439
FXUS61 KALY 120856
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
456 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/...
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. 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 /08Z WEDNESDAY THROUGH SUNDAY/...
Upper disturbance producing a ceiling at around 5000-6000 feet
across much of the region. There are a few breaks in the clouds
but small and based on satellite imagery the holes in the
clouds are trending more to filling in rather than expanding.
The cloud cover should limit the potential for fog as the
surface will likely not get saturated but some of the holes
around KGFL could support some intervals of fog between about
09Z-12Z. VFR ceilings and visibilities after 12Z and through the
rest of the day and evening.

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 and evening.

Outlook...

Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: No Operational Impact. NO SIG WX.
Thursday Night: Low Operational Impact. Slight Chance of SHRA...TSRA.
Friday: Moderate Operational Impact. Chance of SHRA...TSRA.
Friday Night to Sunday: 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