Severe Thunderstorm Warning 1, NWS Boston/Norton, MA

237 
WWUS51 KBOX 010111
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
911 PM EDT Tue Mar 31 2026

MAC013-015-010120-
/O.CAN.KBOX.SV.W.0001.000000T0000Z-260401T0145Z/
Hampshire MA-Hampden MA-
911 PM EDT Tue Mar 31 2026

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN HAMPSHIRE AND
NORTHWESTERN HAMPDEN COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

LAT...LON 4272 7227 4263 7228 4242 7237 4241 7248
      4243 7249 4243 7252 4241 7270 4245 7270
      4245 7277 4247 7277 4248 7282 4255 7279
      4273 7278
TIME...MOT...LOC 0110Z 256DEG 37KT 4281 7263 4261 7269 4241 7277 

$$

MAC011-027-010145-
/O.CON.KBOX.SV.W.0001.000000T0000Z-260401T0145Z/
Worcester MA-Franklin MA-
911 PM EDT Tue Mar 31 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM EDT
FOR NORTHWESTERN WORCESTER AND FRANKLIN COUNTIES...

At 910 PM EDT, severe thunderstorms were located along a line
extending from Guilford Center to Shelburne to near Williamsburg,
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...
Greenfield, Orange, Deerfield, Montague, Sunderland, Northfield,
Bernardston, Buckland, Conway, Shelburne, Leverett, Erving,
Shutesbury, Ashfield, Colrain, Gill, Whately, Charlemont, Royalston,
and Goshen.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4272 7227 4263 7228 4242 7237 4241 7248
      4243 7249 4243 7252 4241 7270 4245 7270
      4245 7277 4247 7277 4248 7282 4255 7279
      4273 7278
TIME...MOT...LOC 0110Z 256DEG 37KT 4281 7263 4261 7269 4241 7277 

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

$$

EM

001 
WWUS51 KBOX 010130
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
930 PM EDT Tue Mar 31 2026

MAC011-027-010139-
/O.CAN.KBOX.SV.W.0001.000000T0000Z-260401T0145Z/
Worcester MA-Franklin MA-
930 PM EDT Tue Mar 31 2026

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN WORCESTER AND
FRANKLIN COUNTIES IS CANCELLED...

The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore, the warning has
been cancelled.

LAT...LON 4272 7227 4263 7228 4242 7237 4241 7248
      4243 7249 4243 7252 4241 7270 4245 7270
      4245 7277 4247 7277 4248 7282 4255 7279
      4273 7278
TIME...MOT...LOC 0128Z 256DEG 37KT 4286 7238 4266 7244 4246 7252 

$$

EM

Area Forecast Discussion
National Weather Service Boston/Norton MA
733 PM EDT Tue Mar 31 2026

.WHAT HAS CHANGED...
Updated Aviation section.

There is a marginal risk for a strong to severe thunderstorm
this evening, mainly across western MA and CT.

&&

.KEY MESSAGES...

- Scattered showers and thunderstorms this evening with a strong to
severe storm possible over western MA

- Unsettled weather continues into Wednesday and Wednesday Night

- Milder and unsettled pattern later this week brings showers from
time to time along with warmer temperatures for inland locations.

&&

.DISCUSSION...
KEY MESSAGE 1...Scattered showers and thunderstorms this evening
with a strong to severe storm possible over western MA

Short-wave energy embedded within larger scale zonal flow aloft
will help trigger showers and thunderstorms this evening over
western MA/CT. The latest Convective Outlook from The Storm
Prediction Center places western MA and CT in a marginal risk
for severe storm with a general thunderstorm risk elsewhere in
southern New England.

The overall strength of synoptic forcing for ascent in the
atmosphere will be on the weak side tonight. Furthermore,
instability will be limited to the tune of 250-500 J/Kg of
MLCAPE. While sufficient for thunderstorm development, these
numbers do not present an alarming scenario for severe weather.
Deep layer shear will be strong with 40-50 knots of shear in
the 0-6 km layer. Thus, we have the ingredients needed for a
period of convection.

If we consult the latest suite of hi- resolution model
guidance, we find that 00-06Z (8PM-2AM), will be the best
opportunity for thunderstorms across southern New England. Hi-
res guidance keeps the most robust activity mainly along and
north of the I-90 corridor. CSU ML probabilities give a 5-10%
chance of severe thunderstorm wind gusts or large hail for
western MA. Further east, lightning and periods of heavy
rainfall would be the most likely hazards. Expect thunderstorm activity
to wane after midnight as instability diminishes.

KEY MESSAGE 2...Unsettled weather continues into Wednesday and
Wednesday Night

A wind shift to the west/southwest early Wednesday will support
another mild afternoon in southern New England with many
locations reaching the upper 60s to low 70s. The presence of a
frontal wave moving over The Northeast will continue to keep
things unsettled with intermittent periods of showers expected
during the day Wednesday. A lull in shower activity is expected
Wednesday afternoon, but a cold front sagging south will
support an additional round of showers Wednesday night into
Thursday, mainly along and south of the I-90 corridor. Latest
model guidance resolves the most shower activity over the south
coast of MA and RI. Chillier temperatures settle in Wednesday
night with lows temperatures falling to the 30s by Thursday
morning.

KEY MESSAGE 3...Milder and unsettled pattern later this week brings
showers from time to time along with warmer temperatures for inland
locations.

Beyond Wednesday we're in for a big cooldown as 1040mb high pressure
moves into Nova Scotia and surface winds veer to the northeast
pushing a cold front the rest of the way through the region. This,
combined with stubborn low clouds will keep high temperatures very
cold compared to Wednesday, in the upper 30s and low 40s. This will
be a 30 degree difference in high temperatures for some locations!
The roller coaster continues on Friday as the front lifts back to
the north bringing warmer temps in the 60s and even some 70s by the
weekend. That being said, it remains a very chaotic and dynamic
pattern with SNE sandwiched between a subtropical ridge and east
coast trough so confidence in the temperature forecast is low to
moderate. Same with exact timing and placement of any rainfall
associated with these frontal passages and passing shortwaves. A
generally unsettled pattern with scattered rain showers looks to
hold on through the early part of the weekend before a more
appreciable front and mid level trough move through around
Sunday/Sunday night.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

00Z TAF Update...Moderate confidence.

Backdoor front was settling near a line from ORE-PVD this
evening. MVFR/IFR ceilings with NE winds in its wake will
improve overnight once front lifts back to north. VFR to west of
front with S winds. Watching TSRA moving through eastern NY
which should weaken as it reaches SNE, mainly bringing SHRA and
an embedded TS along and north of I-90 until around midnight.

LLWS expected overnight, especially near coast, with 020 winds
230-240/50-60kt.

Scattered showers expected Wed morning with S/SW winds, then
backdoor front once again drops S during afternoon and evening,
this time to more of southern New England, with wind shift to
N/NE and lowering ceilings to MVFR/IFR. Also expecting a period
of showers, mainly focused near South Coast, later in day.

KBOS Terminal...Moderate confidence in TAF. Timing of
improvement later tonight may be too quick and there is lower
confidence on whether or not IFR cigs return Wed afternoon.

KBDL Terminal...Moderate confidence in TAF but low confidence in
timing of any isolated t-storm risk.

Outlook /Wednesday Night through Sunday/...

Thursday: Mainly MVFR, with areas IFR possible. Breezy. Chance
RA, FZRA likely.

Thursday Night: Mainly MVFR, with areas IFR possible. Chance
RA.

Friday: Mainly VFR, with local IFR possible. Breezy.

Friday Night through Saturday: Breezy. Slight chance RA.

Saturday Night: Breezy. Chance RA.

Sunday: Windy with local gusts up to 30 kt. RA likely.

&&

.MARINE...
Forecaster Confidence Levels...

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

Moderate southwest winds overnight between 15 and 25 knots with
strongest winds over the outer south coastal waters. A few
marginal gale force gusts are possible. SCY in place through
tomorrow night. Seas remain elevated over the southern marine
zones as well but gradually subside from 7-10 feet Wednesday
morning to 4-6 feet by Wednesday evening. Winds shift to the
northeast Wednesday night into Thursday but remain moderately
strong with sustained winds between 15 and 20 knots.

Outlook /Wednesday Night through Sunday/...

Thursday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Seas up to 5 ft. Chance of rain.

Thursday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft. Chance of rain.

Friday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Areas of seas approaching 5 ft.

Friday Night: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft.

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

Saturday Night: Low risk for Small Craft Advisory winds with
local gusts up to 30 kt. Seas up to 5 ft. Slight chance of
rain.

Sunday: Strong winds with gusts up to 30 kt. Areas of rough
seas. Chance of rain.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ231-
     250.
     Small Craft Advisory until 7 PM EDT Wednesday for ANZ232>235-
     237.
     Small Craft Advisory until 2 PM EDT Wednesday for ANZ236.
     Small Craft Advisory until 6 AM EDT Thursday for ANZ254>256.

&&

DISCUSSION...BW/RM
AVIATION...JWD
MARINE...RM