Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 87, NWS Boston/Norton, MA
NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 23, 2021, 3:28 PM EDT for Essex County, Middlesex County, Suffolk County, Massachusetts. It was in force for 47 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
- Jul 23, 2021, 3:28 PM EDT (19:28 UTC)
- Expired
- Jul 23, 2021, 4:15 PM EDT
- In force
- 47 min
- Issued by
- NWS Boston/Norton, MA
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Essex County, MA, Middlesex County, MA, Suffolk County, MA
The radar
The Boston radar (KBOX), 60 km from the middle of the area, began a volume at 19:30 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 nearest sounding before it
Gray, ME (KGYX), launched 12:00Z, 7.5 hours before the alert went out and 166 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
- 16 J/kg
- Mixed-layer CIN
- -94 J/kg
- Mixed-layer LCL
- 1504 m above ground
- 0-6 km bulk shear
- 10 kt
- 0-1 km storm-relative helicity
- -19 m²/s²
- 0-3 km storm-relative helicity
- -5 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
427
WUUS51 KBOX 231928
SVRBOX
MAC009-017-025-232015-
/O.NEW.KBOX.SV.W.0087.210723T1928Z-210723T2015Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
328 PM EDT Fri Jul 23 2021
The National Weather Service in Boston/Norton has issued a
* Severe Thunderstorm Warning for...
North central Suffolk County in eastern Massachusetts...
South central Essex County in northeastern Massachusetts...
Eastern Middlesex County in northeastern Massachusetts...
* Until 415 PM EDT.
* At 327 PM EDT, a severe thunderstorm was located over Danvers,
moving south at 15 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Expect wind damage to trees and power lines. Minor hail
damage to vehicles is possible.
* Locations impacted include...
Boston, Lynn, Revere, Peabody, Salem, Beverly, Chelsea, North
Andover, Saugus, Danvers, Marblehead, Winthrop, North Reading,
Swampscott, Ipswich, Lynnfield, Middleton, Georgetown, Boxford and
Hamilton.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.
&&
LAT...LON 4253 7078 4255 7082 4254 7090 4253 7088
4250 7089 4252 7085 4250 7085 4246 7094
4243 7092 4245 7094 4245 7097 4241 7099
4232 7093 4233 7096 4237 7098 4236 7101
4238 7100 4238 7101 4271 7108 4273 7092
TIME...MOT...LOC 1927Z 339DEG 14KT 4257 7095
HAIL...1.00IN
WIND...60MPH
$$
Loconto/Gaucher2 follow-up statements
370
WWUS51 KBOX 231958
SVSBOX
Severe Weather Statement
National Weather Service Boston/Norton MA
358 PM EDT Fri Jul 23 2021
MAC017-025-232007-
/O.CAN.KBOX.SV.W.0087.000000T0000Z-210723T2015Z/
Suffolk MA-Middlesex MA-
358 PM EDT Fri Jul 23 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL SUFFOLK AND
EASTERN MIDDLESEX COUNTIES IS CANCELLED...
The severe thunderstorm which prompted the warning has moved away
from the warned area. Therefore, the warning has been cancelled.
LAT...LON 4259 7102 4265 7086 4253 7078 4255 7082
4254 7090 4253 7088 4250 7089 4252 7085
4250 7085 4246 7094 4243 7092 4245 7094
4245 7096
TIME...MOT...LOC 1957Z 333DEG 11KT 4253 7090
$$
MAC009-232015-
/O.CON.KBOX.SV.W.0087.000000T0000Z-210723T2015Z/
Essex MA-
358 PM EDT Fri Jul 23 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM EDT
FOR SOUTH CENTRAL ESSEX COUNTY...
At 357 PM EDT, a severe thunderstorm was located over Salem, moving
southeast at 15 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Expect damage to trees and power lines.
Locations impacted include...
Lynn, Peabody, Salem, Beverly, Danvers, Marblehead, Swampscott,
Middleton, Hamilton, Topsfield, Wenham and Nahant.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.
&&
LAT...LON 4259 7102 4265 7086 4253 7078 4255 7082
4254 7090 4253 7088 4250 7089 4252 7085
4250 7085 4246 7094 4243 7092 4245 7094
4245 7096
TIME...MOT...LOC 1957Z 333DEG 11KT 4253 7090
HAIL...0.75IN
WIND...60MPH
$$
Loconto510
WWUS51 KBOX 232005
SVSBOX
Severe Weather Statement
National Weather Service Boston/Norton MA
405 PM EDT Fri Jul 23 2021
MAC009-232015-
/O.EXP.KBOX.SV.W.0087.000000T0000Z-210723T2015Z/
Essex MA-
405 PM EDT Fri Jul 23 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL ESSEX COUNTY
WILL EXPIRE AT 415 PM EDT...
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.
LAT...LON 4259 7102 4265 7086 4253 7078 4255 7082
4254 7090 4253 7088 4250 7089 4252 7085
4250 7085 4246 7094 4243 7092 4245 7094
4245 7096
TIME...MOT...LOC 2005Z 339DEG 14KT 4252 7089
$$
LocontoThe office that day
Everything else NWS Boston/Norton, MA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 23, 2:28 PM EDT | Special Weather Statement | BOX | Middlesex | 32 min |
| Jul 23, 2:49 PM EDT | Coastal Flood Statement | BOX | Barnstable, Essex, Nantucket, Norfolk, Plymouth, Suffolk | 11 hr |
| Jul 23, 3:04 PM EDT | Special Weather Statement | BOX | Essex | 26 min |
| Jul 23, 3:29 PM EDT | Special Marine Warning | BOX | 61 min | |
| Jul 23, 4:41 PM EDT | Special Weather Statement | BOX | Essex | 34 min |
| Jul 23, 4:57 PM EDT | Severe Thunderstorm Warning | BOX | Essex, Middlesex | 63 min |
| Jul 23, 5:23 PM EDT | Special Weather Statement | BOX | Bristol | 52 min |
| Jul 23, 5:50 PM EDT | Special Marine Warning | BOX | 55 min | |
| Jul 23, 6:09 PM EDT | Severe Thunderstorm Warning | BOX | Bristol, Plymouth | 26 min |
| Jul 23, 6:25 PM EDT | Special Weather Statement | BOX | Plymouth | 50 min |
| Jul 23, 6:32 PM EDT | Special Weather Statement | BOX | Worcester | 43 min |
| Jul 23, 6:42 PM EDT | Severe Thunderstorm Warning | BOX | Bristol, Norfolk, Plymouth | 48 min |
| Jul 23, 7:28 PM EDT | Severe Thunderstorm Warning | BOX | Plymouth | 34 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.