Alert archive / Maine / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 46, NWS Gray, ME

July 20, 2021Cumberland County, Maine

NWS Gray, ME issued this severe thunderstorm warning at Jul 20, 2021, 2:46 PM EDT for Cumberland County, Maine. It was in force for 44 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
Jul 20, 2021, 2:46 PM EDT (18:46 UTC)
Expired
Jul 20, 2021, 3:30 PM EDT
In force
44 min
Issued by
NWS Gray, ME
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Cumberland County, ME

The radar

The Portland,ME radar (KGYX), 24 km from the middle of the area, began a volume at 18:46 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
Jul 20, 2:55 PM EDTTSTM WND DMG2 Nnw Portland, METREE LIMBS DOWN NEAR WASHINGTON AND ALLEN AVE IN PORTLAND.
Jul 20, 3:10 PM EDTTSTM WND DMGFalmouth, MEMULTIPLE TREES DOWN, SOME ON WIRES. PAYSON RD.

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, 6.8 hours before the alert went out and 24 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 2021-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 205 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 2021-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 square meters per square second.1939Sfc1 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
205 J/kg
Mixed-layer CIN
-63 J/kg
Mixed-layer LCL
1050 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

440 
WUUS51 KGYX 201846
SVRGYX
MEC005-201930-
/O.NEW.KGYX.SV.W.0046.210720T1846Z-210720T1930Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Gray ME
246 PM EDT Tue Jul 20 2021

The National Weather Service in Gray Maine has issued a

* Severe Thunderstorm Warning for...
  Southeastern Cumberland County in southwestern Maine...

* Until 330 PM EDT.

* At 245 PM EDT, a severe thunderstorm was located over Falmouth, or
  just north of Portland, moving east at 15 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...
  Portland, South Portland, Westbrook, Cumberland, Falmouth, Cape
  Elizabeth, Yarmouth, Harpswell and Chebeague Island.

This includes the following highways...
 Interstate 295 between mile markers 4 and 14.
 Interstate 95 between mile markers 49 and 53.

This also includes...
  Peaks Island, Long Island, Cushing Island, Cousins Island, and
Bailey Island.
 
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 4365 7031 4369 7034 4375 7030 4378 7021
      4380 6996 4363 7000 4362 7005 4359 7008
TIME...MOT...LOC 1845Z 275DEG 15KT 4372 7027 

HAIL...1.00IN
WIND...60MPH
 
$$

Kimble
1 follow-up statement
603 
WWUS51 KGYX 201914
SVSGYX

Severe Weather Statement
National Weather Service Gray ME
314 PM EDT Tue Jul 20 2021

MEC005-201930-
/O.CON.KGYX.SV.W.0046.000000T0000Z-210720T1930Z/
Cumberland ME-
314 PM EDT Tue Jul 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM EDT
FOR SOUTHEASTERN CUMBERLAND COUNTY...

At 312 PM EDT, a severe thunderstorm was located near Falmouth 
Foreside, moving east at 10 mph into Casco Bay. Damaging winds and 
torrential rainfall are likely.

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...
Portland, South Portland, Cumberland, Falmouth, Harpswell and
Chebeague Island.

This also includes...
  Peaks Island, Long Island, Cushing Island, Great Diamond Island,
and Mackworth Island.
 
This includes Interstate 295 between mile markers 6 and 12.
 
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 4364 7023 4368 7028 4374 7026 4375 7020
      4374 7000 4363 7006 4360 7012
TIME...MOT...LOC 1912Z 290DEG 9KT 4369 7021 

HAIL...1.00IN
WIND...60MPH
 
$$

Kimble

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 2:08 PM EDTSpecial Weather StatementGYXAndroscoggin, Cumberland82 min
Jul 20, 2:46 PM EDTSpecial Marine WarningGYX59 min
Jul 20, 3:44 PM EDTSpecial Weather StatementGYXYork16 min
Jul 20, 4:00 PM EDTSpecial Marine WarningGYX32 min

Nearby

Severe Thunderstorm Warnings in Maine, 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.