307
FXUS61 KALY 140550
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
150 AM EDT Fri Jun 14 2024

.SYNOPSIS...
A swift-moving cold front will track through the region
today, bringing showers and thunderstorms, some of which could be
strong to severe south and east of the Capital District. High
pressure behind the front will then ensure a beautiful, dry weekend
before a significant warm up is expected next week.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
.UPDATE...A band of showers has moved into Herkimer and Hamilton
Counties this evening, bringing light to potentially moderate
rainfall rates in these areas. Though some embedded rumbles of
thunder were once associated with these convective showers, a
general lack of instability has lead to the weakening of storms.
Adjusted PoPs and sky cover to account for latest trends in
shower activity. Also made minor adjustments to temperatures to
reflect latest obs. Other than that, the forecast remains within
good shape with this update. See the previous discussion below
for additional details on the overnight forecast.

.PREVIOUS DISCUSSION...
As of 950 PM EDT... Flat upper ridging remains over our region,
with surface high pressure located well to our east over the
Atlantic. To the west, a frontal boundary is making its way
across the Great Lakes and Ontario, with a surface low lifting
northward across southern Canada. Ahead of this front, there is
a prefrontal surface trough as well.

MRMS imagery and lightning data shows a well developed line of
showers and thunderstorms over eastern Ontario. Some scattered
showers and embedded thunderstorms also extend eastward across
southern Quebec. A few showers were even impacting the North
Country and parts of the Adirondacks earlier, but these have
mostly dissipated and/or lifted off to the northeast.

CAMs suggest that line of showers and thunderstorms over Canada
will be pushing eastward through the late evening hours and
will be spreading towards the US border for tonight. However,
the convection will be getting too far ahead of the surface
boundary and will be weakening thanks to the loss of daytime
heating. As a result, the majority of these showers and
thunderstorms will fall apart as they get into our area. Still,
a brief shower or isolated t-storm can`t be ruled out for the
late night hours for northern areas. It`s even possible that a
few showers potentially getting to the Capital District around
sunrise, although this is rather uncertain and there may not be
much left of this activity by then.

Otherwise, skies will remain partly to mostly clear across our
area through the overnight hours. Some passing high clouds ahead
of the decaying convection looks to pass through, but limited
other clouds are expected. There should be a persistent light
southerly breeze through the night as well. It will be on the
warmer side with lows mainly in the 60s, which will be milder
compared to the past few nights.

&&

.SHORT TERM /6 AM THIS 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 /06Z FRIDAY THROUGH TUESDAY/...
Line of weakening showers in northern NY is gradually dropping south
and some of the showers will approach KGFL by 08Z and KALB by about
10Z. Predominant conditions will still be VFR because the showers
should weaken considerably and become more scattered.

A new line of showers and scattered thunderstorms is expected to
develop after about 15Z near or just south and east of KALB. Other
showers will for around KALB and including showers with MVFR
conditions between about 15Z-19Z at KGFL and KALB. As the
thunderstorms develop in the afternoon, including a brief period of
thunder at KALB between 20Z-21Z, that will likely be shifted either
earlier or later, depending on the actual observed storms later
today.

The best coverage and duration of showers and storms is expected at
KPOU and KPSF, where thunderstorms are included between about 20Z-
23Z with MVFR conditions. Some brief bursts to IFR are possible in
the heaviest rain but too brief to include in TAFs.  By 22Z-24Z,
rain exits KALB and KGFL, while some showers could linger at KPOU
and KPSF until around 02Z-03Z. VFR conditions expected once the
showers and storms exit this evening.

Steady south winds through this morning at 10 Kt or less, with a
gust around 15 Kt at times at KALB and KPSF. Thunderstorms could
have gusts to 35 Kt this afternoon. Winds shift to west and
northwest this afternoon at 10 Kt or less and continue this evening.


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...Gant
NEAR TERM...Frugis/Gant
SHORT TERM...Main
LONG TERM...Main
AVIATION...NAS