Alert archive / Michigan / Tornado Watches in 2021

Tornado Watch 322

June 26, 202118 counties in Michigan

The Storm Prediction Center issued this tornado watch at Jun 26, 2021, 4:04 PM EDT for 18 counties in Michigan. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jun 26, 2021, 4:04 PM EDT (20:04 UTC)
Expired
Jun 26, 2021, 10:00 PM EDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt

Counties Arenac County, MI, Bay County, MI, Genesee County, MI, Gladwin County, MI, Huron County, MI, Iosco County, MI, Lapeer County, MI, Livingston County, MI, Macomb County, MI, Midland County, MI, Oakland County, MI, Ogemaw County, MI, Saginaw County, MI, Saint Clair County, MI, Sanilac County, MI, Shiawassee County, MI, Tuscola County, MI, Washtenaw County, MI

The radar

The Detroit radar (KDTX), 113 km from the middle of the area, began a volume at 20:03 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
50%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

10 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jun 26, 4:45 PM EDTTornado WarningDTXBay30 min
Jun 26, 5:32 PM EDTSevere Thunderstorm WarningDTXShiawassee58 min
Jun 26, 5:42 PM EDTSevere Thunderstorm WarningDTXSaginaw50 min
Jun 26, 6:05 PM EDTTornado WarningDTXShiawassee55 min
Jun 26, 6:10 PM EDTSevere Thunderstorm WarningDTXGenesee80 min
Jun 26, 6:17 PM EDTTornado WarningDTXGenesee43 min
Jun 26, 6:41 PM EDTSevere Thunderstorm WarningDTXLivingston79 min
Jun 26, 6:43 PM EDTTornado WarningDTXGenesee42 min
Jun 26, 6:49 PM EDTSevere Thunderstorm WarningDTXLapeer43 min
Jun 26, 7:38 PM EDTTornado WarningDTXLivingston35 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Detroit, MI (KDTX), launched 12:00Z, 8.1 hours before the alert went out and 111 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, Detroit, MI at 12:00Z on 2021-06-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 492 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, Detroit, MI at 12:00Z on 2021-06-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 90 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
492 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
493 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
90 m²/s²
0-3 km storm-relative helicity
139 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.5

Open this sounding in Storm Lab

The text

As transmitted.

244 
WWUS20 KWNS 262002
SEL2  
SPC WW 262002
MIZ000-LHZ000-270200-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 322
NWS Storm Prediction Center Norman OK
405 PM EDT Sat Jun 26 2021

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Eastern Lower Michigan
  Lake Huron

* Effective this Saturday afternoon and evening from 405 PM until
  1000 PM EDT.

* Primary threats include...
  A few tornadoes possible
  Scattered damaging wind gusts to 70 mph possible
  Scattered large hail events to 1 inch in diameter possible

SUMMARY...Thunderstorms over western Lower Michigan will track
eastward this afternoon across the watch area.  A few supercell
storms are possible, capable of damaging wind gusts and isolated
tornadoes.

The tornado watch area is approximately along and 60 statute miles
north and south of a line from 30 miles west southwest of Saginaw MI
to 35 miles east of Bad Axe MI. For a complete depiction of the
watch see the associated watch outline update (WOUS64 KWNS WOU2).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 321...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1 inch. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 23035.

...Hart

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 26, 1:05 PM EDTTornado WatchSPCAllegan, Barry, Berrien, Branch, Calhoun, Cass and 17 more9 hr
Jun 26, 1:48 PM EDTMesoscale DiscussionSPCAllegan, Barry, Bay, Berrien, Calhoun, Cass and 15 more57 min
Jun 26, 3:47 PM EDTMesoscale DiscussionSPCBranch, Calhoun, Cass, Eaton, Genesee, Hillsdale and 6 more118 min
Jun 26, 7:08 PM EDTMesoscale DiscussionSPCAlcona, Allegan, Arenac, Barry, Bay, Berrien and 37 more67 min

Nearby

Tornado Watches in Michigan, 2021Every tornado watch 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.