South Chaplin, Connecticut Weather Forecast Discussion

411
FXUS61 KBOX 231820
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
220 PM EDT Tue Sep 23 2025
.SYNOPSIS...
Warm and humid conditions this afternoon and evening with scattered
showers and a few thunderstorms lingering into tonight as a front
moves into the region. Much cooler Wednesday with risk of showers
continuing, then another period of widespread showers and a few
thunderstorms Thursday into Thursday night as a frontal system moves
into the region. Unsettled weather pattern may linger into Friday,
then gradual improvement this weekend. Above normal temperatures and
increasing humidity return Thursday night into the weekend.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
Key Messages...
* Warm and humid today with scattered afternoon showers and t-storms
  in the interior. These continue through the overnight hours.
Moist SW flow continues to advect a warm and humid airmass into the
region leading to plenty of cloud cover mixing with the sunshine
with showers on our doorstep. These breaks of sun the warm airmass
lead to highs in the upper 70s and low 80s; this with the dewpoints
in the mid to upper 60s will contribute to marginal instability,
with CAPE values on the order of around 500 J/kg. Moisture is
plentiful as well with those dewpoints and PWATs approaching 2
inches and lift will arrive in the form of a weak cold front
dropping south. Severe parameters are not impressive given the weak
lift, moderate CAPE, and bulk shear of 25-30 kts. Even so, there is
enough that an isolated strong storm is possible. Hi-res guidance
continues to point to heavy downpours being possible as well which
could drop 1-2 inches of rain in an hour in a localized area.
Overall, not expecting these showers and t-storms to be very
impactful. Unsettled weather continued to move east through the
region overnight as the front stalls with the threat for passing
downpours continuing into Wednesday.
Wednesday we`ll see the bulk of the overnight showers moving
offshore early as the front sinks south and weak mid level ridging
moves overhead. However, high pressure building over the maritimes
will direct cool, moist NE flow into the region keeping low level
moisture overhead in the form of thick clouds and light rain or
drizzle. Forecast soundings show a nearly saturated atmosphere up to
at least 850 mb in much of SNE. This combined with another
approaching shortwave and moisture plume later Wednesday will mean
continued shower chances all day. Instability should stay south of
the region for the most part, but can`t rule out it clipping part of
CT leading to a rumble of thunder.
Temperature-wise, the cloudcover and northeast flow will mean highs
quite a bit cooler than today, in the mid/upper 60s to 70F. The
warmest location would be parts of the CT valley where downsloping
flow helps them reach the low to mid 70s. Overnight elevated
dewpoints will keep lows mild, in the low to mid 60s.
&&
.SHORT TERM /WEDNESDAY NIGHT/...
Key Messages...
* Showers with low temperatures in the upper 50s and low 60s.
More of the same is expected on Wednesday night with expanding
coverage of showers as the mid level trough gets closer, increasing
lift acting on a 1.5-2" PWAT plume. Low temperatures only dip into
the upper 50s and low 60s.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
Key Messages:
* Another round of more widespread showers and a few thunderstorms
  Thu into Thu night
* Warm weather Fri through this weekend, but unsettled Fri and
  possibly Sat
Still looking unsettled late this week across southern New England.
A mid level trough is nearby, but the heights are not anything
unusual for this time of year. That said, this trough will keep a
surface low pressure nearby as well, taking its time to move from
the Great Lakes into eastern Canada Thursday into Friday. The cold
front associated with this low pressure is still not expected to
pass by our region until sometime Friday afternoon. Even then, this
front could stall just off the coast, keeping at least a risk for
some showers towards the south coast Saturday. High pressure should
finally bring an end to our periodic wet weather, but that is not
likely until sometime on Sunday.
The latest NationalBlend had 80-90% probabilities for at least 1
inch of rainfall int he 72-hours ending 8 PM Friday across most of
southern New England. Slightly lower probabilities of 60-80% across
RI and southeast MA during this same time. There were even modest
probabilities, 40-60% for more than 2 inches of rainfall for an area
from northwest CT into south central MA. Not entirely convinced the
location of the heavier rainfall is correct, but the potential is
there. Given our recent dry conditions, we really could use whatever
rainfall we can get.
Expecting temperatures to be near to slightly above normal for this
portion of the forecast.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
18z TAF update...
This afternoon...High confidence. Moderate for TSRA chances.
Scattered SHRA and isolated TSRA developing after 19z in the
interior. Brief heavy rain and lower cigs/vsbys with any
t-storms. SW wind 10-15 kt with gusts to 20 kt Cape/Islands.
Tonight and Wednesday...Moderate confidence.
Cigs lowering to MVFR-IFR tonight, LIFR possible after
midnight. Scattered showers and a few t-storms tonight. Chance
of showers or patchy drizzle Wed with MVFR/IFR cigs. Winds
shifting to light N tonight north of the south coast, with NE
wind 10-15 kt Wed.
Wednesday Night...High confidence in trends, low confidence in
timing.
IFR cigs in scattered SHRA overnight. Winds around 5kt from the
E and SE.
KBOS Terminal...Moderate confidence in TAF. Low risk for TSRA
late afternoon and evening (22-01Z).
KBDL Terminal...Moderate confidence in TAF. Risk of t-storms
20-00z.
Outlook /Thursday through Saturday/...
Wednesday Night: MVFR/IFR conditions possible. SHRA likely.
Thursday: Mainly MVFR, with areas IFR possible. Breezy. SHRA
likely, slight chance TSRA.
Thursday Night: Mainly MVFR, with areas IFR possible. SHRA
likely, slight chance TSRA.
Friday: Mainly VFR, with local IFR possible. Chance SHRA.
Friday Night: VFR. Chance SHRA.
Saturday: VFR. Slight chance SHRA.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Through Wednesday night...High Confidence.
SCA for outer waters into Wed for marginal seas. Winds expected to
remain below SCA. SW gusts to 20 kt today, then shifting to E-NE 10-
20 kt Wed, diminishing a bit overnight.
Outlook /Thursday through Saturday/...
Wednesday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft. Chance of rain showers.
Thursday: Winds less than 25 kt. Seas locally approaching 5 ft.
Rain showers likely.
Thursday Night through Friday: Winds less than 25 kt. Seas
locally approaching 5 ft. Rain showers likely, slight chance of
thunderstorms.
Friday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Chance of rain showers.
Saturday: Winds less than 25 kt. Chance of rain showers.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 2 AM EDT Wednesday for ANZ235-237.
     Small Craft Advisory until 8 PM EDT Wednesday for ANZ250.
     Small Craft Advisory until 2 PM EDT Wednesday for ANZ254>256.
&&
$$
SYNOPSIS...Belk/BW
NEAR TERM...BW
SHORT TERM...BW
LONG TERM...Belk
AVIATION...Belk/BW
MARINE...Belk/BW

NWS BOX Office Area Forecast Discussion