Cornwall Bridge, Connecticut Weather Forecast Discussion

005
FXUS61 KALY 031018
AFDALY
AREA FORECAST DISCUSSION
National Weather Service Albany NY
618 AM EDT Fri Oct 3 2025
.SYNOPSIS...
Warming trend ensues today with increasing confidence for above
normal temperatures through early next week. While we remain dry
through at least Monday, confidence is also increasing for our
next widespread rain event next Tuesday into Wednesday before we
turn cooler for the end of next week.
&&
.SHORT TERM /THROUGH SUNDAY/...
Key Messages:
- High confidence in above normal temperatures through early
  next week.
Discussion:
Chilly start again today with patchy frost in the higher terrain
and hill towns as overnight temperatures fell into the 30s and
40s. Our ~1030hPa high settles off the coast of NJ today with
upper level ridging flattening out overhead as a weak disturbance
tracks through southern Canada. Large scale subsidence will
maintain sunny skies mixed with some cirrus and westerly flow
aloft will advect a milder air mass into the Northeast. While
850hPa isotherms reach +11C to +12C, forecast soundings suggest
shallower boundary layer mixing which likely keep temperatures
in check. Probabilistic guidance shows high temperature spread
between the 25th and 75th percentile limited to the low to mid
70s for valley areas today with upper 60s for the higher
terrain areas. Heading into tonight, ridging aloft gradually
amplifies supporting clear skies and light winds resulting in
favorable radiational cooling. With dew points a bit elevated,
expecting more fog formation. Overnight lows should not be quite
as cool as previous nights thus preventing frost but falling
into the 40s.
Saturday and Sunday will certainly feel more like early
September than early October as ridging over the Great Lakes and
Northeast restrengthens and westerly flow aloft advects 850hPa
isotherms between +12C and +14C. While skies remain sunny,
boundary layer mixing is a bit shallow on forecast soundings on
Saturday but deepens slightly for Sunday as the sfc high
gradually slides to our east. Regardless, there is medium to
high confidence that temperatures will reach 10 to 15 degrees
above normal both days given the low spread in the
probabilistic guidance with the 25th and 75th percentile values
ranging from the mid-70s to near 80, outside of the southern
Adirondacks and southern Greens. Overnight lows trend milder as
well but with a rather dry air mass, expecting a large diurnal
swing as overnight temperatures fall into the 40s and 50s. Will
need to monitor fog formation given favorable radiational
cooling.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Key Messages:
- There is a 50-70% chance for greater than one half inch of
  rain across eastern NY and western New England next Tuesday
  into Wednesday.
Discussion:
While the dry and unseasonably warm trend continues into
Monday, our attention then turns to a shortwave trough and
associated sfc cold front progressing form southern Canada into
the Northeast. Guidance has trended earlier with the start time
of the rain ahead of the sfc boundary with most ensembles now
suggesting rain spreads into areas north and west of Albany
Tuesday evening before rain advances further east overnight.
There remains uncertainty regarding the intensity of the
shortwave trough tracking through Canada which will provide the
necessary forcing for ascent to enhance the precipitation
shield along the incoming boundary. Ensemble clusters suggest
two types of scenarios. If the trough become neutrally to even
slightly negatively tilted by Tuesday night, the CVA ahead of it
should be strong enough to support a widespread soaking rain
with 24-hr rainfall probabilities through 00 UTC Wed for near
or above 0.50" ranging 50-70%. On the other hand, should the
trough be weaker, limited CVA along the boundary will keep
rainfall amounts lower with 24-hr rainfall probabilities for at
or greater than 0.50" near or under 30%.
The latest guidance suggests the quicker arrival of the front
would allow most rain to finish during the day Wed with a sharp
wind shift along the front and strong high pressure building
south/eastward out of the Canada supporting notable cold air
advection. In addition, a tightening pressure gradient would
also support breezy winds. Temperatures therefore trend much
cooler and more fall-like for the end of the week.
&&
.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
Thru 12Z Sat...Mainly VFR conditions the next 24 hours for
KGFL/KALB/KPOU/KPSF with IFR/LIFR mist/fog at KGFL this morning
due to radiational cooling prior to 13Z/Fri. VFR conditions are
expected for all the TAF sites for the rest of the morning
through the afternoon with a few-sct cirrus with high pressure
near the region. The winds will be light to calm this morning
and then increase from the south to southwest at 4-7 KT. The
winds will become light and variable at 4 KT or less after
23Z/Fri. Some IFR/LIFR radiational mist/fog may form at
KGFL/KPSF between 04Z-06Z/SAT.
Outlook...
Sat Night to Mon Night: No Operational Impact. NO SIG WX.
Tue: Low Operational Impact. Slight Chance of SHRA.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...31
SHORT TERM...31
LONG TERM...31
AVIATION...15

NWS ALY Office Area Forecast Discussion