Alert archive / Michigan / Severe Thunderstorm Watches in 2022

Severe Thunderstorm Watch 252

May 20, 202222 counties in Michigan

The Storm Prediction Center issued this severe thunderstorm watch at May 20, 2022, 1:55 PM EDT for 22 counties in Michigan. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
May 20, 2022, 1:55 PM EDT (17:55 UTC)
Expired
May 20, 2022, 6:17 PM EDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 22 counties

Alcona County, MI, Alpena County, MI, Antrim County, MI, Benzie County, MI, Charlevoix County, MI, Cheboygan County, MI, Chippewa County, MI, Crawford County, MI, Emmet County, MI, Grand Traverse County, MI, Kalkaska County, MI, Leelanau County, MI, Mackinac County, MI, Manistee County, MI, Missaukee County, MI, Montmorency County, MI, Ogemaw County, MI, Oscoda County, MI, Otsego County, MI, Presque Isle County, MI, Roscommon County, MI, Wexford County, MI

The radar

The NCL Michigan radar (KAPX), 19 km from the middle of the area, began a volume at 17:58 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
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
40%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 20, 2:11 PM EDTSevere Thunderstorm WarningAPXBenzie, Grand Traverse, Leelanau49 min
May 20, 2:34 PM EDTSevere Thunderstorm WarningAPXCharlevoix26 min
May 20, 2:46 PM EDTSevere Thunderstorm WarningAPXAntrim, Charlevoix, Emmet, Grand Traverse, Kalkaska44 min
May 20, 2:52 PM EDTSevere Thunderstorm WarningAPXCheboygan, Emmet, Mackinac53 min
May 20, 3:24 PM EDTSevere Thunderstorm Warning Considerable damage threatAPXAntrim, Charlevoix, Cheboygan, Montmorency, Otsego55 min
May 20, 3:37 PM EDTSevere Thunderstorm WarningAPXChippewa, Mackinac53 min
May 20, 3:38 PM EDTTornado WarningAPXAntrim, Otsego22 min
May 20, 3:53 PM EDTSevere Thunderstorm Warning Considerable damage threatAPXCheboygan, Montmorency, Presque Isle50 min
May 20, 3:55 PM EDTTornado Warning Tornado observedAPXMontmorency, Otsego24 min
May 20, 4:24 PM EDTSevere Thunderstorm Warning Considerable damage threatAPXAlpena, Presque Isle38 min
May 20, 4:36 PM EDTTornado WarningAPXPresque Isle24 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

Alpena, MI (KAPX), launched 12:00Z, 5.9 hours before the alert went out and 193 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 2022-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 82 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Alpena, MI at 12:00Z on 2022-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 121 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
82 J/kg
Mixed-layer CIN
-240 J/kg
Mixed-layer LCL
1211 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
121 m²/s²
0-3 km storm-relative helicity
195 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

443 
WWUS20 KWNS 201752
SEL2  
SPC WW 201752
MIZ000-LHZ000-LMZ000-LSZ000-202300-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 252
NWS Storm Prediction Center Norman OK
155 PM EDT Fri May 20 2022

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Northern Lower Michigan
  Lake Huron
  Lake Michigan
  Lake Superior

* Effective this Friday afternoon and evening from 155 PM until
  700 PM EDT.

* Primary threats include...
  Scattered large hail and isolated very large hail events to 2
    inches in diameter possible
  Scattered damaging wind gusts to 70 mph possible
  A tornado or two possible

SUMMARY...A line of thunderstorms over Lake Michigan will track
quickly eastward this afternoon across northern Lower Michigan.  The
stronger cells along the line will pose a risk of locally damaging
wind gusts and large hail.  An isolated tornado or two is also
possible.

The severe thunderstorm watch area is approximately along and 70
statute miles east and west of a line from 35 miles southwest of
Houghton Lake MI to 35 miles east northeast of Sault Ste Marie MI.
For a complete depiction of the watch see the associated watch
outline update (WOUS64 KWNS WOU2).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for 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. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 251...

AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
24035.

...Hart

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 20, 1:32 PM EDTMesoscale DiscussionSPCAlcona, Alpena, Antrim, Arenac, Benzie, Charlevoix and 21 more2 hr
May 20, 3:52 PM EDTMesoscale DiscussionSPCMontmorency, Otsego, Presque Isle113 min

Nearby

Severe Thunderstorm Watches in Michigan, 2022Every severe thunderstorm watch in 2022

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.