266
FXUS61 KALY 111346
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
946 AM EDT Sat May 11 2024

.SYNOPSIS...
An upper level low will approach from the west today with
isolated to scattered rain showers developing, especially for
areas west of the Hudson River. These showers will then spread
eastward tonight into Sunday. Cool conditions are expected on
Mother`s Day but warmer weather returns to start out the new
work week along with continued rain chances.

&&

.NEAR TERM /THROUGH TONIGHT/...
.UPDATE...As of 945 AM EDT, an upper-level trough continues to
depart the region to the east early this morning as some weak
ridging builds in for the midday hours. This will be followed by
a stronger negatively tilted upper-level low approaching from
the Great Lakes. Any low stratus and fog has lifted across the
region and has resulted in variable cloud cover ranging from
mostly sunny across portions of the mid-Hudson Valley into
northwestern CT to mostly cloudy from around the Capital
District and points north and west including southern Vermont. A
trend toward a mostly cloudy sky is expected for most areas
through the afternoon.

While most areas are starting out dry, some very weak
instability-driven showers are ongoing across portions of the
western Mohawk Valley and Adirondacks. Some slight decrease in
these showers are possible over the next few hours, but then
activity will increase in coverage this afternoon as the next
upper-level low approaches. Weak instability will likely
develop with SBCAPE values between 100-300 J/kg. This, combined
with forcing from the approaching upper low will result in
isolated to scattered rain showers. Have updated the wx grids to
coverage wording as we do expect showers to develop but not
everywhere may see one. The 12z KALY sounding shows a
pronounced inversion around 600 hPa which is likely the maximum
level/height that these showers can grow in the vertical. With
the expected shallow nature of these showers, thunder is
unlikely.

Highs today will run a few degrees below normal ranging from the
50s across the higher elevations to the lower to mid-60s in the
valleys.

Scattered to numerous rain showers will spread eastward through
tonight as the core of the upper low moves overhead by Sunday
morning. Overnight temperatures again fall to overnight lows in
the upper 30s in high terrain and low to mid 40s elsewhere.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
The upper low will pass overhead and continue eastward over New
England on Mother`s Day. Resulting showers may linger into the
morning on the western flank of the circulation, however
coverage will decrease into the afternoon as the feature
continues eastward over the Gulf of Maine. A brief dry break
will then last through Sunday night as heights rise aloft behind
the upper low. Temperatures remain cool beneath the upper low,
with afternoon highs only reaching the upper 40s to low 50s in
high terrain and mid to upper 50s at lower elevations, and
overnight lows dipping into the mid 30s to mid 40s across the
region.

As upper ridging flattens over the region, a warm front will
approach from the west on Monday, bringing increasing chances
for rain showers into the afternoon. Temperatures will moderate
as mid-level flow shifts out of the southwest behind the
boundary, with temperatures reaching afternoon highs in the mid
to upper 50s in high terrain and low to mid 60s at lower
elevations. Increased cloud cover overnight will aid in keeping
temperatures mild, as overnight lows only fall to the upper 40s
to mid 50s across the region.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
We start the long term off with a weak surface low tracking through
Quebec near the Hudson Bay and its attendant cold front approaches
the Northeast. Southerly flow ahead of the boundary ushers in a
warmer air mass allowing temperatures on Tuesday to warm towards 70
which is right around the climatological norm. Meanwhile, in the
Ohio Valley we will be monitoring an initially open trough. As the
trough shifts eastward, southwesterly winds along and ahead of our
cold front will strengthen, enhancing the moisture
advection/convergence along the boundary. In fact, PWATs rise above
1" making it feel rather humid on Tuesday. The increased moisture
convergence plus height falls ahead of the wave will likely result
in areas of showers along and ahead of the cold front which is why
we maintained widespread likely POPs for Tuesday into Tuesday night.
The increased humidity will also keep a slight chance for
thunderstorms. Guidance suggests an inverted trough develops along
the boundary given this set-up and with enhanced PWATs, periods of
steady rain look possible.

Recent trends indicate that our initially open wave in the Ohio
Valley may close off which would prolong precipitation into
Wednesday. There are still discrepancies among the guidance if this
wave remains open or closes off/slows down but with the trough in
the left exit region of a jet streak, we decided to account for
recent pessimistic trends and linger chance POPs through the day
Wednesday. In fact, the trough may even linger into Thursday if it
closes off based on some latest trends but we maintained a dry
forecast until there is more of a consensus.

Once the trough/closed low finally exits, there should be a brief
dry respite as high pressure builds in behind it with a warm air
mass continuing overhead. This should support near to even warmer
than normal temperatures once high pressure takes control. However,
the dry break is short-lived as our next boundary looks to arrive
for the weekend.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
IFR cigs and vis at POU will diminish by 13 UTC with VFR conditions
at all other sites. Latest radar mosaic shows a few showers still
around ALB so we maintained VCSH through this morning. Clouds this
morning should break for some sun this morning (especially at POU)
before clouds return midday into the afternoon once we reach our
convective temperatures. This should result in ceilings redeveloping
at 17 to 18 UTC at 5-7kft. A few showers may be in the vicinity of
GFL and ALB through the day but not enough confidence of a shower
passing directly over the terminal to include in the latest TAF.

Showers become more numerous by or shortly after 00 UTC as an upper
level disturbance from the Midwest slides from west to east.
Ceilings lower by or shortly after 00 UTC and result in MVFR levels.
GFL will likely be the first to drop followed by ALB, PSF and POU
shortly after 06 UTC as showers become more widespread.

Southeasterly winds near or under 5kts this morning become a bit
stronger by or shortly after 21 UTC as the sfc pressure gradient
tightens resulting in sustained winds ranging 6 - 9kts with gusts up
to 12kts or so. These winds continue through the end of the TAF
cycle.

Outlook...

Sunday Night: No Operational Impact. NO SIG WX.
Monday: Moderate Operational Impact. Chance of SHRA.
Monday Night: Moderate Operational Impact. Chance of SHRA.
Tuesday: High Operational Impact. Likely SHRA...TSRA.
Tuesday Night: High Operational Impact. Likely SHRA...TSRA.
Wednesday: Moderate Operational Impact. Chance of SHRA...TSRA.
Wednesday Night: Low Operational Impact. Slight Chance of SHRA.

&&

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

&&

$$

SYNOPSIS...Picard/Rathbun
NEAR TERM...Picard/Rathbun
SHORT TERM...Picard
LONG TERM...Speciale
AVIATION...Speciale