Alert archive / New Hampshire / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 93, NWS Gray, ME

September 15, 20215 counties in New Hampshire; Cumberland County, Oxford County, Maine

NWS Gray, ME issued this severe thunderstorm warning at Sep 15, 2021, 4:09 PM EDT for 5 counties in New Hampshire; Cumberland County, Oxford County, Maine. It was in force for 51 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: Sep 15, 2021, 4:09 PM EDT (20:09 UTC)
Expired: Sep 15, 2021, 5:00 PM EDT
In force: 51 min
Issued by: NWS Gray, ME
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Cumberland County, ME, Oxford County, ME, Belknap County, NH, Carroll County, NH, Coos County, NH, Grafton County, NH, Merrimack County, NH

The radar

The Portland,ME radar (KGYX), 79 km from the middle of the area, began a volume at 20:11 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 15, 4:18 PM EDT	HAIL 1	1 N North Sandwich, NH
Sep 15, 4:42 PM EDT	TSTM WND DMG	2 Ne Waterford, ME	LARGE 100 FOOT TALL PINE TREE CAME DOWN IN A SPOTTERS YARD WHICH HIT THEIR ROOF AND CRUSHED 2 CARS. TIME ESTIMATED BASED ON RADAR.
Sep 15, 4:48 PM EDT	TSTM WND DMG	1 E Norway, ME	2 TREES DOWN 1/2 MILE EAST OF DOWNTOWN NORWAY. 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.

Issued	Product	Office	Lasted
Sep 15, 1:15 PM EDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Gray, ME (KGYX), launched 12:00Z, 8.2 hours before the alert went out and 78 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: 101 J/kg
Mixed-layer CIN: -167 J/kg
Mixed-layer LCL: 468 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 299 m²/s²
0-3 km storm-relative helicity: 318 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

As transmitted.

081 
WUUS51 KGYX 152009
SVRGYX
MEC005-017-NHC001-003-007-009-013-152100-
/O.NEW.KGYX.SV.W.0093.210915T2009Z-210915T2100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Gray ME
409 PM EDT Wed Sep 15 2021

The National Weather Service in Gray Maine has issued a

* Severe Thunderstorm Warning for...
  Southwestern Oxford County in western Maine...
  Northwestern Cumberland County in southwestern Maine...
  Southeastern Coos County in northern New Hampshire...
  Southeastern Grafton County in northern New Hampshire...
  Northwestern Belknap County in central New Hampshire...
  Northwestern Merrimack County in central New Hampshire...
  Carroll County in northern New Hampshire...

* Until 500 PM EDT.

* At 409 PM EDT, severe thunderstorms were located along a line
  extending from near Bethel to near Conway to near Moultonborough to
  near Franklin, moving east at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Laconia, Conway, Franklin, Bridgton, Fryeburg, Bethel,
  Moultonborough, Ossipee, Naples, Meredith, Holderness, Ashland,
  Hiram, Effingham, Cornish, Danbury, Waterford, Tamworth, Sandwich
  and Wolfeboro.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in Gray Maine.

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

&&

LAT...LON 4352 7194 4377 7158 4396 7154 4415 7117
      4433 7115 4449 7053 4405 7052 4390 7059
      4381 7080 4379 7099 4372 7098 4347 7159
      4346 7200
TIME...MOT...LOC 2009Z 255DEG 33KT 4448 7080 4393 7107 4378 7130 4351
7172

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Legro

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 15, 7:50 AM EDT	Special Weather Statement	GYX	Coos	55 min
Sep 15, 2:18 PM EDT	Severe Thunderstorm Warning	GYX	Coos, Grafton	57 min
Sep 15, 2:31 PM EDT	Severe Thunderstorm Warning	GYX	Belknap, Carroll, Coos, Grafton, Merrimack, Sullivan	59 min
Sep 15, 2:33 PM EDT	Severe Thunderstorm Warning	GYX	Coos	42 min
Sep 15, 3:04 PM EDT	Severe Thunderstorm Warning	GYX	Belknap, Grafton, Merrimack, Sullivan	56 min
Sep 15, 3:22 PM EDT	Severe Thunderstorm Warning	GYX	Belknap, Carroll, Coos, Grafton, Merrimack, Sullivan	53 min
Sep 15, 4:07 PM EDT	Severe Thunderstorm Warning	GYX	Cheshire, Hillsborough, Merrimack, Sullivan	38 min
Sep 15, 4:44 PM EDT	Severe Thunderstorm Warning	GYX	Belknap, Carroll, Merrimack, Strafford	46 min
Sep 15, 5:09 PM EDT	Severe Thunderstorm Warning	GYX	Cheshire, Hillsborough, Merrimack	51 min
Sep 15, 5:29 PM EDT	Severe Thunderstorm Warning	GYX	Carroll, Strafford	61 min
Sep 15, 2:33 AM EDT	Small Craft Advisory	GYX		19 hr
Sep 15, 6:56 AM EDT	Special Weather Statement	GYX	Franklin	64 min
Sep 15, 7:53 AM EDT	Special Weather Statement	GYX	Franklin	52 min
Sep 15, 9:00 AM EDT	Special Weather Statement	GYX	Franklin	45 min
Sep 15, 3:04 PM EDT	Severe Thunderstorm Warning	GYX	Franklin, Oxford	41 min
Sep 15, 3:41 PM EDT	Severe Thunderstorm Warning	GYX	Franklin, Oxford, Somerset	49 min
Sep 15, 4:28 PM EDT	Tornado Warning	GYX	Cumberland, Oxford	32 min
Sep 15, 4:58 PM EDT	Severe Thunderstorm Warning	GYX	Somerset	29 min
Sep 15, 5:14 PM EDT	Severe Thunderstorm Warning	GYX	Androscoggin, Cumberland, Kennebec, Oxford, Sagadahoc	46 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.