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644
FXUS61 KALY 182320
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
720 PM EDT Wed Sep 18 2024

.SYNOPSIS...
Surface high pressure continues through tonight with increasing
clouds as a weather system moves along the Atlantic Coast. This
weather system could bring chances of rain showers into
Thursday. Friday could see some lingering showers in the Mid-
Hudson Valley and Litchfield Hills region, otherwise dry
conditions are in store into this weekend through early next
week with seasonable temperatures.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
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.UPDATE...As of 0720 PM EDT, enhanced coverage of high clouds
continues, with more solid coverage to the north of I-90 per
latest IR imagery. Thinner cloud coverage may lift northward
through tonight ahead of a surface low developing south of New
England, with cloud breaks potentially supporting patchy valley
fog, most likely to the north and west of Albany. Increased
cloud coverage will return from the south by morning as the
coastal low deepens. Temperatures currently in the 60s to low
70s will trend downward to morning lows in the 50s across much
of the region. Forecast therefore remains on track; see previous
discussion below...

.PREV DISCUSSION [0355 PM EDT]...Zone of thick high clouds in
much of eastern NY and western New England but satellite picture
trends show the high clouds shifting north and some more
scattered lower clouds just south of the eastern Catskills and
mid Hudson Valley holding nearly stationary.

Upper ridging north and west of the developing coastal system
well south of Long Island may enhance some subsidence and allow
for the high clouds to thin through the evening and night with
some possible river and wetland fog again, and some scattered
low clouds across the region. Light to calm winds will help for
some radiational cooling where the high clouds thin and where
there is clearing.

Low level dew points have risen as boundary layer flow had
become more east to southeast. So, once temperatures approach
dew points later tonight, again, patchy fog with low
temperatures a little warmer than past nights. Lows in the mid
to upper 50s with around 50 to lower 50s northern areas.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
System offshore continues to organize and there are some
differences in sources of guidance/ensembles as to how far north
and west the rain shield gets. Intervals of clouds and sun
Thursday as any northern edge of any precipitation shield would
hold off until Friday, with the best chances on Friday in the
mid Hudson Valley, Litchfield Hills and Berkshires. A northern
stream upper impulse dropping out of far eastern Canada is
expected to push slightly cooler air from the north and east
into our region and that low level forcing could interact with
the coastal storm, supporting the scattered showers in our
region. An isolated shower cannot be ruled out from the
Schoharie Valley to Capital Region to southern Vermont.

So, with the intervals of clouds and sun Thursday, and more
clouds with more clouds south and east of the Capital Region,
temperatures will be a little cooler than recent days, but highs
Thursday will be in the mid 70s to lower 80s. On Friday, the
better chance of showers with the weak backdoor front and
northern precipitation shield from the coastal storm, highs in
the mid to upper 70s with lower 70s higher terrain.

Lingering clouds and isolated showers east of the Hudson River
Saturday with less cloud cover west of the Hudson River as the
coastal system begins to slowly exit and the weak backdoor
front washes out. Highs Saturday around 70 to mid 70s. Slowly
improving sky Saturday night, especially in western areas with
lows in the 50s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Flat upper ridging builds in from the west, as overall upper
heights fall with an approaching developing upper impulse
approaches from Canada and the Great Lakes, dry weather Sunday
through Tuesday with possible showers by later Tuesday through
Wednesday with the approach of a cold front.

There are lots of differences in sources of guidance as to the
strength of the upper energy, the timing and any colder air as
the system exits. Temperatures will at least be normal, with a
chance for a bit above normal if the upper ridging weakens the
upper energy and there is less cool air behind the system. But
for now, the best chances for showers look to be later Tuesday
and Wednesday but confidence is low.

Highs Sunday through Wednesday in the upper 60s to lower 70s
with cooler in higher elevations.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
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Through 00Z Friday...VFR conditions expected to prevail
throughout the TAF period at all terminals, aside from patchy
fog/mist overnight. Bkn-ovc high ci at 20-25 kft will likely
continue through the period as a surface low develops south of
New England. Periods of reduced ci coverage are possible
overnight if upper ridging to the north and west results in
subsidence sufficient to encourage clearing. This potential
clearing would support an elevated risk of radiation fog
formation, most likely within sheltered valleys to the north and
west of Albany, including at GFL where patchy fog may develop
as early as 04Z Thu with increasing chances toward dawn. Other
terminals will see more enhanced high cloud cover and therefore
lower chances for fog. Intermittent IFR/LIFR vsbys are possible
within fog banks, before conditions return to VFR when fog
dissipates by 12-13Z Thu. As the system south of New England
deepens, isolated rain showers are possible at POU after 18Z
Thu, but no impacts to flying conditions are expected.

Calm or light and variable winds will continue into tonight,
before increasing out of the north to northeast at 5-10 kt by
12-15Z Thu.

Outlook...

Thursday Night: No Operational Impact. NO SIG WX.
Friday: Low Operational Impact. Isolated SHRA.
Friday Night: Low Operational Impact. Isolated SHRA.
Saturday: Low Operational Impact. NO SIG WX.
Saturday Night: Low Operational Impact. Isolated SHRA.
Sunday: No Operational Impact. NO SIG WX.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.
-- End Changed Discussion --

&&

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

&&

$$

SYNOPSIS...NAS
NEAR TERM...NAS/Picard
SHORT TERM...NAS
LONG TERM...NAS
AVIATION...Picard