Severe Thunderstorm Warning 16, NWS Boston/Norton, MA

330 
WWUS51 KBOX 122327
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
727 PM EDT Fri Jun 12 2026

CTC003-122345-
/O.CON.KBOX.SV.W.0016.000000T0000Z-260612T2345Z/
Hartford CT-
727 PM EDT Fri Jun 12 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR SOUTHWESTERN HARTFORD COUNTY...

At 726 PM EDT, a severe thunderstorm was located over Southington,
moving southeast at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to trees and power lines.

Locations impacted include...
New Britain, Bristol, Southington, Newington, Farmington, Berlin,
Rocky Hill, and Plainville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4163 7269 4163 7271 4160 7272 4157 7280
      4155 7282 4157 7283 4157 7285 4155 7285
      4156 7288 4156 7294 4163 7293 4164 7294
      4164 7299 4168 7293 4170 7278
TIME...MOT...LOC 2326Z 306DEG 30KT 4164 7288 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$
Manning

216 
WWUS51 KBOX 122333
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
733 PM EDT Fri Jun 12 2026

CTC003-122343-
/O.CAN.KBOX.SV.W.0016.000000T0000Z-260612T2345Z/
Hartford CT-
733 PM EDT Fri Jun 12 2026

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN HARTFORD COUNTY
IS CANCELLED...

The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However gusty winds are
still possible with this thunderstorm.

LAT...LON 4163 7269 4163 7271 4160 7272 4157 7280
      4155 7282 4157 7283 4157 7285 4155 7285
      4156 7288 4156 7294 4163 7293 4164 7294
      4164 7299 4168 7293 4170 7278
TIME...MOT...LOC 2329Z 308DEG 34KT 4160 7281 

$$
Manning

Area Forecast Discussion
National Weather Service Boston/Norton MA
348 PM EDT Fri Jun 12 2026

.WHAT HAS CHANGED...
The slight risk (level 2 of 5) of severe weather today remains in
effect for far western CT and MA. The chance of severe weather also
remains low, but not zero, for eastern MA/RI.

&&

.KEY MESSAGES...

- Isolated to scattered storms possible through this evening. A
  few may be strong to severe.

- Above normal temperatures continue this weekend, though
  humidity levels drop to more comfortable levels.

&&

.DISCUSSION...
KEY MESSAGE 1...Isolated to scattered storms possible through
this evening. A few may be strong to severe.

Under a moist and unstable airmass, a mid-level shortwave trough
moves over Quebec helping trigger showers and thunderstorms this
afternoon and evening. No major changes from the previous forecast.
Modest shear paired with the daytime heating helping build
instability (MLCAPE 1000-2000 J/kg). Recent runs of high-res
guidance have shown a range of isolated to scattered storms.
Some of the CAMs continue to show a few storms firing off a sea
breeze boundary in east southern New England. There is also a
general consensus across guidance for storms to develop in
western MA/CT ahead of the cold front early this evening, moving
eastward. Can't rule out a strong to severe storm or two with
the greater risk in west and central portions of southern New
England. Gusty, locally damaging winds and lightning are the
main hazards. Brief downpours are also possible within any
storms. Any remaining showers or storms push offshore by
midnight.

KEY MESSAGE 2...Above normal temperatures continue this weekend,
though humidity levels drop to more comfortable levels.

An anomalously warm airmass remains over the region this weekend
with ridging aloft. This will support above normals highs well into
the 80s with some low 90s. Despite the similar temperature readings
from the last few days, it won't feel as sweltering as it has been
Saturday. Dewpoints stay in the mid to upper 50s which will take out
the humidity factor and provide some marginal relief. With ridging
aloft, conditions stay dry for Saturday and a good portion of
Sunday. Next chance for showers/storms returns later Sunday with
moisture/humidity increasing later in the day. More on that in the
next key message below.

KEY MESSAGE 3...Showers and thunderstorms Sunday evening/overnight,
but the risk for severe weather is low.

After another very warm to hot Sunday, a cold front will be
progressing into and through Southern New England Sunday night,
which will increase the risk for showers and thunderstorms. Midlevel
flow aloft increases and supports increasing deep-layer shear
magnitudes of around 35 to 40 kt. However it still looks like
instability looks on the low side, both due to the time of day post-
sundown and lower dewpoints, which is a significant limiting factor
to how strong any storms may get. Both CSU and NSSL machine-learning
progs indicate low (< 10%) probs of severe weather for Sunday night.
Still expect some thunderstorms to develop/move eastward into the
night but the risk they produce severe weather seems low. Even how
much rainfall we get from these storms is uncertain, despite
elevated PWATs in the 1.5-1.8" range, as some of the global models
(GFS/Canadian) simulate a convectively-driven subsynoptic low over
the mid-Atlantic states which moves well offshore of Southern New
England into the overnight. Were this to develop, it could greatly
reduce how much rainfall we do get. Others, such as the ECMWF/its
ensemble mean, generate about a quarter to half inch of rain
areawide. Increased PoPs into the Categorical range between the
02- 10z timeframe from west to east before drying out as cold
front moves through.

KEY MESSAGE 4...Return to more seasonable temperatures and lower
humidity levels for the early to middle part of next week,
then turning more active again into Thursday.

A cooler and much drier airmass then works into Southern New England
Monday into Tuesday. Latest guidance shows 850 mb temps now dropping
to around +8 to +10C, some 5 degrees C lower than today. Highs more
into the 70s to low 80s with dewpoints plummeting into the mid
40s to mid 50s, so also substantially less humid compared to
prior days with full sunshine. Early next week looks like a
great stretch of summer weather; temperatures do start to warm
up again as we move into Wednesday but are still seasonable in
the low to mid 80s with still tolerable humidity levels.

More active weather looks to develop around Thursday or Thursday
night, as a stronger disturbance aloft moves in and sweeps a cold
front through Southern New England. This could bring a better shot
at showers/storms, although it's still too early for specifics at
this timeframe.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
Forecaster Confidence Levels...

Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

18Z TAF Update:

Today: Moderate confidence.

VFR. Light onshore winds for north coastal terminals, with
light W winds away from the coastal TAFs. A few rounds of TSRA
could develop, first in the 18-00Z time period over eastern MA
and RI terminals along the seabreeze boundary, but confidence in
coverage and placement is low. Then again a broken line of
storms is possible in the 22z-04z period, diminishing as it
moves east.

Tonight...High confidence.

SHRA/TSRA exiting by 04z. VFR except near the Cape/Islands
where MVFR visbys under BR may creep in off the waters. NW winds
5-10 kts. Winds shift to the NW 00-04Z.

Saturday....High confidence.

VFR. NW winds around 8-12 kts.

KBOS Terminal...Moderate confidence in TAF. VFR. Could see a
few TS develop 19-00z along the seabreeze boundary. Given the
low confidence in placement, messaged as a VCTS given the
boundary will be nearby. Low chance for another round of storms
from western southern new england to reach the terminal. By the
time it get east to the terminal, they are more likely to be
SHRA.

KBDL Terminal...Moderate Confidence in TAF. VFR. Light W winds.
Becoming NW after 00Z. Isolated thunderstorms possible 22-01Z.

Outlook /Saturday Night through Wednesday/...

Sunday: VFR. Breezy.

Sunday Night: Mainly VFR, with local MVFR possible. Breezy.
SHRA, isolated TSRA.

Monday: VFR. Breezy.

Monday Night: VFR.

Tuesday: VFR. Breezy.

Tuesday Night: VFR.

Wednesday: VFR. Slight chance SHRA.

&&

.MARINE...
Forecaster Confidence Levels...

Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

Through Saturday Night...High confidence.

Seas generally 1-3 ft, except 3-4 ft across the far outer waters
through Saturday morning. Isolated to scattered showers perhaps
an isolated storm over the waters this evening. Otherwise, winds
remain below SCA levels.

Outlook /Saturday Night through Wednesday/...

Sunday: Winds less than 25 kt.

Sunday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of seas approaching 5 ft. Rain
showers, slight chance of thunderstorms.

Monday: Winds less than 25 kt. Slight chance of rain showers.

Monday Night: Winds less than 25 kt. Areas of seas approaching
5 ft.

Tuesday: Winds less than 25 kt. Seas locally approaching 5 ft.

Tuesday Night: Winds less than 25 kt.

Wednesday: Winds less than 25 kt. Areas of seas approaching
5 ft.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory until 8 PM EDT this evening for CTZ002>004.
MA...Heat Advisory until 8 PM EDT this evening for MAZ002>006-
     008>014-017-018-026.
     Air Quality Alert until 11 PM EDT this evening for MAZ017>024.
RI...Heat Advisory until 8 PM EDT this evening for RIZ001>004.
     Air Quality Alert until 11 PM EDT this evening for RIZ001>008.
MARINE...None.

&&

DISCUSSION...Loconto/Mensch
AVIATION...Mensch
MARINE...Loconto/Mensch