Alert archive / Michigan / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 77, NWS Gaylord, MI

August 21, 2011Alpena County, Presque Isle County, Michigan

NWS Gaylord, MI issued this severe thunderstorm warning at Aug 21, 2011, 4:10 PM EDT for Alpena County, Presque Isle County, Michigan. It was in force for 38 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 21, 2011, 4:10 PM EDT (20:10 UTC)
Expired
Aug 21, 2011, 4:48 PM EDT
In force
38 min
Issued by
NWS Gaylord, MI
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Alpena County, MI, Presque Isle County, MI

The radar

The NCL Michigan radar (KAPX), 107 km from the middle of the area, began a volume at 20:13 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.

The nearest sounding before it

Alpena, MI (KAPX), launched 12:00Z, 8.2 hours before the alert went out and 77 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, Alpena, MI at 12:00Z on 2011-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 76 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, Alpena, MI at 12:00Z on 2011-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 7 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
76 J/kg
Mixed-layer CIN
-25 J/kg
Mixed-layer LCL
1325 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
7 m²/s²
0-3 km storm-relative helicity
76 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

688 
WUUS53 KAPX 212010
SVRAPX
MIC007-141-212100-
/O.NEW.KAPX.SV.W.0077.110821T2010Z-110821T2100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GAYLORD MI
410 PM EDT SUN AUG 21 2011

THE NATIONAL WEATHER SERVICE IN GAYLORD HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN ALPENA COUNTY IN NORTHERN LOWER MICHIGAN...
  SOUTHEASTERN PRESQUE ISLE COUNTY IN NORTHERN LOWER MICHIGAN...

* UNTIL 500 PM EDT

* AT 410 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  ALPENA...AND MOVING SOUTHEAST AT 30 MPH.

* LOCATIONS IMPACTED INCLUDE...
  OSSINEKE AND DEVILS LAKE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR
YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 4501 8327 4507 8339 4505 8343 4499 8340
      4498 8344 4494 8343 4491 8332 4486 8354
      4517 8379 4533 8349 4526 8337 4524 8340
      4519 8336 4519 8331 4519 8335 4503 8326
      4506 8324 4504 8318 4503 8318
TIME...MOT...LOC 2010Z 312DEG 27KT 4510 8341
WIND...HAIL 60MPH 1.00IN

$$
2 follow-up statements
472 
WWUS34 KAPX 212032
SVSAPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE GAYLORD MI
432 PM EDT SUN AUG 21 2011

MIC141-212042-
/O.CAN.KAPX.SV.W.0077.000000T0000Z-110821T2100Z/
PRESQUE ISLE MI-
432 PM EDT SUN AUG 21 2011

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN PRESQUE ISLE
COUNTY IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED 
AREA.

LAT...LON 4501 8327 4507 8339 4505 8343 4494 8343
      4490 8337 4486 8354 4499 8364 4516 8334
      4509 8330 4508 8331 4506 8330 4505 8328
      4503 8325 4502 8325
TIME...MOT...LOC 2032Z 312DEG 27KT 4499 8324
WIND...HAIL <50MPH <.50IN

$$

MIC007-212100-
/O.CON.KAPX.SV.W.0077.000000T0000Z-110821T2100Z/
ALPENA MI-
432 PM EDT SUN AUG 21 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHEASTERN
ALPENA COUNTY UNTIL 500 PM EDT...

AT 427 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 9 MILES
SOUTHEAST OF ALPENA...MOVING SOUTHEAST AT 30 MPH.

LOCATIONS IMPACTED INCLUDE...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR
YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 4501 8327 4507 8339 4505 8343 4494 8343
      4490 8337 4486 8354 4499 8364 4516 8334
      4509 8330 4508 8331 4506 8330 4505 8328
      4503 8325 4502 8325
TIME...MOT...LOC 2032Z 312DEG 27KT 4499 8324
WIND...HAIL 60MPH 1.00IN

$$
040 
WWUS34 KAPX 212048
SVSAPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE GAYLORD MI
448 PM EDT SUN AUG 21 2011

MIC007-212058-
/O.CAN.KAPX.SV.W.0077.000000T0000Z-110821T2100Z/
ALPENA MI-
448 PM EDT SUN AUG 21 2011

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN ALPENA COUNTY IS
CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED AND MOVED OUT OF
THE WARNED AREA.

LAT...LON 4501 8327 4507 8339 4505 8343 4494 8343
      4490 8337 4486 8354 4499 8364 4516 8334
      4509 8330 4508 8331 4506 8330 4505 8328
      4503 8325 4502 8325
TIME...MOT...LOC 2048Z 312DEG 27KT 4491 8311
WIND...HAIL <50MPH <.50IN

$$

The office that day

Everything else NWS Gaylord, MI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 21, 12:13 AM EDTSpecial Marine WarningAPX47 min
Aug 21, 10:33 AM EDTSpecial Marine WarningAPX57 min
Aug 21, 10:56 AM EDTSmall Craft AdvisoryAPX18 hr
Aug 21, 12:57 PM EDTTornado WarningAPXAlcona, Iosco48 min
Aug 21, 1:19 PM EDTSpecial Marine WarningAPX86 min
Aug 21, 2:15 PM EDTSpecial Marine WarningAPX40 min
Aug 21, 4:10 PM EDTSpecial Marine WarningAPX60 min
Aug 21, 5:23 PM EDTSpecial Marine WarningAPX80 min

Nearby

Severe Thunderstorm Warnings in Michigan, 2011Every severe thunderstorm warning in 2011

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.