Alert archive / New Hampshire / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 315
The Storm Prediction Center issued this severe thunderstorm watch at May 29, 2012, 3:44 PM EDT for 8 counties in New Hampshire. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- May 29, 2012, 3:44 PM EDT (19:44 UTC)
- Expired
- May 29, 2012, 8:58 PM EDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
Counties Belknap County, NH, Carroll County, NH, Cheshire County, NH, Coos County, NH, Grafton County, NH, Hillsborough County, NH, Merrimack County, NH, Sullivan County, NH
The radar
The Portland,ME radar (KGYX), 114 km from the middle of the area, began a volume at 19:47 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 29, 3:51 PM EDT | Severe Thunderstorm Warning | BOX | Cheshire, Hillsborough | 54 min |
| May 29, 3:56 PM EDT | Severe Thunderstorm Warning | GYX | Merrimack, Sullivan | 49 min |
| May 29, 4:37 PM EDT | Tornado Warning | BOX | Cheshire | 38 min |
| May 29, 4:39 PM EDT | Flash Flood Warning | GYX | Coos | 6 hr |
| May 29, 4:45 PM EDT | Flash Flood Warning | BOX | Cheshire | 3 hr |
| May 29, 4:49 PM EDT | Severe Thunderstorm Warning | GYX | Grafton, Merrimack, Sullivan | 20 min |
| May 29, 4:50 PM EDT | Severe Thunderstorm Warning | GYX | Belknap, Carroll, Grafton, Merrimack | 55 min |
| May 29, 4:51 PM EDT | Flash Flood Warning | GYX | Carroll, Coos, Grafton | 6 hr |
| May 29, 5:09 PM EDT | Severe Thunderstorm Warning | BOX | Cheshire, Hillsborough | 66 min |
| May 29, 6:13 PM EDT | Severe Thunderstorm Warning | BOX | Cheshire, Hillsborough | 62 min |
| May 29, 6:39 PM EDT | Severe Thunderstorm Warning | BOX | Cheshire | 66 min |
| May 29, 7:09 PM EDT | Severe Thunderstorm Warning | BOX | Cheshire, Hillsborough | 25 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, 7.7 hours before the alert went out and 114 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
- 3 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 426 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km storm-relative helicity
- 305 m²/s²
- 0-3 km storm-relative helicity
- 388 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.8
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 29, 2:49 PM EDT | Mesoscale Discussion | SPC | Belknap, Carroll, Coos, Grafton, Merrimack | 56 min |
| May 29, 7:01 PM EDT | Mesoscale Discussion | SPC | Hillsborough | 89 min |
| May 29, 11:43 AM EDT | Mesoscale Discussion | SPC | Rutland | 62 min |
| May 29, 12:01 PM EDT | Mesoscale Discussion | SPC | Addison, Bennington, Rutland, Windham, Windsor | 59 min |
| May 29, 12:26 PM EDT | Tornado Watch | SPC | Addison, Bennington, Caledonia, Chittenden, Essex, Franklin and 8 more | 8 hr |
| May 29, 1:52 PM EDT | Mesoscale Discussion | SPC | Addison, Bennington, Caledonia, Chittenden, Essex, Franklin and 8 more | 53 min |
| May 29, 3:26 PM EDT | Mesoscale Discussion | SPC | Addison, Bennington, Caledonia, Chittenden, Essex, Franklin and 8 more | 64 min |
Nearby
Severe Thunderstorm Watches in New Hampshire, 2012Every severe thunderstorm watch in 2012
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.