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 20, 2021, 10:39 PM EDT for Franklin County, Massachusetts. It was in force for 66 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 20, 2021, 10:39 PM EDT (02:39 UTC)
- Expired
- Jul 20, 2021, 11:45 PM EDT
- In force
- 66 min
- Issued by
- NWS Boston/Norton, MA
County Franklin County, MA
The radar
The Albany radar (KENX), 106 km from the middle of the area, began a volume at 02:43 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
Albany, NY (KALY), launched 00:00Z, 2.7 hours before the alert went out and 88 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
- 1226 J/kg
- Mixed-layer CIN
- -24 J/kg
- Mixed-layer LCL
- 1198 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 89 m²/s²
- 0-3 km storm-relative helicity
- 82 m²/s²
- Significant tornado parameter
- 0.4
- Supercell composite
- 4.6
The text
As transmitted.
350
WWUS81 KBOX 210239
SPSBOX
Special Weather Statement
National Weather Service Boston/Norton MA
1039 PM EDT Tue Jul 20 2021
MAZ002>004-008-210345-
Western Franklin MA-Western Hampshire MA-Northern Worcester MA-
Eastern Franklin MA-
1039 PM EDT Tue Jul 20 2021
...STRONG THUNDERSTORMS ENTERING HAMPSHIRE AND FRANKLIN COUNTIES...
At 1038 PM EDT, Doppler radar was tracking a strong thunderstorm over
East Windsor, or 13 miles east of Pittsfield, moving east at 40 mph.
Winds in excess of 40 mph will accompany this storm.
Locations impacted include...
Amherst, Greenfield, Orange, Deerfield, Montague, Sunderland,
Northfield, Williamsburg, Bernardston, Buckland, Conway, Shelburne,
Leverett, Erving, Shutesbury, Ashfield, Colrain, Gill, Whately and
Charlemont.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Get indoors when this storm approaches. Winds may be strong enough to
produce minor damage, such as a few downed branches.
&&
LAT...LON 4252 7297 4256 7298 4274 7279 4273 7240
4244 7224 4241 7300
TIME...MOT...LOC 0238Z 254DEG 33KT 4249 7300
$$
BWThe office that day
Everything else NWS Boston/Norton, MA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 20, 9:53 PM EDT | Severe Thunderstorm Warning | BOX | Franklin, Hampshire | 52 min |
| Jul 20, 11:03 PM EDT | Special Weather Statement | BOX | Worcester | 57 min |
| Jul 20, 11:53 PM EDT | Special Weather Statement | BOX | Worcester | 67 min |
| Jul 21, 12:02 AM EDT | Special Weather Statement | BOX | Essex | 58 min |
| Jul 21, 7:27 PM EDT | Special Marine Warning | BOX | 63 min | |
| Jul 21, 7:39 PM EDT | Special Marine Warning | BOX | 66 min | |
| Jul 21, 7:50 PM EDT | Special Weather Statement | BOX | Suffolk | 40 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.