. While vertical wind shear
remain impressive across our northern areas, instability is
lacking at this time of night, so we do not anticipate that
these showers and storms will be severe through the next few
hours. The remainder of the night will be warm and muggy, with
lows only in the mid 60s to around 70. There will also be patchy
fog and low stratus around that should burn off later this
morning.

Today looks like quite an active weather day across eastern NY
and western New England. The 999 mb low currently located over
the Great Lakes region will intensify today as it tracks in
tandem with a potent upper shortwave along the International
Border. This will help to lift the warm front north of our
region this morning. This will put our region in the system`s
warm sector, with temperatures in the upper 80s to low 90s for
some valley areas along with oppressive humidity. For the Hudson
Valley from the Capital District southwards, and for Litchfield
County, a Heat Advisory remains in effect through 8 pm this
evening as heat index values are expected to reach 95-100
degrees. This afternoon, a pre-frontal trough ahead of the
system`s cold front will track through the region, helping to
spark scattered showers and storms, some of which will likely
become severe...

CAMs are suggesting an impressive parameter space of cape and
shear across our region today. There are some questions as to
just how much instability we see with lots of morning cloud
cover, but the HREF mean suggests that most of our area should
see around 1500 J/kg of MLCAPE with pockets of 1500-2000 J/kg in
the Hudson and CT River Valleys. Low-level and deep-layer shear
look quite impressive with the southwesterly LLJ at 850 mb
increasing to 30-40 kts this afternoon, with 45-50 kt of W/SW
flow at 500 mb. This will set the stage for all modes of severe
weather today. SPC has placed our region in a slight to enhanced
risk for severe weather. Damaging winds will be the primary
threat, and are possible with any stronger storms. While SPC has
the highest wind probs in VT and the Berkshires, more breaks of
sun and deeper mixing in the Mid Hudson Valley suggests there
could be a higher threat for damaging winds there as well. With
impressive shear in place, we will likely see some supercell
structures, especially with any discrete cells. The highest
chance is in the enhanced risk area, closer to the warm front.
This is also the most likely area where there could be a couple
of tornadoes, as LCLs are lower here and SRH is higher, on the
order of 100 to 200 m2/s2. Some low-level curvature to the
hodographs indicates the presence of streamwise vorticity in the
low-levels of the atmosphere, and 0-3 km MLCAPE values of 100 to
200 J/kg all indicate an environment supportive of a few
tornadoes. Any stronger storms and certainly supercells will
also be capable of producing large hail.

Heavy rain leading to isolated flash flooding will also be an
issue, as PWAT values remain quite high at 1.8-2". Most areas
have seen rain over the past few days so the ground is not as
dry as it was earlier in the week. However, storms will be
moving faster than the last few days which will help mitigate a
more widespread hydro threat. Timing for severe storms looks to
be primarily from early this afternoon through this evening.
There is some question about the coverage of storms given that
the best upper and lower-level forcing remains to our west until
after dark, but CAM simulated radar reflectivity may be
underdone as CAMs can sometimes underestimate coverage of storms
in the warm sector. Overall ,greatest threat window for severe
weather is from early afternoon through this evening. A second
round of storms is possible late this evening/early tonight
ahead of the true cold front, and while a few of these may
remain on the strong side the severe threat should begin to
subside by sunset.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
Tonight, there will likely be some lingering showers and
thunderstorms into the overnight period. Coverage of showers and
storms should diminish after midnight with the passage of the
cold front. Temperatures remain on the warm and muggy side as
the cooler air won`t arrive until closer to daybreak, with lows
mainly in the 60s.

Tomorrow, the upper trough and cold pool aloft moves overhead.
We will likely have some scattered showers and a few
thunderstorms, especially across norther areas closer to the
upper deformation, although we are not expecting severe weather
or hydro concerns at this time. It will be much cooler and less
humid with highs in the 60s(terrain) to 70s (valleys) and dew
points in the lower 60s. We dry out Monday night as surface high
pressure builds in from the southwest with lows dropping mostly
into the 50s with a few 40s in the high terrain. We warm up
Tuesday as the high slides to our southeast and we get into a
warm advection regime, but the humidity remains at bay. Dry
conditions are expected Tuesday and Tuesday night, although
overnight lows will be warmer again, with 60s for most areas.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
The extended forecast period opens with nearly zonal flow aloft with
a mid and upper level trough approaching from the Great Lakes Region
and southern Ontario.  The air mass over the forecast area becomes
more humid and unstable with sfc dewpoints well into the 60s.  A pre
frontal trough and a cold front will bring scattered showers and
thunderstorms to the region.  Depending on the amount of instability
and sfc heating, some of the storms may be on the stronger side.
PWATs rise 1 to 2 STDEVs above normal based on the latest NAEFS.
Some locally heavy rain will be possible.  Max temps will range from
the mid 80s to lower 90s in many of the valley areas with the best
chance of lower 90s in the mid Hudson Valley.  Some apparent
temps/heat indices may reach the mid and upper 90s from the Capital
District south down the Hudson River Valley and the southern
Taconics.  Heat Advisories may be needed later in time.  Temps will
be in the 70s to lower 80s over the higher terrain.  The showers and
thunderstorms continue into the overnight and begin to taper between
06Z-12Z/THU.  The cold front will each eastern New England. Lows
will fall back into the 50s to lower 60s over the higher terrain and
lower to upper 60s in the valleys.

Thu through Fri night...A few showers are possible with the upper
trough passage and in the wake of the cold front from the Taconics
eastward into western New England early Thu. A cooler and drier air
mass will be ridging in during the afternoon from the Great Lakes
Region. Temps will be near seasonal levels with upper 70s to lower
80s below 1000 ft in elevation and 60s to mid 70s above it. A cool
and pleasant night is expected Thu night with lows mainly in the mid
40s to mid 50s over the region.  A 1020 hPa or so sfc anticyclone
settles over southern Quebec, NY and New England on Friday with fair
and dry weather continuing to close the week. Max temps will be
near seasonal normal for late June with comfortable humidity
levels. The sfc high moves east of Maine Fri night. Some mid and
high clouds may increase overnight with lows in the 50s to
lower 60s.

The weekend opens with a warm front approaching from lower Great
Lakes Region and Pennsylvania  which will increase clouds and
humidity levels with isolated to scattered showers and thunderstorms
moving in during the day. Temps rise back slightly above normal
with mid 70s to mid 80s across the forecast area. CPC is
predicting temperatures above normal for Days 8-14 (June 30th to
July 6th) with precipitation slightly above normal for eastern
NY and western New England.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
Through 06Z MON...a warm front will move across the region this
morning with isolated to scattered showers and thunderstorms.  A
prefrontal trough and cold front will move across eastern NY and
western New England this afternoon through tonight with some strong
to severe thunderstorms and scattered showers.

Conditions vary from IFR levels at KGFL/KPSF this morning with cigs
500-900 ft AGL with vsbys MVFR to MVFR/VFR levels at KALB/KPOU.
Expecting widespread IFR/low MVFR cigs to continue this morning as
the warm front slowly lifts northward.  Some showers or isolated
thunderstorm can not be ruled out.  The vsbys may briefly dip to IFR
levels at KGFL/KPSF.

The mist/stratus should burn off between 12Z-14Z/SUN at the majority
of the TAF sites with it perhaps lingering at KPSF with MVFR cigs
until 16Z/noon.  A pre frontal disturbance may quickly fire some
strong to severe thunderstorms between 16Z-19Z near KGFL/KALB and
then 18Z-21Z for KPSF/KPOU.  We used 5 or 6 hour PROB40 groups to
focus on these potential strong to severe thunderstorms with wind
gusts to 35 KT and IFR vsbys and MVFR cigs.

VFR/MVFR conditions may return 22Z/SUN to 01Z/MON in the wake of the
first disturbance.  A cold front will approach for the nighttime
period and we placed VCSH groups to later refine the
shower/thunderstorm threat tonight with later TAF issuances.

Winds will be light and variable in direction at 6 KT or less or
calm.  The winds become south at 10 to 15 KT in the late morning
into the afternoon with some gusts 20-25 KT.  Winds veer to the
south/southwest tonight at 8-15 KT.

The winds may vary in direction or be gusty to 25-40 KT with any
thunderstorm.

Outlook...

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

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory until 8 PM EDT this evening for CTZ001-013.
NY...Heat Advisory until 8 PM EDT this evening for NYZ064>066.
     Heat Advisory from 11 AM this morning to 8 PM EDT this evening
     for NYZ049-050-052-053-059-060.
MA...None.
VT...None.

&&

$$

SYNOPSIS...Main
NEAR TERM...Main
SHORT TERM...Main
LONG TERM...Wasula
AVIATION...Wasula