Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 74, NWS Boston/Norton, MA
NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 16, 2021, 5:47 PM EDT for 6 counties in Massachusetts; Providence County, Rhode Island. It was in force for 33 min. 1 report 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, 2021, 5:47 PM EDT (21:47 UTC)
- Expired
- Jul 16, 2021, 6:20 PM EDT
- In force
- 33 min
- Issued by
- NWS Boston/Norton, MA
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Bristol County, MA, Middlesex County, MA, Norfolk County, MA, Plymouth County, MA, Suffolk County, MA, Worcester County, MA, Providence County, RI
The radar
The Boston radar (KBOX), 29 km from the middle of the area, began a volume at 21:48 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, 5:55 PM EDT | TSTM WND DMG | Medway, MA | TREE DOWN ON PUDDINGHOUSE LANE. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Gray, ME (KGYX), launched 12:00Z, 9.8 hours before the alert went out and 198 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
- 153 J/kg
- Mixed-layer CIN
- -98 J/kg
- Mixed-layer LCL
- 1157 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- 103 m²/s²
- 0-3 km storm-relative helicity
- 146 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
718
WUUS51 KBOX 162147
SVRBOX
MAC005-017-021-023-025-027-RIC007-162245-
/O.NEW.KBOX.SV.W.0074.210716T2147Z-210716T2245Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
547 PM EDT Fri Jul 16 2021
The National Weather Service in Boston/Norton has issued a
* Severe Thunderstorm Warning for...
Southwestern Suffolk County in eastern Massachusetts...
Norfolk County in eastern Massachusetts...
Southeastern Worcester County in central Massachusetts...
South central Middlesex County in northeastern Massachusetts...
Northwestern Plymouth County in southeastern Massachusetts...
Northwestern Bristol County in southeastern Massachusetts...
Northwestern Providence County in Rhode Island...
* Until 645 PM EDT.
* At 546 PM EDT, severe thunderstorms were located along a line
extending from Dover to Norfolk to Franklin to Uxbridge, moving
east at 30 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to trees and power lines.
* Locations impacted include...
Boston, Brockton, Quincy, Weymouth, Woonsocket, Braintree,
Cumberland, Randolph, Franklin, Needham, North Attleborough,
Norwood, Milford, Milton, Stoughton, Marshfield, Dedham, Walpole,
Mansfield and Easton.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4203 7105 4195 7171 4212 7169 4218 7142
4226 7127 4229 7102 4226 7097 4230 7093
4225 7096 4227 7093 4225 7088 4231 7088
4226 7086 4225 7077 4220 7072 4221 7071
4220 7071 4217 7073 4211 7066
TIME...MOT...LOC 2146Z 266DEG 26KT 4222 7126 4213 7133 4208 7140 4204
7163
HAIL...<.75IN
WIND...60MPH
$$
Nocera/Gaucher1 follow-up statement
715
WWUS51 KBOX 162220
SVSBOX
Severe Weather Statement
National Weather Service Boston/Norton MA
620 PM EDT Fri Jul 16 2021
MAC005-017-021-023-025-027-RIC007-162230-
/O.CAN.KBOX.SV.W.0074.000000T0000Z-210716T2245Z/
Suffolk MA-Norfolk MA-Worcester MA-Middlesex MA-Plymouth MA-
Bristol MA-Providence RI-
620 PM EDT Fri Jul 16 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN SUFFOLK...
NORFOLK...SOUTHEASTERN WORCESTER...SOUTH CENTRAL MIDDLESEX...
NORTHWESTERN PLYMOUTH...NORTHWESTERN BRISTOL AND NORTHWESTERN
PROVIDENCE COUNTIES IS CANCELLED...
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning has been cancelled. However gusty winds and
heavy rain are still possible with these thunderstorms.
LAT...LON 4203 7105 4195 7171 4212 7169 4218 7142
4226 7127 4229 7102 4226 7097 4230 7093
4225 7096 4227 7093 4225 7088 4231 7088
4226 7086 4225 7077 4220 7072 4221 7071
4220 7071 4217 7073 4211 7066
TIME...MOT...LOC 2218Z 266DEG 26KT 4224 7095 4215 7102 4210 7109 4206
7132
$$The office that day
Everything else NWS Boston/Norton, MA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 16, 9:38 AM EDT | Heat Advisory | BOX | Bristol, Essex, Middlesex, Norfolk, Plymouth, Suffolk | 9 hr |
| Jul 16, 2:59 PM EDT | Flash Flood Watch | BOX | Franklin, Hampden, Hampshire, Worcester | 56 hr |
| Jul 16, 3:04 PM EDT | Severe Thunderstorm Warning | BOX | Norfolk, Worcester | 56 min |
| Jul 16, 3:41 PM EDT | Special Weather Statement | BOX | Hampden | 49 min |
| Jul 16, 4:26 PM EDT | Special Weather Statement | BOX | Norfolk, Suffolk | 49 min |
| Jul 16, 4:36 PM EDT | Severe Thunderstorm Warning | BOX | Middlesex, Norfolk, Worcester | 35 min |
| Jul 16, 4:50 PM EDT | Special Marine Warning | BOX | 55 min | |
| Jul 16, 5:05 PM EDT | Severe Thunderstorm Warning | BOX | Hampden, Worcester | 55 min |
| Jul 16, 6:32 PM EDT | Special Marine Warning | BOX | 43 min | |
| Jul 16, 6:17 PM EDT | Special Weather Statement | BOX | Bristol, Kent, Providence | 58 min |
Nearby
Severe Thunderstorm Warnings in Massachusetts, 2021Severe Thunderstorm Warnings in Rhode Island, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.