Alert archive / New Hampshire / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 80, NWS Gray, ME

July 27, 2021Rockingham County, Strafford County, New Hampshire; York County, Maine

NWS Gray, ME issued this severe thunderstorm warning at Jul 27, 2021, 6:36 PM EDT for Rockingham County, Strafford County, New Hampshire; York County, Maine. It was in force for 39 min. 3 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: Jul 27, 2021, 6:36 PM EDT (22:36 UTC)
Expired: Jul 27, 2021, 7:15 PM EDT
In force: 39 min
Issued by: NWS Gray, ME
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties York County, ME, Rockingham County, NH, Strafford County, NH

The radar

The Portland,ME radar (KGYX), 101 km from the middle of the area, began a volume at 22:37 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
Jul 27, 6:40 PM EDT	TSTM WND DMG	1 Sse Lee, NH	TREE DOWN ON TUDDLE ROAD. TIME ESTIMATED FROM RADAR.
Jul 27, 6:44 PM EDT	TSTM WND DMG	3 Sw Lee, NH	TREE DOWN ON HARVEY MILL ROAD. TIME ESTIMATED FROM RADAR.
Jul 27, 6:45 PM EDT	TSTM WND DMG	Newmarket, NH	TREES AND POWER LINES DOWN.

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, 10.6 hours before the alert went out and 100 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: 1 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1443 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 11 m²/s²
0-3 km storm-relative helicity: 24 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

The text

As transmitted.

324 
WUUS51 KGYX 272236
SVRGYX
MEC031-NHC015-017-272315-
/O.NEW.KGYX.SV.W.0080.210727T2236Z-210727T2315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Gray ME
636 PM EDT Tue Jul 27 2021

The National Weather Service in Gray Maine has issued a

* Severe Thunderstorm Warning for...
  South central York County in southwestern Maine...
  Northeastern Rockingham County in southern New Hampshire...
  Southeastern Strafford County in central New Hampshire...

* Until 715 PM EDT.

* At 636 PM EDT, severe thunderstorms were located along a line
  extending from near Northwood to near York, moving east at 30 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Portsmouth, Durham, Exeter, Kittery, Dover, Barrington, Epping,
  Brentwood, Greenland, York, Newington, Stratham, Newmarket, Rye,
  South Berwick, Eliot, Lee, Fremont, Madbury and Nottingham.

This includes the following highways...
 Interstate 95 between mile markers 1 and 11.
 Interstate 95 in New Hampshire between mile markers 10 and 16.

This also includes...
  York Beach.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4300 7109 4318 7112 4323 7056 4313 7057
      4303 7066
TIME...MOT...LOC 2236Z 262DEG 26KT 4314 7111 4318 7073 

TORNADO...POSSIBLE
HAIL...0.75IN
WIND...60MPH
 
$$

Ekster

1 follow-up statement

310 
WWUS51 KGYX 272307
SVSGYX

Severe Weather Statement
National Weather Service Gray ME
707 PM EDT Tue Jul 27 2021

MEC031-NHC015-017-272317-
/O.EXP.KGYX.SV.W.0080.000000T0000Z-210727T2315Z/
York ME-Rockingham NH-Strafford NH-
707 PM EDT Tue Jul 27 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL YORK...
NORTHEASTERN ROCKINGHAM AND SOUTHEASTERN STRAFFORD COUNTIES WILL
EXPIRE AT 715 PM EDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.  However heavy rain
is still possible with these thunderstorms.

LAT...LON 4300 7109 4318 7112 4323 7056 4313 7057
      4303 7066
TIME...MOT...LOC 2307Z 262DEG 26KT 4317 7082 4321 7044 

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 27, 4:30 PM EDT	Severe Thunderstorm Warning	GYX	Cheshire, Sullivan	45 min
Jul 27, 5:13 PM EDT	Special Weather Statement	GYX	Cheshire	32 min
Jul 27, 5:38 PM EDT	Special Weather Statement	GYX	Strafford	37 min
Jul 27, 6:00 PM EDT	Special Weather Statement	GYX	Rockingham	30 min
Jul 27, 6:16 PM EDT	Special Weather Statement	GYX	Strafford	29 min
Jul 27, 6:30 PM EDT	Special Weather Statement	GYX	Rockingham	30 min
Jul 27, 6:54 PM EDT	Areal Flood Advisory	GYX	Rockingham, Strafford	111 min
Jul 27, 6:45 PM EDT	Special Marine Warning	GYX		60 min

Nearby

Severe Thunderstorm Warnings in New Hampshire, 2021 Severe Thunderstorm Warnings in Maine, 2021 Every 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.