503
FXUS61 KALY 131955
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
355 PM EDT Thu Jun 13 2024

.SYNOPSIS...
Dry weather is expected through the first half of tonight, but there
is a chance for showers and thunderstorms tomorrow mainly during the
afternoon and evening. A few storms could be strong to severe south
and east of the Capital District. Then, cooler and drier weather
returns for the weekend. Temperatures warm up significantly heading
into next week, with temperatures and humidity potentially
approaching dangerous levels Tuesday through Thursday.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 3:55 PM EDT...Flat upper ridging remains over our region,
with surface high pressure located well to our east over the
Atlantic. South/southwest flow around the high and warm
advection have lead to daytime highs climbing into the mid 80s
for many valley areas under partly to mostly clear skies.
Additionally, a surface low is now developing to the north of
the Great Lakes in association with a potent upper shortwave...

Tonight, the surface low deepens to sub-990 mb as it and the
upper shortwave track north of the Great Lakes into eastern
Canada. Ahead of these features, a weak upper impulse and pre-
frontal trough will cross our region, potentially leading to a
few showers and possibly an embedded thunderstorm across the
Adirondacks. Coverage of showers and thunderstorms gradually
spreads further south and east the second half of the night,
with a few showers potentially getting to the Capital District
around sunrise. With increasing clouds and winds remaining
light, it will be on the warmer side with lows mainly in the
60s.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
By tomorrow morning, the surface low will be located well to our
north, with the trailing cold front approaching from the west. A
second upper impulse will help drive this cold front
southeastwards through our region tomorrow, which will result in
showers and thunderstorms developing across the region. With a
warm and relatively moist airmass ahead of the front, a few of
these storms could be strong to severe with SPC having placed
areas mainly south and east of Albany in a slight risk for
severe storms. Highs will be mainly in the upper 70s north and
west of the Capital District, with mid 80s possible in the Mid
Hudson Valley and western CT.

With the approaching cold front, upper shortwave, and the right
entrance of the upper jet nearby, there will be decent forcing
for ascent so showers should be fairly widespread tomorrow
afternoon. Regarding the severe potential, the HREF mean
suggests SBCAPE values of up to 1000-1500 J/kg overlapping with
30-40 kt of deep-layer shear. The shear profile is relatively
top-heavy, but should still be sufficient for some organized
convection. Any initially discrete cells should grow upscale
into a line or line segments with the relatively strong forcing
and unidirectional shear profile. With low-level dry air and
relatively steep low-level lapse rates, damaging winds look to
be the main threat with storms, but straight to slightly
counterclockwise turning hodographs and strong storm-relative
flow aloft also suggest the potential for a few storms to also
contain large hail, especially before convection congeals into a
line. The best chance for any severe storms looks to be from
around noon through 00z, again focused south and east of the
Capital District. One potential "failure mode" for severe
weather is if morning showers/non-severe convection end up
tracking further south and east than currently expected. If the
morning showers make it south and east of the Capital District,
then the risk for severe weather later in the day would be
lower.

Locally heavy rain is also possible with any
storms, but with PWATs "only" around 1.5 inches, progressive
storm motions, and dry antecedent conditions we are not
expecting widespread hydro issues. Of course, the typical
nuisance urban/poor drainage flooding is always possible should
any of these heavier rainfall rates move over any urban areas.

Showers and storms may linger into the evening tomorrow, but
should come to an end between 00z and midnight. Things should
dry out behind the cold front, with cooler and drier air being
advected into the region. Lows will be in the upper 40s for the
ADKs to mainly 50s elsewhere.

Saturday and Sunday...We remain in a cool/dry advection regime
behind the cold front, with surface high pressure building into
the region with northwest flow aloft. It will be much cooler on
Saturday with highs in the 60s for the terrain to 70s in the
valleys. With the high directly overhead Saturday night, it will
be quite cool with most areas dropping into the 40s and even a
few upper 30s possible in the high terrain. Sunday remains dry
but will be slightly warmer with highs mainly in the 70s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Long term period begins Sunday night with surface high pressure
sliding off the east coast of New England. A warm front will lift
northeastwards across the region late in the overnight period, so
lows will be a few to several degrees warmer than the previous night
with lows in the 50s to around 60. Monday, we get into
south/southwest return flow and warm advection around the periphery
of the upper high. Upper ridging begins to build over the eastern
half of the CONUS, so it will be quite a bit warmer than the
previous couple days with highs in the mid 80s.

This will be the start of a significant warming trend, as the upper
ridge continues to amplify over the eastern US through the middle of
next week. Ensemble guidance is in good agreement that most of our
area will be within the 594 dam contour, with some deterministic
guidance suggesting we may see 600 dam heights at 500 mb somewhere
in the Mid Atlantic or Northeast. 850 mb temperatures climb into the
low 20s Celsius, which will translate to surface temperatures in the
90s for many of our valley areas each day Tuesday through Thursday.
With dew points well into the 60s each day, afternoon heat index
values are may potentially reach or exceed 100 degrees for many
valley areas Tuesday through Thursday. Heat advisories will
likely be needed as we get closer to this event, with excessive
heat warnings not completely out of the question. Overnight lows
will be in the upper 60s to around 70, so even at night it will
remain quite warm and muggy.

Forecast confidence is relatively high that we will see
hot/humid weather next week, although just how hot it gets
remains somewhat uncertain. One potential factor that could
lower temperatures slightly is an upper shortwave that will be
tracking around the northern periphery of the ridge sometime
Monday or Tuesday. All sources of guidance have this feature,
although they differ on its track and timing. Where this feature
tracks, there will be a few more clouds with isolated to
scattered afternoon showers and thunderstorms, which could
locally reduce temperatures. At this point, the greatest chance
for a few showers or thunderstorms looks to be mainly north of
I-90. Even if the "cooler" scenario were to play out, we would
still likely see many areas reach or exceed heat advisory
criteria Tuesday through Thursday. Confidence decreases for the
middle and end of next week with most sources of guidance
suggesting the ridge will break down at some point, but it is
too soon to tell exactly when this will happen. The CPC is still
expecting temperatures to average above normal for the 8-14 day
timeframe.


&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
Through 18z/Fri...VFR conditions will remain in place into this
evening with some fair weather cumulus and high cirrus around. A
cold front will slowly approach the region overnight into Friday
morning. A few rain showers may develop ahead of the front prior to
daybreak near KALB/KGFL and near or after daybreak at KPSF.
Cigs/vsbys may remain in the VFR range within these showers. Showers
and thunderstorms are expected to develop between 16-18z/Fri, mainly
affecting KALB/KPSF/KPOU. With the timing of these showers closer to
the end of the current TAF period, will refer to later TAF issuances
for further details.

Wind will be south to southwesterly at around 10 kt this afternoon
into this evening before decreasing to less than 10 kt tonight into
Friday morning (except remaining around 10 kt at KALB).

Outlook...

Friday Night: Low Operational Impact. Slight Chance of SHRA...TSRA.
Saturday: No Operational Impact. NO SIG WX.
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: No Operational Impact. NO SIG WX.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.

&&

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

&&

$$

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