Alert archive / Michigan / Special Marine Warnings in 2021

Special Marine Warning 21, NWS Gaylord, MI

July 27, 2021

NWS Gaylord, MI issued this special marine warning at Jul 27, 2021, 1:13 AM EDT. It was in force for 32 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
Jul 27, 2021, 1:13 AM EDT (05:13 UTC)
Expired
Jul 27, 2021, 1:45 AM EDT
In force
32 min
Issued by
NWS Gaylord, MI
Area
Storm-based polygon
Hail
0.75 in
Wind
34.0 mph

The radar

The NCL Michigan radar (KAPX), 128 km from the middle of the area, began a volume at 05:15 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 00:00Z, 5.2 hours before the alert went out and 239 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 00:00Z on 2021-07-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 36 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 00:00Z on 2021-07-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 105 square meters per square second.1939587897Sfc1 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
36 J/kg
Mixed-layer CIN
-102 J/kg
Mixed-layer LCL
2075 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
105 m²/s²
0-3 km storm-relative helicity
182 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted.

657 
WHUS53 KAPX 270513
SMWAPX
LMZ341-362-270545-
/O.NEW.KAPX.MA.W.0021.210727T0513Z-210727T0545Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Gaylord MI
113 AM EDT Tue Jul 27 2021

The National Weather Service in Gaylord has issued a

* Special Marine Warning for...
  Lake Michigan South of a line from Seul Choix Point to the Mackinac
  Bridge and North of a line from Charlevoix MI to South Fox Island
  5NM offshore...
  Seul Choix Point to 5NM West of Mackinac Bridge...

* Until 145 AM EDT.

* At 113 AM EDT, a severe thunderstorm was located near Epoufette, or
  16 nm northeast of Point Patterson, moving east at 40 knots.

  HAZARD...Wind gusts 34 knots or greater and large hail.

  SOURCE...Radar.

  IMPACT...Small craft could be damaged in briefly higher winds and 
           suddenly higher waves. Large hail could result in 
           structural damage.

* Locations impacted include...
  Point Aux Chenes, Epoufette, Naubinway and Brevort. 

LAT...LON 4605 8498 4595 8484 4582 8485 4596 8555
      4613 8552 4615 8541
TIME...MOT...LOC 0513Z 276DEG 40KT 4608 8528 

HAIL...>.75IN
WIND...>34KTS

$$

JSL
1 follow-up statement
782 
FZUS73 KAPX 270525
MWSAPX

Marine Weather Statement
National Weather Service Gaylord MI
125 AM EDT Tue Jul 27 2021

LMZ341-362-270545-
/O.CON.KAPX.MA.W.0021.000000T0000Z-210727T0545Z/
125 AM EDT Tue Jul 27 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 145 AM EDT...

For the following areas...
Lake Michigan South of a line from Seul Choix Point to the Mackinac
Bridge and North of a line from Charlevoix MI to South Fox Island 5NM
offshore...
Seul Choix Point to 5NM West of Mackinac Bridge...

At 125 AM EDT, a severe thunderstorm was located over Epoufette, or
15 nm northwest of Point Aux Chenes, moving east at 35 knots.

HAZARD...Wind gusts 34 knots or greater and large hail.

SOURCE...Radar indicated.

IMPACT...Small craft could be damaged in briefly higher winds and 
         suddenly higher waves. Large hail could result in 
         structural damage.

Locations impacted include...
Point Aux Chenes, Epoufette, Naubinway and Brevort. 

LAT...LON 4605 8498 4595 8484 4582 8485 4596 8555
      4613 8552 4615 8541
TIME...MOT...LOC 0525Z 282DEG 37KT 4604 8524 

HAIL...>.75IN
WIND...>34KTS

$$

JSL

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 12:43 AM EDTSpecial Weather StatementAPXMackinac47 min
Jul 27, 12:50 AM EDTSevere Thunderstorm WarningAPXMackinac40 min
Jul 27, 2:17 AM EDTSpecial Marine WarningAPX88 min
Jul 27, 2:59 AM EDTSpecial Weather StatementAPXCheboygan61 min

Nearby

Special Marine Warnings in Michigan, 2021Every special marine 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.