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089
FXUS61 KALY 251738
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
138 PM EDT Sat May 25 2024

.SYNOPSIS...
High pressure will bring dry and seasonable weather through
much of today. A few showers and thunderstorms may move in from
the west this evening. Dry conditions to start Sunday, with
widely scattered showers and thunderstorms developing during the
afternoon mainly south of Albany. A stronger low pressure
system is expected to bring a widespread rainfall and breezy
conditions Monday into Monday night, with occasional showers
lingering into midweek.

&&

.NEAR TERM /THROUGH SUNDAY/...
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.UPDATE...As of 138 PM EDT...Skies continue to be primarily
clear this afternoon, though visible satellite shows a larger
band of high clouds encroaching upon the region from the west
ahead of developing convection in western NY. Temperatures are
currently in the low to upper 70s with dewpoints generally in
the upper 40s to low 50s, making for quite comfortable
conditions. We will continue to remain dry throughout much of
the afternoon despite upstream convection courtesy of shortwave
ridging dominant aloft. However, as a weak disturbance
approaches late this afternoon and evening, we could have some
scattered showers and possibly a few rumbles of thunder mainly
north and west of Albany. See previous discussion for additional
details.

.PREV DISCUSSION[0343]...Surface high pressure and short wave
ridging aloft will be over the region this morning into the
afternoon, providing dry conditions. The pressure gradient and
winds aloft will be weaker than Friday, so winds will be much
lighter today. High level clouds will gradually increase, but
will just filter the sunshine until later in the afternoon when
they become thicker. Highs expected to reach the lower 80s in
most lower elevation areas with 70s in the higher terrain. While
dewpoints will rise into the 50s during the afternoon, humidity
levels will still feel comfortable.

Late in the day, heights aloft will start to flatten out as a
shearing disturbance approaches from the west. Isolated to
scattered showers and a few thunderstorms approaching from the
west may hold together as they cross our area during the
evening. Surface based instability will be waning though and
limited to begin with (SBCAPE < 500 J/Kg). So storms are not
expected to be severe. Activity should generally wane by around
midnight, although a few rogue leftover showers may still occur
overnight. Lows will be milder than the past few nights with mid
50s to lower 60s.

Upper level heights look to rise on Sunday, with flat/short
wave ridging developing. The morning should be dry with sunshine
to start the day. Guidance depicting a diffuse surface boundary
stalled across the southern part of the area, which will be the
focus for widely scattered showers/T-storms during the
afternoon once diurnal heating can build enough instability.
Around 500-1500 J/Kg SBCAPE forecast from around Albany
southward, although deep layer shear looks modest ~20-25 kt. So
there could be a few stronger storms, but the overall severe
threat is low, especially given weak/subtle forcing. It will be
a warm day with highs ranging from the mid/upper 70s in the
mountains to mid 80s in valleys. It will turn slightly humid as
dewpoints approach or slightly exceed 60F south of Albany.
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&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
Any leftover convection should diminish Sunday evening once
daytime heating is lost. Also ridging aloft will strengthen
overnight as the pattern amplifies. A deepening upper level
trough will start to approach from the Great Lakes, but forcing
should remain just west of our area through the night so it
should be mainly dry with increasing clouds and low chance of a
few showers developing by daybreak. Lows will be mild again in
the mid 50s to lower 60s.

On Monday, a anomalously deep cyclone (MSLP anomalies of -2 to
-3 STDEV) is forecast to track NE from the upper Great Lakes
Mon morning to near the Ontario/Quebec Mon evening. Southerly
winds will strengthen across our area ahead of the system`s
surface front that will push east into western NY/PA through
Mon. It will turn breezy, with southerly winds gusting near 30
mph at times. Chances for rainfall will increase through the day
as better forcing arrives late in the afternoon into evening.
Based on the latest guidance we are not expecting to get into a
true warm late Mon into Mon night with more of an occluded front
passing through Mon night. So much of the rainfall should be
more stratiform with occasional embedded convective elements
with some instability aloft. The severe threat is low with
little to no surfaced-based instability. Highs should be
relatively cooler, ranging from mid 60s in the higher terrain to
mid 70s in lower elevations.

There is the threat of some heavier rainfall as PWAT anomalies
increase to around +1 to +3 STDEV. ECMWF ensemble probs for > 2"
rain are < 10% for much of the area, but 30-50% in favored
southerly upslope areas of the SE Catskills. Generally
1.00-1.50" QPF forecast with up to 2" in the S. Adirondacks and
SE Catskills. However, locally higher amounts are possible if
any persistent convective rainfall develops. There continues to
be a Marginal Risk (level 1 of 4) of Excessive Rainfall from WPC
for most of the area, with a small area of Slight Risk (level 2
of 4) in the SE Catskills. The front is expected to push
through towards early Tue morning, so low temperatures will be
mild with mid 50s to mid 60s.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Although our area will be behind the departing cold front on
Tuesday, the upper level trough axis will still be west of the
area on Tuesday. Temps aloft are still fairly warm, so it will
be another seasonably warm day on Tuesday with highs well into
the 70s to near 80. There should be enough clearing for a partly
sunny sky for most areas, especially by afternoon. However,
some additional showers are still possible, mainly for western
and northern areas, as the cyclonic flow around the approaching
upper level trough allows for some showers.

More widespread showers are expected by Wednesday, with the
upper level trough axis centered over the area. The best chance
will be for northern and western parts of the area. In addition
to the showers, skies will be fairly cloudy and temps will be a
little cooler, with highs in the 60s and 70s.

Will continue to mention low POPs even into Thursday in case
the timing changes, as some models do show some timing
differences regarding the upper level trough. Otherwise, there
should be some clearing behind the departing trough, but with
temps aloft still a little cool, highs will likely be on the
cooler side for Thursday, with only 60s across the entire area.

By Friday, mainly dry weather is expected for the entire area
with temps continuing to moderate closer to normal along with a
partly sunny sky. High pressure will be building in from the
west and daytime temps should be back into the lower to middle
70s for valley areas. Through the entire extended period,
overnight lows will be in the 40s and 50s and there shouldn`t be
any risk of frost for the region.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
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SKC to few clouds well above 12000 feet into this evening. A weak
front will bring scattered showers and thunderstorms to the region
between 00Z-06Z, with the best chances at KGFL, KALB and KPOU.
Including PROB30 for IFR visibilities and MVFR ceilings in
thunderstorms in those areas but less coverage around KPSF, so only
including VCSH there.

Once the showers and thunderstorms end, cloudy sky through daybreak
with ceilings trending to MVFR at all TAF sites. Visibilities should
be VFR. After about 14Z, ceilings will lift to around 5000 feet and
broken clouds above 5000 feet should hold through Sunday afternoon
with some intervals of scattered clouds.

Light and variable winds into this evening should become near calm
through the night and then light and variable again Sunday morning
and afternoon.

Outlook...

Sunday Night: Low Operational Impact. Slight Chance of SHRA.
Memorial Day: High Operational Impact. Breezy. Definite SHRA...TSRA.
Monday Night: High Operational Impact. Breezy. Definite SHRA...TSRA.
Tuesday: Moderate Operational Impact. Breezy. Chance of SHRA.
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: Moderate Operational Impact. Chance of SHRA...TSRA.
Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA.
Thursday: Moderate Operational Impact. Chance of SHRA.
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&&

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

&&

$$

SYNOPSIS...JPV
NEAR TERM...Gant/JPV
SHORT TERM...JPV
LONG TERM...Frugis
AVIATION...NAS