Alert archive / Massachusetts / Special Weather Statements in 2021
Special Weather Statement, NWS Boston/Norton, MA
NWS Boston/Norton, MA issued this special weather statement at Jul 21, 2021, 9:29 PM EDT for Plymouth County, Massachusetts. It was in force for 46 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 21, 2021, 9:29 PM EDT (01:29 UTC)
- Expired
- Jul 21, 2021, 10:15 PM EDT
- In force
- 46 min
- Issued by
- NWS Boston/Norton, MA
County Plymouth County, MA
The radar
The Boston radar (KBOX), 36 km from the middle of the area, began a volume at 01:30 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 00:00Z, 1.5 hours before the alert went out and 212 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
- 445 J/kg
- Mixed-layer CIN
- -27 J/kg
- Mixed-layer LCL
- 843 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- -15 m²/s²
- 0-3 km storm-relative helicity
- 42 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.2
The text
As transmitted.
723
WWUS81 KBOX 220129
SPSBOX
Special Weather Statement
National Weather Service Boston/Norton MA
929 PM EDT Wed Jul 21 2021
MAZ017>019-220215-
Eastern Plymouth MA-Northern Bristol MA-Western Plymouth MA-
929 PM EDT Wed Jul 21 2021
...STRONG THUNDERSTORMS PRODUCING TORRENTIAL RAINFALL IN BRISTOL
AND PLYMOUTH COUNTIES...
At 927 PM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Marshfield to near Rehoboth. Movement was
east at 20 mph.
Pea size hail and winds in excess of 30 mph will accompany these
storms. Torrential rainfall could lead to localized poor drainage
flooding.
Locations impacted include...
Brockton, Plymouth, Taunton, Bridgewater, Marshfield, Attleboro,
Middleborough, Easton, Norton, Scituate, Pembroke, Rockland,
Abington, Duxbury, Whitman, Hanover, East Bridgewater, Seekonk,
Raynham and Kingston.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Get indoors when these storms approach. Winds may be strong enough
to produce minor damage, such as a few downed branches. Do not drive
through flooded roadways.
Frequent lightning was occurring. Lightning can strike far away from
the storm. Go inside a building or vehicle. Wait at least 30 minutes
until after the storm has passed to resume outdoor activities.
&&
LAT...LON 4199 7063 4201 7071 4198 7066 4198 7065
4196 7066 4194 7062 4179 7094 4190 7133
4219 7075 4219 7072 4209 7064 4205 7066
4202 7062 4204 7065 4204 7066 4202 7068
4200 7064 4201 7060
TIME...MOT...LOC 0127Z 272DEG 17KT 4213 7068 4187 7120
$$
ChaiThe office that day
Everything else NWS Boston/Norton, MA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 21, 8:20 PM EDT | Special Weather Statement | BOX | Norfolk | 40 min |
| Jul 21, 8:27 PM EDT | Special Marine Warning | BOX | 63 min | |
| Jul 21, 8:30 PM EDT | Severe Thunderstorm Warning | BOX | Norfolk, Plymouth, Suffolk | 30 min |
| Jul 21, 8:42 PM EDT | Special Marine Warning | BOX | 63 min | |
| Jul 21, 8:46 PM EDT | Special Weather Statement | BOX | Plymouth | 44 min |
| Jul 21, 9:51 PM EDT | Special Marine Warning | BOX | 54 min | |
| Jul 21, 9:53 PM EDT | Special Weather Statement | BOX | Barnstable | 37 min |
Nearby
Special Weather Statements in Massachusetts, 2021Every special weather statement 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.