Canaan, Connecticut Weather Forecast Discussion

463
FXUS61 KALY 211740
AFDALY
AREA FORECAST DISCUSSION
National Weather Service Albany NY
140 PM EDT Sun Sep 21 2025
.SYNOPSIS...
High pressure will be departing off to the east tonight into
Monday, which will allow for dry and comfortable weather to
continue. An approaching upper level disturbance will bring the
threat for some much needed rain showers to the region for
Monday night into Tuesday. Some additional rainfall is possible
later in the week as well.
&&
.DISCUSSION...
As of 140 PM EDT...Surface high pressure (around 1030 mb) is
located close to the Gulf of Maine and it will be departing off
to the east for tonight. With our area on the western side of
this high pressure area, the low-level southerly flow is now out
of the south, with some gusty winds occurring within the
immediate Hudson Valley thanks to channeling through the
terrain. Visible satellite imagery shows a mostly clear sky,
with some bands of thin high cirrus clouds around. Through
tonight, dry weather will continue with a mostly clear sky. The
light southerly breeze will continue, which should help prevent
widespread fog from developing, although some patchy fog is
still possible, especially across sheltered areas. Temps won`t
be as cool as the last few nights, with lows generally in the
40s. It will stay dry and comfortable into Monday, with a partly
to mostly sunny sky and temperatures reaching the mid 70s in
valley areas.
A weak upper level disturbance will be moving from the Great
Lakes towards the Northeast for Monday night into Tuesday, along
with a surface frontal boundary. Increasing low level moisture
will be occurring ahead of this system thanks to the persistent
southerly flow and dewpoints will be rising through the 50s and
back into the 60s by Tuesday. As a result, some showers are
expected, especially for northern and western areas, which will
be closer to the track of the surface low. QPF looks fairly
light, but most areas will see a quarter to a third of an inch,
which should help due to the recent dry conditions. There is a
25% to 60% chance of 0.50", with the highest values in the
Adirondacks, according to the latest NBM guidance. Although
instability is limited, a rumble of thunder can`t be ruled out,
especially for southern areas, as there be just enough elevated
instability in place, but no strong storms are expected. Temps
will continue to be seasonable, with daytime highs in the mid to
upper 70s on Tuesday.
Behind this system, there will be the potential for some
additional rainfall for the mid to late week. A closed off upper
level low will be moving across the Midwest and will be
approaching the region from the west. There are some different
solutions in the guidance regarding the exact timing of this
feature and how much precip will occur. Will continue to side
close to the blended guidance through the extended period, with
chance POPs each day for Wednesday through Saturday. At this
point, any additional rainfall is much needed, so this could be
beneficial for the region. Temperatures will continue run close
to average or slightly above normal through the mid to late
week period, with valley highs in the 70s and lows in the 50s.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Through 18z Monday...High pressure, though now shifted farther to
the east, remains in place to sustain VFR conditions across all
terminals. Such conditions will continue through much of the 18z
cycle with the exception of brief periods of MVFR to IFR conditions
due to fog development at KGFL and possibly KPSF late tonight. Winds
will remain breezy through this afternoon out of the southeast with
sustained speeds of 5 to 15 kt pairing with gusts up to 20 kt.
Speeds decrease with the loss of daylight this evening, becoming
light to calm overnight and variable tomorrow morning.
Outlook...
Monday Night: Low Operational Impact. NO SIG WX.
Tuesday: Moderate Operational Impact. Likely SHRA...TSRA.
Tuesday Night: Moderate Operational Impact. Chance of SHRA.
Wednesday: Moderate Operational Impact. Chance of SHRA.
Wednesday Night: Moderate Operational Impact. Chance of SHRA.
Thursday: Moderate Operational Impact. Chance of SHRA.
Thursday Night: Moderate Operational Impact. Chance of SHRA.
Friday: Moderate Operational Impact. Chance of SHRA...TSRA.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...Frugis
DISCUSSION...Frugis
AVIATION...Gant

NWS ALY Office Area Forecast Discussion