Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 37, NWS Boston/Norton, MA

July 16, 2026Essex County, Middlesex County, Worcester County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 16, 2026, 5:23 PM EDT for Essex County, Middlesex County, Worcester County, Massachusetts. It was in force for 37 min. 7 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 16, 2026, 5:23 PM EDT (21:23 UTC)
Expired: Jul 16, 2026, 6:00 PM EDT
In force: 37 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Essex County, MA, Middlesex County, MA, Worcester County, MA

The radar

The Boston radar (KBOX), 73 km from the middle of the area, began a volume at 21:26 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Jul 16, 5:38 PM EDT	TSTM WND DMG	Chelmsford, MA	Tree down on wires. Power outage in the area.
Jul 16, 5:50 PM EDT	TSTM WND DMG	Bedford, MA	Tree down blocking road behind the Bank of America.
Jul 16, 5:50 PM EDT	TSTM WND DMG	Concord, MA	Large tree into the power lines on Old Bridge Road.
Jul 16, 5:50 PM EDT	TSTM WND DMG	Lowell, MA	Large tree branch & wires down on 951 Broadway street.
Jul 16, 5:51 PM EDT	TSTM WND DMG	Stoneham, MA	Tree down blocking road at 8 Rebecca Lane.
Jul 16, 5:52 PM EDT	TSTM WND DMG	Pepperell, MA	Large tree blocking road at Townsend St (Rte 113) and South Road (Rte 119).
Jul 16, 5:54 PM EDT	TSTM WND DMG	Wilmington, MA	Large Tree branch down blocking the road at 3 Feurgeson Road.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 8 storm reports to this severe thunderstorm warning; the first came 15 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Gray, ME (KGYX), launched 12:00Z, 9.4 hours before the alert went out and 162 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 3 J/kg
Mixed-layer CIN: -77 J/kg
Mixed-layer LCL: 1646 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 76 m²/s²
0-3 km storm-relative helicity: 127 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

721 
WUUS51 KBOX 162123
SVRBOX
MAC009-017-027-162200-
/O.NEW.KBOX.SV.W.0037.260716T2123Z-260716T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
523 PM EDT Thu Jul 16 2026

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Southwestern Essex County in northeastern Massachusetts...
  Northeastern Worcester County in central Massachusetts...
  Northern Middlesex County in northeastern Massachusetts...

* Until 600 PM EDT.

* At 521 PM EDT, severe thunderstorms were located along a line
  extending from Salem to Sharon, moving southeast at 45 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Expect damage to trees and power lines. Little to no 
           lightning expected.

* Locations impacted include...
  Lowell, Lynn, Lawrence, Peabody, Methuen, Salem, Fitchburg,
  Billerica, Beverly, Woburn, Chelmsford, Andover, Lexington, Dracut,
  Tewksbury, North Andover, Melrose, Saugus, Danvers, and Wakefield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4265 7111 4251 7075 4249 7078 4244 7149
      4271 7191 4270 7129 4273 7126
TIME...MOT...LOC 2121Z 305DEG 38KT 4281 7121 4281 7196 

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

$$

EM

1 follow-up statement

139 
WWUS51 KBOX 162202
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
602 PM EDT Thu Jul 16 2026

MAC009-017-027-162212-
/O.EXP.KBOX.SV.W.0037.000000T0000Z-260716T2200Z/
Essex MA-Worcester MA-Middlesex MA-
602 PM EDT Thu Jul 16 2026

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN ESSEX...
NORTHEASTERN WORCESTER AND NORTHERN MIDDLESEX COUNTIES HAS EXPIRED...

The storms which prompted the warning have moved out of the area.
Therefore, the warning has been allowed to expire.  However gusty
winds are still possible with these thunderstorms.

Remember, a Severe Thunderstorm Warning still remains in effect for
eastern Essex County.

LAT...LON 4265 7111 4251 7075 4249 7078 4244 7149
      4271 7191 4270 7129 4273 7126
TIME...MOT...LOC 2202Z 305DEG 38KT 4258 7076 4258 7151 

$$

EM

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Boston/Norton, MA wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 16, 3:14 PM EDT, 2 hours 9 minutes earlier. Its key messages:

A few brief spot showers possible across northern MA into mid- evening. Otherwise...dry and pleasant through Fri night outside of the wildfire smoke this evening. Lows mainly in the 50s to the lower 60s. Highs Fri mainly in the lower to middle 80s.
Chances for beneficial showers and thunderstorms on the uptake for Saturday PM into the overnight period.
A cooler start to the work week with unsettled conditions through the middle of next week.

Area forecast discussion, Jul 16, 3:14 PM EDT, 2 hours 9 minutes before

Area Forecast Discussion
National Weather Service Boston/Norton MA
314 PM EDT Thu Jul 16 2026

.WHAT HAS CHANGED...

No significant changes have been made to the forecast.

&&

.KEY MESSAGES...

- A few brief spot showers possible across northern MA into mid-
  evening. Otherwise...dry and pleasant through Fri night outside
  of the wildfire smoke this evening. Lows mainly in the 50s to the
  lower 60s. Highs Fri mainly in the lower to middle 80s.

- Chances for beneficial showers and thunderstorms on the uptake for
  Saturday PM into the overnight period.

- A cooler start to the work week with unsettled conditions
  through the middle of next week.

&&

.DISCUSSION...

KEY MESSAGE 1...A few brief spot showers possible across northern MA
into mid-evening. Otherwise...dry and pleasant through Fri night
outside of the wildfire smoke this evening. Lows mainly in the 50s to
the lower 60s. Highs Fri mainly in the lower to middle 80s.

A cold front will cross the region this evening. However...the lack
of low level moisture coupled with the main shortwave forcing
passing to our north will keep most of us dry. A few brief spot
showers may survive into northern MA and perhaps the remote risk for
a rumble of thunder in far northeast MA. Otherwise...generally a
dry/very pleasant weather through Friday night. We will have to deal
with some more smoke moving into the region through late
afternoon...But the worst of it will likely stay to our southwest.
And the good news is that it will get shoved into the mid-Atlantic
after midnight and will not be an issue for Fri.

High pressure builds across the region on Friday behind tonight/s
cold frontal passage. This high pressure system will shift east of
us Friday night...But we will maintain dry/pleasant weather. Highs
on Friday will mainly be in the lower to middle 80s with plenty of
sunshine and comfortable humidity. Lows tonight and Friday night
will mainly be in the 50s to the lower 60s with middle 60s in the
urban heat island of Boston.

KEY MESSAGE 2...Chances for beneficial showers and thunderstorms on
the uptake for Saturday PM into the overnight period.

Chances for showers and thunderstorms begin to increase heading into
the weekend as a surface low approaches Saturday, bringing prolonged
southwesterly flow and surging PWATs. Latest guidance suite has
increased confidence in PWATs over 2.0", with some as high as 3.0",
which lends favor to some heavy downpours developing overnight.
ECMWF and CMC ensembles indicate a 60-80% chance of at least 0.5" of
QPF (mostly across the southern coastal areas and up into central CT
and RI), while the GFS ensemble is trending those higher percentiles
off our southern shores and further north into northern New England.
Southern New England is currently in a Marginal (1/4) risk for flash
flooding, but discussion has started with neighboring offices (and
will continue with the next forecast cycle) on potentially
increasing that risk to a Sight (2/4), particularly across the
southern coastal areas of CT and RI given the relatively high
consensus in the model guidance that some heavier bands could
develop across those areas.

Instability profiles continue to look relatively weak, but CSU
Machine Learning probabilities continue to indicate low (5-15%)
chances that some storms could turn severe.

KEY MESSAGE 3...A cooler start to the work week with unsettled
conditions through the middle of next week.

A cooler airmass moves in Sunday once the cold front pushes
offshore, with temperatures making a return to seasonable norms...
in the low to mid 80s through at least the middle of next week. A
brief spell of drier conditions is possible Monday as high pressure
builds somewhere over the Appalachian region. Chances for showers
then increase again for the middle of next week as a surface low
moves east across Ontario and a trailing cold front sweeps through
the mid-Atlantic region into New England.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
Forecaster Confidence Levels...

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

18z TAF Update...

Tonight through Friday night...High confidence.

VFR through Friday night except for areas of smoke this evening and
perhaps a few brief spot showers across northern MA. We will be on
the northeast edge of the smoke...so not sure visibility will be
reduced that much but may see a period of MVFR vsbys with the
greatest risk of reductions southwest of a KBDL to KPVD line. This
smoke should be shoved into the mid-Atlantic after midnight into Fri
behind this evening/s cold front.

W wind gusts 25+ knots diminish this evening. NW winds 10 knots or
less overnight into Friday morning before they shift to the SW by
mid-late Friday afternoon. A few hours of sea breeze conditions are
also possible Friday afternoon along portions of the immediate
coast.

KBOS Terminal...High confidence in TAF. Main risk of MVFR vsbys in
smoke will be southwest of the terminal this evening...But can not
rule out the low risk for it briefly occurring at KBOS.

KBDL Terminal...High confidence in TAF. We may see some MVFR vsbys
flirt with the terminal this evening before pushing southwest.

Outlook /Saturday through Tuesday/...

Saturday: Mainly VFR, with local MVFR possible. Breezy. Chance
SHRA, chance TSRA.

Saturday Night: MVFR/IFR conditions possible. Windy with local
gusts up to 30 kt. SHRA, slight chance TSRA.

Sunday: VFR. Breezy.

Sunday Night through Monday Night: VFR.

Tuesday: Mainly VFR, with local IFR possible. Breezy. Chance
SHRA, chance TSRA.

&&

.MARINE...

Forecaster Confidence Levels...

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

Tonight through Friday night...High confidence.

Gusty near shore small craft W wind gusts will diminish this evening
and shift to the NW behind the cold front. Otherwise...high pressure
builds in from the west behind this evening/s cold front keeping
winds/seas below small craft advisory thresholds.

Outlook /Saturday through Tuesday/...

Saturday: Low risk for Small Craft Advisory winds with gusts up
to 30 kt. Seas locally approaching 5 ft. Chance of rain
showers.

Saturday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 30 kt. Seas up to 5 ft. Rain showers, slight
chance of thunderstorms.

Sunday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Areas of rough seas.

Sunday Night: Winds less than 25 kt. Areas of rough seas.

Monday: Winds less than 25 kt. Seas up to 5 ft.

Monday Night: Winds less than 25 kt. Areas of seas approaching
5 ft. Slight chance of rain showers.

Tuesday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Local rough seas. Chance of rain showers, slight
chance of thunderstorms.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Air Quality Alert until midnight EDT tonight for CTZ002>004.
MA...Air Quality Alert until midnight EDT tonight for MAZ002>024-
     026.
RI...Air Quality Alert until midnight EDT tonight for RIZ001>008.
MARINE...Small Craft Advisory until 8 PM EDT this evening for
     ANZ230>237-250-251-254>256.

&&

DISCUSSION...Frank/McMinn
AVIATION...Frank/McMinn
MARINE...Frank/McMinn

The office that day

Everything else NWS Boston/Norton, MA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 16, 2:37 AM EDT	Small Craft Advisory	BOX		17 hr
Jul 16, 4:43 PM EDT	Special Marine Warning	BOX		62 min
Jul 16, 4:58 PM EDT	Severe Thunderstorm Warning	BOX	Essex	47 min
Jul 16, 5:47 PM EDT	Severe Thunderstorm Warning	BOX	Essex	34 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2026 Every severe thunderstorm warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.