Alert archive / Massachusetts / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 687
The Storm Prediction Center issued this severe thunderstorm watch at Jul 26, 2011, 2:30 PM EDT for 5 states. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 26, 2011, 2:30 PM EDT (18:30 UTC)
- Expired
- Jul 26, 2011, 10:00 PM EDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 34 counties
Capitol Planning Region, CT, Greater Bridgeport Planning Region, CT, Lower Connecticut River Valley Planning Region, CT, Naugatuck Valley Planning Region, CT, Northeastern Connecticut Planning Region, CT, Southeastern Connecticut Planning Region, CT, Bristol County, MA, Essex County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Norfolk County, MA, Plymouth County, MA, Suffolk County, MA, Worcester County, MA, Androscoggin County, ME, Cumberland County, ME, Franklin County, ME, Kennebec County, ME, Oxford County, ME, Somerset County, ME, York County, ME, Belknap County, NH, Carroll County, NH, Cheshire County, NH, Hillsborough County, NH, Merrimack County, NH, Rockingham County, NH, Strafford County, NH, Orange County, NY, Putnam County, NY, Rockland County, NY, Westchester County, NY
The radar
The Portland,ME radar (KGYX), 79 km from the middle of the area, began a volume at 18:31 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 SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 10%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 60%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
20 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 26, 3:13 PM EDT | Severe Thunderstorm Warning | BOX | Franklin, Hampden, Hampshire | 62 min |
| Jul 26, 3:14 PM EDT | Severe Thunderstorm Warning | GYX | York | 17 min |
| Jul 26, 4:09 PM EDT | Severe Thunderstorm Warning | BOX | Capitol Planning Region | 66 min |
| Jul 26, 4:10 PM EDT | Severe Thunderstorm Warning | GYX | Grafton, Merrimack, Sullivan | 50 min |
| Jul 26, 4:15 PM EDT | Severe Thunderstorm Warning | BOX | Hampden, Hampshire | 60 min |
| Jul 26, 4:28 PM EDT | Tornado Warning | BOX | Hampden, Hampshire | 47 min |
| Jul 26, 4:51 PM EDT | Tornado Warning | BOX | Northeastern Connecticut Planning Region | 39 min |
| Jul 26, 4:52 PM EDT | Severe Thunderstorm Warning | BOX | Capitol Planning Region | 53 min |
| Jul 26, 4:58 PM EDT | Severe Thunderstorm Warning | GYX | Belknap, Merrimack | 32 min |
| Jul 26, 5:06 PM EDT | Severe Thunderstorm Warning | BOX | Northeastern Connecticut Planning Region | 39 min |
| Jul 26, 5:17 PM EDT | Severe Thunderstorm Warning | OKX | Lower Connecticut River Valley Planning Region, Southeastern Connecticut Planning Region | 43 min |
| Jul 26, 5:22 PM EDT | Severe Thunderstorm Warning | GYX | Belknap, Carroll, Strafford | 38 min |
| Jul 26, 5:24 PM EDT | Severe Thunderstorm Warning | OKX | Lower Connecticut River Valley Planning Region, Naugatuck Valley Planning Region | 40 min |
| Jul 26, 5:24 PM EDT | Flash Flood Warning | GYX | Belknap, Carroll, Strafford | 3 hr |
| Jul 26, 5:30 PM EDT | Severe Thunderstorm Warning | BOX | Northeastern Connecticut Planning Region | 45 min |
| Jul 26, 5:38 PM EDT | Severe Thunderstorm Warning | OKX | Greater Bridgeport Planning Region | 52 min |
| Jul 26, 5:39 PM EDT | Severe Thunderstorm Warning | GYX | York | 36 min |
| Jul 26, 6:17 PM EDT | Severe Thunderstorm Warning | GYX | York | 43 min |
| Jul 26, 6:44 PM EDT | Severe Thunderstorm Warning | GYX | Franklin, Oxford, Somerset | 33 min |
| Jul 26, 7:19 PM EDT | Severe Thunderstorm Warning | GYX | Androscoggin, Franklin, Kennebec, Oxford, Somerset | 56 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Gray, ME (KGYX), launched 12:00Z, 6.5 hours before the alert went out and 79 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
- 28 J/kg
- Mixed-layer CIN
- -21 J/kg
- Mixed-layer LCL
- 487 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 162 m²/s²
- 0-3 km storm-relative helicity
- 180 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 26, 11:05 AM EDT | Mesoscale Discussion | SPC | 55 min | |
| Jul 26, 11:28 AM EDT | Severe Thunderstorm Watch | SPC | Northwest Hills Planning Region | 8 hr |
| Jul 26, 1:34 PM EDT | Mesoscale Discussion | SPC | 86 min | |
| Jul 26, 6:17 PM EDT | Mesoscale Discussion | SPC | 58 min | |
| Jul 26, 3:39 PM EDT | Mesoscale Discussion | SPC | Berkshire | 66 min |
| Jul 26, 5:24 PM EDT | Mesoscale Discussion | SPC | Bronx, Kings, Nassau, New York, Queens, Richmond and 2 more | 66 min |
Nearby
Severe Thunderstorm Watches in Massachusetts, 2011Severe Thunderstorm Watches in Connecticut, 2011Severe Thunderstorm Watches in Maine, 2011Every severe thunderstorm watch in 2011
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.