Plainfield, Massachusetts Weather Forecast Discussion

682
FXUS61 KBOX 240538
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
138 AM EDT Wed Sep 24 2025
.SYNOPSIS...
Warm and humid conditions with scattered showers and a few
thunderstorms lingering tonight as a front moves into our
region. Much cooler Wednesday with the risk of showers
continuing. Another period of widespread showers and a few
thunderstorms Thursday into Thursday night as another front
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 TODAY/...
Key Messages...
* Warm and humid today with scattered showers and t-storms
  across the interior.
Latest SPC mesoanalysis showed generally less than 500 J/kg of
CAPE across southern New England. Becoming less concerned about
thunderstorms tonight, except perhaps across portions of CT
tonight. Slowed the timing for showers based on observed radar
trends. The latest HRRR and RAP looked to be too aggressive
with rainfall, but did like the timing provided by a time-lagged
ensemble of several HRRR runs this evening. This keeps most of
southern New England dry until just before midnight. Lingering
showers the rest of the overnight, especially towards the south
coast.
Previous Discussion...
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 /TONIGHT THROUGH 6 PM THURSDAY/...
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 NIGHT THROUGH TUESDAY/...
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 /06Z WEDNESDAY THROUGH SUNDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
06z TAF Update...Moderate confidence.
Cigs lowering to MVFR-IFR through 12z. Mostly IFR conditions
today through Thu with areas of LIFR at times. Showers and
embedded t-storms moving through SNE 06-09z, then scattered
showers today. More widespread showers and embedded t-storms
developing from west to east late tonight through Thu. NE wind
5-15 kt today, light E tonight then becoming S 10-15 kt Thu.
KBOS Terminal...Moderate confidence in TAF.
KBDL Terminal...Moderate confidence in TAF.
Outlook /Thursday Night through Sunday/...
Thursday Night: MVFR/IFR conditions possible. SHRA likely,
slight chance TSRA.
Friday: Mainly VFR, with local IFR possible. Chance SHRA.
Friday Night through Sunday: 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 Night through Sunday/...
Thursday: Winds less than 25 kt. Seas locally approaching 5 ft.
Rain showers likely.
Thursday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft. Rain showers, slight chance of thunderstorms.
Friday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Chance of rain showers.
Friday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Chance of rain showers.
Saturday through Sunday: 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 Thursday for ANZ250.
     Small Craft Advisory until 2 PM EDT this afternoon for ANZ254.
     Small Craft Advisory until 9 AM EDT this morning for ANZ255-
     256.
&&
$$
SYNOPSIS...Belk/BW
NEAR TERM...Belk/BW
SHORT TERM...BW
LONG TERM...Belk
AVIATION...Belk/KJC
MARINE...Belk/BW

NWS BOX Office Area Forecast Discussion