Alert archive / New Hampshire / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 103, NWS Boston/Norton, MA

September 8, 2012Cheshire County, Hillsborough County, New Hampshire

NWS Boston/Norton, MA issued this severe thunderstorm warning at Sep 8, 2012, 4:30 PM EDT for Cheshire County, Hillsborough County, New Hampshire. It was in force for 45 min. 2 reports 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: Sep 8, 2012, 4:30 PM EDT (20:30 UTC)
Expired: Sep 8, 2012, 5:15 PM EDT
In force: 45 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon

Counties Cheshire County, NH, Hillsborough County, NH

The radar

The Boston radar (KBOX), 139 km from the middle of the area, began a volume at 20:31 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 was reported inside it

Time	Report	Where	Remark
Sep 8, 4:40 PM EDT	TSTM WND DMG	Troy, NH	TREE AND WIRES DOWN ON COLONIAL DRIVE
Sep 8, 4:45 PM EDT	TSTM WND DMG	Harrisville, NH	TREE AND WIRES DOWN ON HANCOCK ROAD

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, 8.5 hours before the alert went out and 159 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1021 J/kg
Mixed-layer CIN: -20 J/kg
Mixed-layer LCL: 466 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 176 m²/s²
0-3 km storm-relative helicity: 216 m²/s²
Significant tornado parameter: 0.9
Supercell composite: 7.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

660 
WUUS51 KBOX 082030
SVRBOX
NHC005-011-082115-
/O.NEW.KBOX.SV.W.0103.120908T2030Z-120908T2115Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
430 PM EDT SAT SEP 8 2012

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EAST CENTRAL CHESHIRE COUNTY IN SOUTHERN NEW HAMPSHIRE...
  NORTHWESTERN HILLSBOROUGH COUNTY IN SOUTHERN NEW HAMPSHIRE...

* UNTIL 515 PM EDT

* AT 427 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH.  THIS STORM WAS LOCATED NEAR FITZWILLIAM...OR NEAR
  JAFFREY...AND WAS MOVING NORTHEAST AT 50 MPH.

* SOME LOCATIONS IN THE WARNING INCLUDE...DUBLIN...HARRISVILLE...
  HANCOCK...BENNINGTON...WINDSOR...DEERING...HILLSBOROUGH AND WEARE.

DOPPLER RADAR INDICATED WEAK ROTATION WITHIN THIS STORM. WHILE NOT
IMMEDIATELY LIKELY...A TORNADO MAY DEVELOP. REMAIN CALM...BUT TAKE
COVER NOW. GO TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A STURDY
BUILDING. AVOID WINDOWS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 900 PM EDT SATURDAY EVENING
FOR NORTHERN CONNECTICUT AND WESTERN MASSACHUSETTS.

&&

LAT...LON 4314 7187 4312 7185 4315 7167 4314 7166
      4312 7166 4275 7213 4280 7221 4321 7195
      4321 7190
TIME...MOT...LOC 2030Z 214DEG 42KT 4284 7211

$$

NOCERA

The office that day

Everything else NWS Boston/Norton, MA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 8, 4:09 PM EDT	Special Weather Statement	BOX	Cheshire	51 min
Sep 8, 5:32 PM EDT	Severe Thunderstorm Warning	BOX	Hillsborough	36 min
Sep 8, 5:45 PM EDT	Severe Thunderstorm Warning	BOX	Cheshire, Hillsborough	60 min
Sep 8, 6:31 PM EDT	Severe Thunderstorm Warning	BOX	Cheshire, Hillsborough	59 min
Sep 8, 6:58 PM EDT	Severe Thunderstorm Warning	BOX	Cheshire, Hillsborough	32 min
Sep 8, 7:30 PM EDT	Severe Thunderstorm Warning	BOX	Cheshire, Hillsborough	60 min

Nearby

Severe Thunderstorm Warnings in New Hampshire, 2012 Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.