030
FXUS61 KALY 060746
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
346 AM EDT Thu Jun 6 2024

.SYNOPSIS...
Today will be mostly cloudy with showers and thunderstorms
likely, especially during the afternoon and evening. Things
continue to trend cooler and unsettled for Friday through the
weekend, with a chance for showers and a few rumbles of thunder
each afternoon and evening.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Cloudy across the region with the leading edge of some isolated
to scattered showers just to the west, slowly moving toward our
region. The showers will spread to our area through daybreak.
Temperatures will fall slowly to the mid to upper 60s with some
lower 60s higher terrain.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
Tomorrow, the upper low settles over the Great Lakes region,
with a surface cold front and associated wind shift
boundary/pre-frontal trough expected to track through the region
in the afternoon. Guidance is now good agreement that earl AM
showers should diminish by mid morning, which may allow the
atmosphere time to recover and destabilize before another round
of showers and thunderstorms tomorrow afternoon...

CAMs suggest that we may see 500-1000J/kg of CAPE ahead of the
cold front tomorrow afternoon, although exactly how much
instability we see will depend on how much (if any) sun can
break through the clouds tomorrow morning. The best instability
looks to be south of the Capital District, while the best
forcing will be north and west, closer to the upper low.
However, with strong low-level convergence along the wind shift
boundary and 25-30 kt of deep-layer shear, we are expecting to
see a line or cluster(s) of storms tracks across the region from
west to east tomorrow afternoon into early evening. Given the
above parameters, we collaborated with SPC to have a marginal
risk for severe weather across our region. Current thinking is
that the best chance for sever weather will be north and west of
the Capital District, but the intensity of storms will
ultimately depend on how much instability we see.

The other threat with any storms tomorrow, especially during the
afternoon, is for locally heavy rainfall. PWATs look to be at or
above the 90th percentile per the SPC sounding climatology, with
warm cloud depths of 10-11 kft. However, we have been quite dry
lately, and storms should be moving at an "average" pace so they
are not expected to sit in any one place for too long.
Therefore, maximum rainfall amounts look to be more on the order
of 1-2" per the HREF PMM. Finally, flow aloft is relatively
perpendicular to the wind shift boundary, which should help
reduce the risk of training storms. We could certainly see some
ponding of water in the typical urban/poor drainage areas with
any storms, although the threat for more widespread or flash
flooding looks to be on the low side. Highs tomorrow will be
cooler than today, mainly in the 70s and 80s.

Tomorrow evening, thunderstorms come to and end in the evening
as the cold front tracks through our region. There could still
be a few lingering showers overnight with the upper low nearby
over the Great Lakes, but the severe and hydro threats should
end as the sun sets. Behind the front, it will be cooler with
lows dropping into the 50s to around 60s.

Friday through Saturday...The upper low tracks eastwards from
the Great Lakes into southern Canada, just north of the
international border. This will lead to several rounds of
showers and perhaps a few rumbles of thunder, with the best
chance each afternoon and evening with diurnal heating.
Additionally, an secondary cold frontal passage late Friday
afternoon and evening and the left exit region of the upper jet
being overhead Saturday afternoon will enhance coverage of
showers. Instability generally looks unimpressive at <500 J/kg
and the deeper moisture will be off to our east, so severe
weather and/or hydro do not look to be a concern during this
time period. With plenty of clouds and showers around, it will
be much cooler with daytime highs in the 60s to 70s each day and
overnight lows mainly in the 50s, with some upper 40s for the
high terrain.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Long term period will start off cool and unsettled, but we should
see a trend towards drier and slightly warmer weather by the middle
of next week...

Long term period begins at 00z Sunday with the upper low still
centered just north of our forecast area in southern Canada. Where
exactly it tracks Sunday and Monday remains somewhat uncertain, as
we are still seeing some rather large run-to-run jumps with the
various sources of guidance. This makes sense given the tendency for
models to struggle with upper low placement several days out, and we
have therefore taken an ensemble/continuity approach to this portion
of the long term forecast. Even with the uncertainty in the exact
placement of the upper low, this feature is large enough that we
should still be under its influence Sunday with diurnally-driven
scattered showers developing by late morning and lasting through the
evening, with the best chances north of I-90 closer to the cold pool
aloft. A few rumbles of thunder can`t be ruled out, but we are not
expecting any severe weather or hydro concerns. The upper low
finally begins to slide to the east Monday, although a piece of the
upper low may break off and drift southwards over our area. Will
still mention slight chance to chance PoPs Monday, but will note
that coverage of showers will probably be lower than on Sunday. With
plenty of clouds and showers and a cool airmass aloft, daytime highs
Sunday and Monday will range from 60s in the terrain to 70s in the
valleys with overnight lows in the upper 40s (terrain) to 50s
(valleys) each night.

Tuesday and Wednesday...By Tuesday, the upper low should slide
further to our east. Upper ridging builds to the west of our area,
putting us in a drier northwest flow regime. Surface high pressure
builds towards our area from the west, so things should dry out
Tuesday. It will be a few degrees warmer, with highs near normal for
early to mid June. Forecast confidence decreases for Wednesday, as
some sources of guidance show additional upper troughing approaching
from the west while other sources of guidance delay this until later
in the week. So, will mention slight chance to chance PoPs with
temperatures a few degrees warmer than on Tuesday. Looking forward
to days 8-14, the CPC is leaning slightly towards temperatures and
precip being above normal.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
Through 06z Friday...VFR conditions prevail at KALB and KGFL
this morning with MVFR conditions at KPOU and periodic
fluctuations between VFR and MVFR at KPSF. Unfavored flight
conditions come in the form of lowered ceilings as clouds
continue to stream into the region ahead of an approaching
upper-level disturbance. Ceilings will gradually lower at KALB
and KGFL throughout the morning, dropping into MVFR heights
within the next few hours.

KENX radar show showers propagating generally from west to east,
swiftly encroaching upon the region. The terminal to be
impacted first will be KPOU with showers just south of its
vicinity. Showers will then gradually overspread the region over
the next few hours with visibilities possibly dropping to the
MVFR thresholds as well. Breaks in shower activity then comes
later this morning into the early afternoon before thunderstorm
chances increase later in the day. Brief returns to VFR ceilings
are possible before convection this afternoon as hinted at in
the guidance, but with elevated low-level moisture, generally
maintained MVFR conditions throughout the day. Thunderstorms
will be capable of producing heavier rainfall rates that could
result in additional worsening of visibility back to MVFR and
possibly IFR thresholds as well. Upon sunset this evening,
thunderstorms will gradually taper off courtesy of the loss of
daytime heating, but ceilings could remain at the MVFR level for
the remainder of the period.

Winds throughout the 06z TAF period will generally be light out
of the southeast with sustained speeds ranging from 3-6 kt. Some
stronger gusts are possible as a result of thunderstorms this
afternoon.


Outlook...

Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA.
Friday: High Operational Impact. Likely SHRA...TSRA.
Friday Night: Low Operational Impact. NO SIG WX.
Saturday: High Operational Impact. Likely SHRA...TSRA.
Saturday Night: Moderate Operational Impact. Chance of SHRA...TSRA.
Sunday: Moderate Operational Impact. Chance of SHRA...TSRA.
Sunday Night: Low Operational Impact. Slight Chance of SHRA...TSRA.
Monday: Moderate Operational Impact. Chance of SHRA...TSRA

&&

.HYDROLOGY...
Showers and scattered thunderstorms are expected late tonight
through Thursday. Rainfall amounts of around 1 inch are expected
with localized amounts up to 2 inches. Some thunderstorms will
contain heavy rain and could produce localized ponding of water
on roadways, urban and small stream flooding and standing water
in low lying areas.

No flooding of main stem rivers is expected. Additional showers
and thunderstorms will occur Friday through the weekend but
less widespread and lighter, with additional amounts of perhaps
up to a half inch of rain through the weekend.

&&

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

&&

$$

SYNOPSIS...NAS
NEAR TERM...NAS
SHORT TERM...Main
LONG TERM...Main
AVIATION...Gant
HYDROLOGY...NAS