Alert archive / New Hampshire / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 39, NWS Gray, ME

June 30, 2021Hillsborough County, Rockingham County, New Hampshire

NWS Gray, ME issued this severe thunderstorm warning at Jun 30, 2021, 5:12 PM EDT for Hillsborough County, Rockingham County, New Hampshire. It was in force for 33 min. 6 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, 5:12 PM EDT (21:12 UTC)
Expired
Jun 30, 2021, 5:45 PM EDT
In force
33 min
Issued by
NWS Gray, ME
Area
Storm-based polygon
Hail
1.25 in
Wind
60.0 mph

Counties Hillsborough County, NH, Rockingham County, NH

The radar

The Boston radar (KBOX), 94 km from the middle of the area, began a volume at 21:13 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, 5:14 PM EDTTSTM WND DMG2 W Nashua, NHMULTIPLE TREES DOWN ON BROAD STREET. TIME ESTIMATED FROM RADAR.
Jun 30, 5:15 PM EDTTSTM WND DMG2 Nw Nashua, NHCORRECTS TIME OF PREVIOUS TSTM WND DMG REPORT FROM 2 NW NASHUA. LARGE TREE LIMB DOWN ON LUTHERAN DRIVE. TIME ESTIMATED BY RADAR.
Jun 30, 5:20 PM EDTTSTM WND DMG2 Nnw Salem, NHMULTIPLE TREES DOWN. TIME ESTIMATED FROM RADAR.
Jun 30, 5:25 PM EDTTSTM WND DMGSalem, NHMULTIPLE TREES DOWN ALONG RTE. 111 BEFORE I-93.
Jun 30, 5:30 PM EDTTSTM WND DMG2 Wnw Atkinson, NHLARGE TREE FELL ON A HOUSE LEAVING IT UNINHABITABLE. TIME ESTIMATED BASED ON RADAR.
Jun 30, 5:45 PM EDTTSTM WND DMG2 N Dracut, MALARGE TREE DOWN ON LONGPOND DRIVE

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, 9.2 hours before the alert went out and 142 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.

833 
WUUS51 KGYX 302112
SVRGYX
NHC011-015-302200-
/O.NEW.KGYX.SV.W.0039.210630T2112Z-210630T2200Z/

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

The National Weather Service in Gray Maine has issued a

* Severe Thunderstorm Warning for...
  Southwestern Rockingham County in southern New Hampshire...
  Southeastern Hillsborough County in southern New Hampshire...

* Until 600 PM EDT.

* At 512 PM EDT, a severe thunderstorm was located over Nashua,
  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...
  Nashua, Derry, Merrimack, Salem, Amherst, Litchfield, Hollis,
  Hudson, Pelham, Seabrook, Londonderry, Hampstead, Atkinson,
  Kingston, Windham, Plaistow, Newton and South Hampton.

This includes the following highways...
 Interstate 93 between mile markers 0 and 11.
 Interstate 95 in New Hampshire near mile marker 0.

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 4270 7159 4285 7159 4289 7088 4288 7088
      4288 7093 4287 7097 4286 7103 4281 7107
      4282 7113 4281 7116 4279 7119 4274 7118
      4274 7125 4270 7129
TIME...MOT...LOC 2112Z 268DEG 26KT 4277 7148 

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

Ekster
2 follow-up statements
491 
WWUS51 KGYX 302129
SVSGYX

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

NHC011-302139-
/O.CAN.KGYX.SV.W.0039.000000T0000Z-210630T2200Z/
Hillsborough NH-
529 PM EDT Wed Jun 30 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN HILLSBOROUGH
COUNTY 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
southern New Hampshire.

LAT...LON 4274 7120 4287 7123 4288 7114 4289 7088
      4288 7088 4288 7093 4287 7097 4286 7103
      4281 7107 4282 7113 4281 7116 4279 7119
      4274 7118
TIME...MOT...LOC 2129Z 268DEG 26KT 4277 7131 

$$

NHC015-302200-
/O.CON.KGYX.SV.W.0039.000000T0000Z-210630T2200Z/
Rockingham NH-
529 PM EDT Wed Jun 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR SOUTH CENTRAL ROCKINGHAM COUNTY...

At 529 PM EDT, a severe thunderstorm was located over Pelham, or near
Salem, moving east at 30 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Derry, Salem, Seabrook, Hampstead, Atkinson, Kingston, Newton, South
Hampton and Plaistow.

This includes Interstate 95 in New Hampshire near mile marker 0.
 
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 4274 7120 4287 7123 4288 7114 4289 7088
      4288 7088 4288 7093 4287 7097 4286 7103
      4281 7107 4282 7113 4281 7116 4279 7119
      4274 7118
TIME...MOT...LOC 2129Z 268DEG 26KT 4277 7131 

HAIL...1.00IN
WIND...60MPH
 
$$
277 
WWUS51 KGYX 302145
SVSGYX

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

NHC015-302154-
/O.CAN.KGYX.SV.W.0039.000000T0000Z-210630T2200Z/
Rockingham NH-
545 PM EDT Wed Jun 30 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL ROCKINGHAM
COUNTY IS CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.  However heavy rain is
still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 700 PM EDT for
southern New Hampshire.

LAT...LON 4274 7120 4287 7123 4288 7114 4289 7088
      4288 7088 4288 7093 4287 7097 4286 7103
      4281 7107 4282 7113 4281 7116 4279 7119
      4274 7118
TIME...MOT...LOC 2143Z 268DEG 26KT 4277 7115 

$$

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, 4:11 PM EDTSevere Thunderstorm WarningGYXBelknap, Carroll, Merrimack, Strafford49 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

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.