Alert archive / New Hampshire / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 115, NWS Boston/Norton, MA

September 18, 2012Cheshire County, Hillsborough County, New Hampshire

NWS Boston/Norton, MA issued this severe thunderstorm warning at Sep 18, 2012, 9:31 PM EDT for Cheshire County, Hillsborough County, New Hampshire. It was in force for 59 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 18, 2012, 9:31 PM EDT (01:31 UTC)
Expired
Sep 18, 2012, 10:30 PM EDT
In force
59 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon

Counties Cheshire County, NH, Hillsborough County, NH

The radar

The Boston radar (KBOX), 142 km from the middle of the area, began a volume at 01:31 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

TimeReportWhereRemark
Sep 18, 9:32 PM EDTTSTM WND DMGWinchester, NHTREE DOWN ON RTE 10 NEAR SEMINARY ROAD
Sep 18, 9:34 PM EDTTSTM WND DMGHarrisville, NHTREE AND WIRES DOWN ON CHURCH STREET

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Sep 18, 7:54 PM EDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Albany, NY (KALY), launched 00:00Z, 1.5 hours before the alert went out and 155 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-pSkew-T log-p diagram, Albany, NY at 00:00Z on 2012-09-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 47 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Albany, NY at 00:00Z on 2012-09-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -4 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
47 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
675 m above ground
0-6 km bulk shear
67 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
47 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

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

770 
WUUS51 KBOX 190131
SVRBOX
NHC005-011-190230-
/O.NEW.KBOX.SV.W.0115.120919T0131Z-120919T0230Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
931 PM EDT TUE SEP 18 2012

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN CHESHIRE COUNTY IN SOUTHERN NEW HAMPSHIRE...
  THIS INCLUDES THE CITIES OF...KEENE...JAFFREY...
  WESTERN HILLSBOROUGH COUNTY IN SOUTHERN NEW HAMPSHIRE...

* UNTIL 1030 PM EDT

* AT 929 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
  A LINE OF SHOWERS AND THUNDERSTORMS CAPABLE OF PRODUCING WINDS 
  IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE FROM  
  MARLOW TO WINCHESTER...AND WAS MOVING NORTHEAST AT 50 MPH.

* SOME LOCATIONS IN THE WARNING INCLUDE...
  KEENE...JAFFREY...ANTRIM...PETERBOROUGH.

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...AS WELL AS DEADLY 
LIGHTNING AND TORRENTIAL RAIN. GET TO SAFE SHELTER NOW...INSIDE A 
STURDY BUILDING OR IN A VEHICLE. DO NOT SEEK SHELTER UNDER TREES. 

IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY 
LIGHTNING. DRIVERS SHOULD BE ALERT FOR PONDING OF WATER AND AVOID 
FLOODED ROADS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 300 AM EDT
WEDNESDAY MORNING FOR NORTHERN CONNECTICUT AND MASSACHUSETTS AND
SOUTHERN NEW HAMPSHIRE AND CENTRAL RHODE ISLAND.

&&

LAT...LON 4312 7185 4315 7169 4315 7166 4306 7163
      4272 7186 4275 7236 4277 7239 4317 7226
      4319 7217 4314 7217 4313 7205 4315 7203
      4318 7203 4321 7191
TIME...MOT...LOC 0129Z 218DEG 49KT 4326 7212 4285 7226
          4250 7258

$$

WTB
1 follow-up statement
182 
WWUS51 KBOX 190159
SVSBOX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
959 PM EDT TUE SEP 18 2012

NHC005-011-190230-
/O.CON.KBOX.SV.W.0115.000000T0000Z-120919T0230Z/
CHESHIRE NH-HILLSBOROUGH NH-
959 PM EDT TUE SEP 18 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM EDT
FOR WESTERN HILLSBOROUGH AND EASTERN CHESHIRE COUNTIES...

AT 954 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A LINE OF SHOWERS AND THUNDERSTORMS CAPABLE OF PRODUCING 
DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG 
A LINE EXTENDING FROM HILLSBOROUGH TO WINCHESTER...AND WERE MOVING 
NORTHEAST AT 50 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO 
RINDGE...JAFFREY...PETERBOROUGH...AND ANTRIM.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 300 AM EDT
WEDNESDAY MORNING FOR NORTHERN CONNECTICUT AND MASSACHUSETTS AND
SOUTHERN NEW HAMPSHIRE AND CENTRAL RHODE ISLAND.

&&

LAT...LON 4312 7185 4315 7169 4315 7166 4306 7163
      4272 7186 4275 7236 4277 7239 4317 7226
      4319 7217 4314 7217 4313 7205 4315 7203
      4318 7203 4321 7191
TIME...MOT...LOC 0157Z 218DEG 49KT 4356 7179 4315 7193
          4280 7226

$$

WTB

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 18, 8:34 PM EDTSevere Thunderstorm WarningBOXCheshire, Hillsborough56 min
Sep 18, 8:52 PM EDTAreal Flood AdvisoryBOXCheshire, Hillsborough5 hr
Sep 18, 10:16 PM EDTSevere Thunderstorm WarningBOXHillsborough59 min
Sep 18, 11:16 PM EDTSevere Thunderstorm WarningBOXHillsborough59 min
Sep 19, 3:41 AM EDTFrost AdvisoryBOXCheshire28 hr

Nearby

Severe Thunderstorm Warnings in New Hampshire, 2012Every 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.