Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 32, NWS Boston/Norton, MA
NWS Boston/Norton, MA issued this severe thunderstorm warning at Jun 30, 2021, 5:13 PM EDT for Middlesex County, Worcester County, Massachusetts. It was in force for 62 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Jun 30, 2021, 5:13 PM EDT (21:13 UTC)
- Expired
- Jun 30, 2021, 6:15 PM EDT
- In force
- 62 min
- Issued by
- NWS Boston/Norton, MA
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Middlesex County, MA, Worcester County, MA
The radar
The Boston radar (KBOX), 79 km from the middle of the area, began a volume at 21:13 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.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jun 30, 3:21 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Albany, NY (KALY), launched 12:00Z, 9.2 hours before the alert went out and 172 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.
- Mixed-layer CAPE
- 113 J/kg
- Mixed-layer CIN
- -257 J/kg
- Mixed-layer LCL
- 1162 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 66 m²/s²
- 0-3 km storm-relative helicity
- 98 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
623
WUUS51 KBOX 302113
SVRBOX
MAC017-027-302215-
/O.NEW.KBOX.SV.W.0032.210630T2113Z-210630T2215Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
513 PM EDT Wed Jun 30 2021
The National Weather Service in Boston/Norton has issued a
* Severe Thunderstorm Warning for...
Northeastern Worcester County in central Massachusetts...
Northwestern Middlesex County in northeastern Massachusetts...
* Until 615 PM EDT.
* At 513 PM EDT, a severe thunderstorm was located over Westminster,
or near Fitchburg, moving east at 25 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Trained weather spotters have reported a history of wind
damage with these storms.
IMPACT...Expect wind damage to trees and power lines. Minor hail
damage to vehicles is possible.
* Locations impacted include...
Leominster, Fitchburg, Westford, Acton, Gardner, Concord, Sudbury,
Holden, Clinton, Pepperell, Tyngsborough, Groton, Maynard,
Lunenburg, Townsend, Littleton, Lancaster, Rutland, Sterling and
Ayer.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4241 7198 4263 7193 4264 7142 4242 7141
TIME...MOT...LOC 2113Z 265DEG 21KT 4257 7187
HAIL...1.00IN
WIND...60MPH
$$
Frank2 follow-up statements
674
WWUS51 KBOX 302134
SVSBOX
Severe Weather Statement
National Weather Service Boston/Norton MA
534 PM EDT Wed Jun 30 2021
MAC017-027-302215-
/O.CON.KBOX.SV.W.0032.000000T0000Z-210630T2215Z/
Worcester MA-Middlesex MA-
534 PM EDT Wed Jun 30 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR NORTHEASTERN WORCESTER AND NORTH CENTRAL MIDDLESEX COUNTIES...
At 534 PM EDT, a severe thunderstorm was located over Harvard, or 8
miles east of Leominster, moving east at 20 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Trained weather spotters have reported a history of wind
damage with this storm.
IMPACT...Expect damage to trees and power lines.
Locations impacted include...
Leominster, Fitchburg, Westford, Acton, Concord, Sudbury, Holden,
Clinton, Pepperell, Tyngsborough, Groton, Maynard, Lunenburg,
Townsend, Littleton, Lancaster, Rutland, Sterling, Ayer and
Westminster.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4241 7198 4263 7174 4264 7142 4242 7141
TIME...MOT...LOC 2134Z 268DEG 13KT 4250 7161
HAIL...0.75IN
WIND...60MPH
$$
Frank210 WWUS51 KBOX 302206 SVSBOX Severe Weather Statement National Weather Service Boston/Norton MA 606 PM EDT Wed Jun 30 2021 MAC017-027-302215- /O.CON.KBOX.SV.W.0032.000000T0000Z-210630T2215Z/ Worcester MA-Middlesex MA- 606 PM EDT Wed Jun 30 2021 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT FOR EAST CENTRAL WORCESTER AND CENTRAL MIDDLESEX COUNTIES... At 605 PM EDT, a severe thunderstorm was located over Acton, or near Chelmsford, moving east at 35 mph. HAZARD...60 mph wind gusts. SOURCE...Radar indicated. IMPACT...Expect damage to trees and power lines. Locations impacted include... Westford, Acton, Concord, Sudbury, Groton, Maynard, Littleton, Ayer, Stow, Harvard, Boxborough and Bolton. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. && LAT...LON 4242 7164 4258 7155 4264 7142 4242 7141 TIME...MOT...LOC 2205Z 271DEG 37KT 4251 7140 HAIL...<.75IN WIND...60MPH $$ Frank
The office that day
Everything else NWS Boston/Norton, MA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 30, 2:29 AM EDT | Small Craft Advisory | BOX | 18 hr | |
| Jun 30, 3:40 PM EDT | Special Weather Statement | BOX | Hampshire | 65 min |
| Jun 30, 3:42 PM EDT | Special Weather Statement | BOX | Franklin | 63 min |
| Jun 30, 3:48 PM EDT | Severe Thunderstorm Warning | BOX | Franklin, Hampden, Hampshire | 57 min |
| Jun 30, 4:03 PM EDT | Severe Thunderstorm Warning | BOX | Franklin, Hampshire | 57 min |
| Jun 30, 4:32 PM EDT | Severe Thunderstorm Warning | BOX | Franklin, Middlesex, Worcester | 58 min |
| Jun 30, 4:39 PM EDT | Severe Thunderstorm Warning | BOX | Franklin, Hampden, Hampshire, Worcester | 66 min |
| Jun 30, 4:45 PM EDT | Tornado Warning | BOX | Franklin, Worcester | 26 min |
| Jun 30, 5:00 PM EDT | Severe Thunderstorm Warning | BOX | Middlesex, Worcester | 30 min |
| Jun 30, 5:25 PM EDT | Severe Thunderstorm Warning | BOX | Essex, Middlesex | 49 min |
| Jun 30, 5:26 PM EDT | Special Marine Warning | BOX | 64 min | |
| Jun 30, 5:29 PM EDT | Severe Thunderstorm Warning | BOX | Worcester | 44 min |
| Jun 30, 5:43 PM EDT | Severe Thunderstorm Warning | BOX | Essex, Middlesex | 51 min |
| Jun 30, 5:54 PM EDT | Severe Thunderstorm Warning | BOX | Middlesex, Norfolk, Suffolk, Worcester | 53 min |
| Jun 30, 5:58 PM EDT | Special Marine Warning | BOX | 62 min | |
| Jun 30, 6:11 PM EDT | Special Weather Statement | BOX | Norfolk | 49 min |
| Jun 30, 6:12 PM EDT | Severe Thunderstorm Warning | BOX | Middlesex, Norfolk, Plymouth, Suffolk, Worcester | 47 min |
| Jun 30, 6:22 PM EDT | Special Marine Warning | BOX | 53 min | |
| Jun 30, 6:31 PM EDT | Special Marine Warning | BOX | 59 min | |
| Jun 30, 6:45 PM EDT | Severe Thunderstorm Warning | BOX | Hampden | 60 min |
| Jun 30, 6:57 PM EDT | Special Marine Warning | BOX | 33 min | |
| Jun 30, 7:15 PM EDT | Severe Thunderstorm Warning | BOX | Hampden, Worcester | 60 min |
Nearby
Severe Thunderstorm Warnings in Massachusetts, 2021Every severe thunderstorm warning in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.