Alert archive / New Hampshire / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 35, NWS Gray, ME

June 30, 20214 counties in New Hampshire

NWS Gray, ME issued this severe thunderstorm warning at Jun 30, 2021, 4:11 PM EDT for 4 counties in New Hampshire. It was in force for 49 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
Jun 30, 2021, 4:11 PM EDT (20:11 UTC)
Expired
Jun 30, 2021, 5:00 PM EDT
In force
49 min
Issued by
NWS Gray, ME
Area
Storm-based polygon
Hail
1.25 in
Wind
60.0 mph

Counties Belknap County, NH, Carroll County, NH, Merrimack County, NH, Strafford County, NH

The radar

The Portland,ME radar (KGYX), 92 km from the middle of the area, began a volume at 20:15 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
Jun 30, 4:15 PM EDTHAIL 1.251 S Gilmanton, NHHAIL UP TO HALF DOLLAR SIZE, WHICH LASTED FOR ABOUT 5 MINUTES. SOME BRANCHES ALSO CAME DOWN ACROSS HWY 140.
Jun 30, 4:53 PM EDTTSTM WND DMG4 Nne Barnstead, NHDEPUTY CHIEF OF BARNSTEAD FIRE REPORTS MULTIPLE INSTANCES OF STRUCTURAL DAMAGE AS A RESULT OF DOWN TREES. IN ADDITION, MULTIPLE HOUSES WERE STRUCK BY LIGHTNING AND A WATER RESCUE WAS PERFORMED ON A NEARBY LAKE. TIME ESTIMATED BY RADAR.

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
Jun 30, 12:06 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Gray, ME (KGYX), launched 12:00Z, 8.2 hours before the alert went out and 92 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, Gray, ME at 12:00Z on 2021-06-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 906 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, Gray, ME at 12:00Z on 2021-06-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 95 square meters per square second.19395878Sfc1 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
906 J/kg
Mixed-layer CIN
-60 J/kg
Mixed-layer LCL
1312 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
95 m²/s²
0-3 km storm-relative helicity
102 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.3

Open this sounding in Storm Lab

The text

As transmitted.

198 
WUUS51 KGYX 302011
SVRGYX
NHC001-003-013-017-302100-
/O.NEW.KGYX.SV.W.0035.210630T2011Z-210630T2100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Gray ME
411 PM EDT Wed Jun 30 2021

The National Weather Service in Gray Maine has issued a

* Severe Thunderstorm Warning for...
  Northwestern Strafford County in central New Hampshire...
  Southeastern Belknap County in central New Hampshire...
  East central Merrimack County in central New Hampshire...
  Southeastern Carroll County in northern New Hampshire...

* Until 500 PM EDT.

* At 411 PM EDT, a severe thunderstorm was located over Gilmanton, or
  8 miles south of Laconia, moving east at 30 mph.

  HAZARD...60 mph wind gusts and half dollar size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Rochester, Northwood, Barrington, Farmington, Lebanon, Loudon,
  Alton, Barnstead, Gilmanton, Canterbury, Belmont, Gilford,
  Chichester, Strafford, Pittsfield, New Durham, Middleton, Milton,
  Tilton and Northfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4326 7123 4327 7125 4328 7128 4332 7159
      4350 7153 4348 7097 4347 7096 4344 7096
      4342 7099 4340 7098 4339 7099 4336 7098
      4323 7103
TIME...MOT...LOC 2011Z 276DEG 27KT 4340 7145 

HAIL...1.25IN
WIND...60MPH
 
$$

ekster
2 follow-up statements
204 
WWUS51 KGYX 302027
SVSGYX

Severe Weather Statement
National Weather Service Gray ME
427 PM EDT Wed Jun 30 2021

NHC001-003-013-017-302100-
/O.CON.KGYX.SV.W.0035.000000T0000Z-210630T2100Z/
Strafford NH-Belknap NH-Merrimack NH-Carroll NH-
427 PM EDT Wed Jun 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM EDT
FOR CENTRAL STRAFFORD...SOUTHEASTERN BELKNAP...EAST CENTRAL MERRIMACK
AND SOUTHEASTERN CARROLL COUNTIES...

At 427 PM EDT, a severe thunderstorm was located near Alton, or 14
miles northwest of Rochester, moving east at 35 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Rochester, Barrington, Farmington, Lebanon, Alton, Barnstead,
Gilmanton, New Durham, Strafford, Middleton, Milton and Pittsfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4331 7133 4349 7131 4349 7122 4348 7097
      4347 7096 4344 7096 4342 7099 4340 7098
      4338 7099 4335 7098 4327 7102
TIME...MOT...LOC 2027Z 274DEG 31KT 4340 7122 

HAIL...1.25IN
WIND...60MPH
 
$$
364 
WWUS51 KGYX 302040
SVSGYX

Severe Weather Statement
National Weather Service Gray ME
440 PM EDT Wed Jun 30 2021

NHC003-013-302049-
/O.CAN.KGYX.SV.W.0035.000000T0000Z-210630T2100Z/
Merrimack NH-Carroll NH-
440 PM EDT Wed Jun 30 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL MERRIMACK AND
CARROLL COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 700 PM EDT for
southwestern Maine...and central New Hampshire.

LAT...LON 4336 7126 4348 7119 4348 7097 4347 7096
      4344 7096 4342 7099 4340 7098 4338 7099
      4335 7098 4333 7099
TIME...MOT...LOC 2039Z 276DEG 27KT 4339 7109 

$$

NHC001-017-302100-
/O.CON.KGYX.SV.W.0035.000000T0000Z-210630T2100Z/
Strafford NH-Belknap NH-
440 PM EDT Wed Jun 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM EDT
FOR NORTHWESTERN STRAFFORD AND SOUTHEASTERN BELKNAP COUNTIES...

At 439 PM EDT, a severe thunderstorm was located over Farmington, or
8 miles northwest of Rochester, moving east at 30 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Rochester, Farmington, Lebanon, Alton, Barnstead, New Durham,
Middleton and Milton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4336 7126 4348 7119 4348 7097 4347 7096
      4344 7096 4342 7099 4340 7098 4338 7099
      4335 7098 4333 7099
TIME...MOT...LOC 2039Z 276DEG 27KT 4339 7109 

HAIL...1.25IN
WIND...60MPH
 
$$

The office that day

Everything else NWS Gray, ME issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 30, 2:39 PM EDTSpecial Weather StatementGYXGrafton36 min
Jun 30, 3:02 PM EDTSevere Thunderstorm WarningGYXGrafton, Sullivan43 min
Jun 30, 3:10 PM EDTSevere Thunderstorm WarningGYXCarroll, Coos, Grafton17 min
Jun 30, 3:42 PM EDTSpecial Weather StatementGYXBelknap48 min
Jun 30, 3:43 PM EDTSpecial Weather StatementGYXCheshire47 min
Jun 30, 4:01 PM EDTSevere Thunderstorm WarningGYXBelknap, Carroll, Grafton, Merrimack, Strafford27 min
Jun 30, 4:05 PM EDTSevere Thunderstorm WarningGYXCheshire, Sullivan35 min
Jun 30, 4:25 PM EDTSevere Thunderstorm WarningGYXCheshire, Hillsborough50 min
Jun 30, 4:44 PM EDTSpecial Weather StatementGYXMerrimack46 min
Jun 30, 4:53 PM EDTSpecial Weather StatementGYXRockingham37 min
Jun 30, 4:58 PM EDTSevere Thunderstorm WarningGYXRockingham32 min
Jun 30, 5:12 PM EDTSevere Thunderstorm WarningGYXHillsborough, Rockingham33 min

Nearby

Severe Thunderstorm Warnings in New Hampshire, 2021Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.