Severe Thunderstorm Warning 4, NWS Boston/Norton, MA

189 
WWUS51 KBOX 160420
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
1220 AM EDT Thu Apr 16 2026

CTC003-013-MAC013-015-160430-
/O.CON.KBOX.SV.W.0004.000000T0000Z-260416T0430Z/
Tolland CT-Hartford CT-Hampshire MA-Hampden MA-
1220 AM EDT Thu Apr 16 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1230 AM EDT
FOR NORTHWESTERN TOLLAND...HARTFORD...SOUTHEASTERN HAMPSHIRE AND
SOUTHERN HAMPDEN COUNTIES...

At 1220 AM EDT, severe thunderstorms were located along a line
extending from near Southampton to Windsor to near Farmington, moving
east at 45 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Springfield, Hartford, New Britain, West Hartford, Bristol,
Manchester, Chicopee, East Hartford, Enfield, Westfield, Holyoke,
Glastonbury, Newington, Vernon, Windsor, Agawam, West Springfield,
Wethersfield, South Windsor, and Farmington.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4214 7293 4216 7294 4217 7294 4217 7282
      4222 7231 4188 7233 4168 7243 4170 7299
      4180 7301 4181 7294 4185 7280 4188 7281
      4196 7280 4202 7280 4207 7284 4211 7289
      4213 7292
TIME...MOT...LOC 0420Z 269DEG 37KT 4219 7272 4189 7266 4175 7280 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Loconto

839 
WWUS51 KBOX 160429
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
1229 AM EDT Thu Apr 16 2026

CTC003-013-MAC013-015-160439-
/O.EXP.KBOX.SV.W.0004.000000T0000Z-260416T0430Z/
Tolland CT-Hartford CT-Hampshire MA-Hampden MA-
1229 AM EDT Thu Apr 16 2026

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN TOLLAND...
HARTFORD...SOUTHEASTERN HAMPSHIRE AND SOUTHERN HAMPDEN COUNTIES WILL
EXPIRE AT 1230 AM EDT...

The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with these thunderstorms.

LAT...LON 4214 7293 4216 7294 4217 7294 4217 7282
      4222 7231 4188 7233 4168 7243 4170 7299
      4180 7301 4181 7294 4185 7280 4188 7281
      4196 7280 4202 7280 4207 7284 4211 7289
      4213 7292
TIME...MOT...LOC 0429Z 269DEG 37KT 4219 7266 4189 7260 4175 7275 

$$

Loconto

Area Forecast Discussion
National Weather Service Boston/Norton MA
721 PM EDT Wed Apr 15 2026

.WHAT HAS CHANGED...
No significant changes.

&&

.KEY MESSAGES...

- Backdoor front brings cooling near coast but warmth continues
  inland through Friday.

- Rounds of showers and thunderstorms this afternoon, later tonight,
  and again Thursday night.

- Pattern turns cooler early next week.

&&

.DISCUSSION...
KEY MESSAGE 1...Backdoor front brings cooling near coast but warmth
continues inland through Friday.

Backdoor front dropping southward will bring cooler temperatures at
least to eastern MA coast as winds turn onshore, but warmer
temperatures will persist inland. Front itself should meander over
southern New England for next couple of days, probably settling near
a line from Fitchburg to Norwood and Plymouth later this afternoon,
retreating back north overnight, then dropping back southward again
Thursday afternoon to about the same location. This certainly
presents a big challenge with the temperature forecast, less so in
CT and western MA which are more likely to maintain summertime
warmth through Friday, but less so across RI and eastern MA
depending upon exactly where front ends up and with its timing.

KEY MESSAGE 2...Rounds of showers and thunderstorms this afternoon,
later tonight, and again late Thursday.

As front remains over or near southern New England, a series of weak
low pressure centers will ride along it, each bringing chances of
showers and embedded thunderstorms.

First round through early tonight looks to be more scattered in
nature per high-res guidance. Already seeing CU development
upstream across central NY where instability is increasing so
that is where convective initiation should take place.

Environment here will feature strong 0-6km shear and reasonably
strong mid level lapse rates (6C/km) but best instability (1000
J/kg) is focused over western MA/CT which makes sense given
that is the area to the west of the front. While we don't expect
to see as much activity as we did Tuesday evening, there could
still be a few storms between 4 PM and 8 PM, perhaps even a few
hours later than that, capable of producing wind damage,
especially in CT per HREF helicity swaths.

Farther east in the cooler airmass, there is virtually no surface
instability but perhaps enough instability aloft coupled with
heating to pop up a few brief showers.

Next round of showers and embedded thunderstorms arrives during the
overnight hours ahead of weak short wave and weak surface low riding
along front. We still have strong 0-6km shear and decent mid level
lapse rates approaching 7C/km, but instability is aloft and would
support more in way of elevated thunder, not surface based, so
overall severe threat is low.

Once low moves offshore, it should drop front southward Thu morning
before it retreats northward again in afternoon. We then remain
under large scale subsidence until next stronger short wave
approaches Thu night. Environment remains about same with greatest
instability west of I-91 but continued presence of strong 0-6km
shear and decent mid level lapse rates of 6-7C/km. Guidance shows
showers and thunderstorms forming to out west during the day, which
arrives here Thu night and weakens as it does so.

KEY MESSAGE 3...Pattern turns cooler early next week.

It's been said all good things must come to an end, and for
those who have been enjoying this early taste of summer, a brief
pattern change will bring a return to much cooler weather early
next week.

A strong cold front crosses southern New England Sun followed
by a deep upper trough rotating through region, bringing an
anomalously cold airmass back into the region, albeit for a
short time. Temperatures aloft drop to as low as -7C to -10C at
850 mb Mon morning, only supporting highs in 40s and 50s Mon.

It might not be want you want but high pressure covering much of
eastern U.S. eventually shifts offshore by midweek as upper
flow becomes more zonal, allowing for a slow warming trend.
Highs should get back into 60s by Wed.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
Forecaster Confidence Levels...

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

00Z TAFs: Moderate confidence.

IFR-LIFR stratus and fog along the eastern MA coast will push a
bit further inland into portions of central MA and RI overnight
with lowest vsbys along the coast. Mainly VFR in the CT valley.
Expecting scattered showers and embedded thunderstorms
developing overnight.

Similar situation Thu. VFR inland with SW winds, and MVFR/IFR to
start closer to coast with E/NE winds, but even these areas should
improve to VFR Thu afternoon. Next round of scattered showers and
thunderstorms should hold off until Thu night.

KBOS Terminal... Moderate confidence in TAF. LIFR fog and
stratus tonight. May see some vsby improvement overnight with
any showers that move through. Conditions should improve to VFR
by midday Thu.

KBDL Terminal... High confidence in TAF.

Outlook /Thursday Night through Monday/...

Friday: VFR. Chance SHRA, slight chance TSRA.

Friday Night through Saturday: Mainly VFR, with local MVFR
possible.

Saturday Night: Mainly VFR, with local IFR possible. Breezy.
Slight chance SHRA.

Sunday: Mainly VFR, with local IFR possible. Breezy. SHRA
likely.

Sunday Night: VFR. Breezy. Chance SHRA.

Monday: VFR. Breezy. Slight chance SHRA.

&&

.MARINE...
Forecaster Confidence Levels...

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

High confidence through the weekend.

Backdoor front meandering over southern New England through Fri will
maintain light winds and calm seas, though there will be wind shifts
from SW to NE from time to time on eastern MA waters along with
showers and embedded thunderstorms.

Passage of stronger cold Front Sun should bring SCA conditions to at
least outer waters Sun into Mon.

Outlook /Thursday Night through Monday/...

Friday: Winds less than 25 kt. Seas locally approaching 5 ft.
Chance of rain showers.

Friday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Slight chance of rain showers.

Saturday: Winds less than 25 kt.

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

Sunday: Winds less than 25 kt. Seas locally approaching 5 ft.
Chance of rain showers.

Sunday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Local rough seas. Chance of rain showers.

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

&&

.CLIMATE...
Today's record highs (April 15):

Boston 82 in 1896
Hartford 88 in 1941
Providence 82 in 1938
Worcester 85 in 1941

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.

&&

DISCUSSION...JWD
AVIATION...KJC/JWD
MARINE...JWD
CLIMATE...