083
FXUS61 KALY 121120
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
720 AM EDT Wed Jun 12 2024

.SYNOPSIS...
Upper-level low and associated trough continue to push
east throughout the day today, yielding breaks in cloud coverage.
Dry weather can be expected through Thursday before the chance for
showers and thunderstorms increases Thursday night through Friday
courtesy of an approaching cold front. A dry, seasonable weekend
then gives way to a possible stretch of unseasonable warmth for the
beginning into the middle of next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
.UPDATE...As of 655 AM, only minor adjustments were needed to
ensure temperature and sky cover consistency with latest obs and
trends. Otherwise, the forecast remains in good shape with this
update. See the previous discussion below for additional
details on today`s forecast.

.PREV DISCUSSION [0500 AM EDT]...Infrared satellite imagery
indicates a fairly consistent layer of lower-level stratus
painting the sky across much of eastern New York and western New
England this morning as our persistent upper-level low and
associated trough linger overhead. Temperatures are subsequently
fairly variable with upper 40s to low 50s where breaks in cloud
coverage have contributed to decent radiational cooling and
mid/upper 50s and even pockets near 60 where coverage has
remained more consistent.

Throughout the day today, the upper-level system will continue
to slide towards Atlantic Canada, allowing near- zonal flow to
begin to take hold of the region. Breaks in cloud coverage are
expected later this afternoon and into this evening as cyclonic
flow weakens and mid- level dry air increases. However, partly
to mostly cloudy skies will persist early this morning into
early this afternoon as a shortwave disturbance rotates about
the southern periphery of an upper-low currently located just
south and west of the Hudson Bay.

Conditions throughout the day today should remain primarily dry,
though a stray upslope shower or two is possible in the
Southern Greens and Southern Adirondacks as the aforementioned
upper-low progresses further north and east. Breaks in the
clouds will help temperatures rise into the upper 60s to low 70s
at higher elevations and mid to upper 70s in valley areas.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
Atmospheric heights gradually rise this evening into tonight as
the aforementioned upper-low continues to pull away from the
region and weak ridging builds in aloft. Dry conditions will,
therefore, be sustained through the overnight period tonight
with skies becoming mainly clear. A favored environment for
radiational cooling, low temperatures tonight will fall into the
upper 40s to low 50s with pockets of mid 50s in the Mid- Hudson
Valley and mid 40s above 1500 ft.

Dry conditions persist into Thursday as high pressure dominates
at the surface and heights aloft remain relatively stagnant.
Flow aloft gradually backing to the southwest will aid in
ushering in a warmer airmass than previous days with 850 mb
temps increasing to +14 to +16 C. This, paired with mainly
clear skies through peak heating hours, will support highs in
the upper 70s to mid and possibly upper 80s in valley areas.
However, clouds will be on the increase once again beginning
Thursday afternoon as an upper-level trough approaches from the
west.

By Thursday afternoon, a broad surface low will become situated
just south of the Hudson Bay with the axis of a broad
mid/upper- level trough extending through the Great Lakes. As
the surface low deepens and tracks north and east further into
central Quebec, the aforementioned trough will dig south and
east further into the Great Lakes and Ohio Valley regions,
gradually taking on a positive tilt. Mid/upper-level winds will
begin to increase across eastern New York and western New
England as a result of a developing jet max embedded within the
leading edge of the trough. At the surface, a northeast to
southwest-extending cold front will remain upstream through
Thursday night, though shower chances will increase out ahead of
it as large scale ascent becomes favorable with increasing PVA
and warm air/moisture advection increases through continuous
southwesterly flow.

Though there continues to be some level of uncertainty in the
timing of the cold fropa due to model disagreement, general
consensus would point towards a slow northwest to southeast
progression throughout the day Friday. Despite Thursday night`s
increased cloud coverage lingering into Friday, medium-range
models and ensemble members indicate areas of moderate
instability (500-1000 J/kg according to the latest GEFS) Friday
afternoon specifically within the Capital Region, Mid- Hudson
Valley and portions of western New England (~45-60% SBCAPE >
1000 J/kg per the latest SREF) courtesy of possible breaks of
sun in these areas during the morning and possibly early
afternoon. With a persistent southwesterly flow regime, moisture
will continue to be on the increase throughout the night
Thursday into Friday with dew points anticipated to increase to
the upper 50s to 60s and PWATs to rise to about 1.5" by Friday
afternoon. Therefore, have included widespread chances for
showers and thunderstorms throughout much of eastern New York
and western New England for Friday.

At this time, it is difficult to determine the anticipated
strength of convection for Friday, but it is worth noting that
the SPC has placed portions of the Mid-Hudson Valley and western
New England in a Slight Risk for severe thunderstorms. Latest
thermal profiles paint the picture of a low shear, moderate CAPE
environment which could be a limiting factor in convection
reaching severe strength. Additionally, the synoptic forcing, at
this time, looks to be somewhat unfavorable with much of the
area remaining largely within the right exit region of the
upper-level jet. Increased vertical ascent forced through
cyclonic vorticity advection within the upper- trough could help
to compensate for this, but too many factors still remain
uncertain to make that conclusion. However, all that said, there
are some signals for periods of moderate to potentially heavy
rain especially where instability is greatest given the
increased moisture and anticipated forcing. Therefore, mentioned
heavy rain with thunderstorms from Albany south and east Friday
afternoon into Friday evening to account for this possibility.

High temperatures Friday look to range from the mid/upper 70s to
low 80s with pockets of low 70s at higher elevations. Showers
and thunderstorms look to gradually taper off after sunset
Friday night given the loss of daytime heating. Dry conditions
will then be reinstated across the region with low temperatures
anticipated to be in the mid/upper 40s to upper 50s.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Upper ridging steadily builds into the region from the west and
amplifies as it builds into our region. A weak upper impulse is
expected to track along or just north of the U.S./Canada border
some time between Sunday night and Monday night. There are
disagreements with the timing of this upper impulse, that would
potentially bring an isolated shower or thunderstorm as a
weakening wind shift boundary drops south.

Once that upper impulse exits, upper ridging will amplify and
potentially dangerous levels of heat may set up in our area. There
is an increasing consensus from sources of guidance/ensembles for
the potential dangerous levels of heat, so trends will be watched
closely. Any wind shift boundary will just become a thermal surface
trough once the hot airmass settles over our region. The upper
ridging should provide enough of a midlevel cap to prevent any
thunderstorm activity outside of an isolated storm perhaps in areas
of terrain.

Highs Saturday in the 70s with near 80 mid Hudson Valley and 60s to
near 70 higher terrain. Highs Sunday in the upper 70s to lower 80s
with lower to mid 70s higher terrain. Highs Monday in the 80s to
near 90 and around 80 to lower 80s higher terrain. Highs Tuesday in
the lower to mid 90s with mid to upper 80s higher terrain. The 90+
temperatures could continue beyond Tuesday.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
Upper disturbance producing a ceiling at around 5-6 kft across much
of the region. A brief period of MVFR ceilings is expected between
12-14Z at KGFL and KALB. There are a few small breaks in the clouds
but based on satellite imagery the holes in cloud coverage are
trending more to filling in rather than expanding. Clouds are
expected to break up this afternoon and evening. VFR ceilings and
visibilities through today and tonight.

Variable winds at less than 5 kt to near calm through mid-morning.
Then south to west winds at less than 10 kt late this morning
through afternoon, trending to calm this evening and tonight.

Outlook...

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

&&

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

&&

$$

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