Alert archive / Michigan / Mesoscale Discussions in 2021

Mesoscale Discussion 1156

July 5, 202126 counties in Michigan; 13 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jul 5, 2021, 3:47 PM EDT for 26 counties in Michigan; 13 counties in Wisconsin. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued
Jul 5, 2021, 3:47 PM EDT (19:47 UTC)
Expired
Jul 5, 2021, 5:45 PM EDT
In force
118 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%
All 39 counties

Alcona County, MI, Alpena County, MI, Antrim County, MI, Benzie County, MI, Charlevoix County, MI, Cheboygan County, MI, Clare County, MI, Crawford County, MI, Emmet County, MI, Gladwin County, MI, Grand Traverse County, MI, Iosco County, MI, Kalkaska County, MI, Lake County, MI, Leelanau County, MI, Manistee County, MI, Mason County, MI, Missaukee County, MI, Montmorency County, MI, Ogemaw County, MI, Osceola County, MI, Oscoda County, MI, Otsego County, MI, Presque Isle County, MI, Roscommon County, MI, Wexford County, MI, Brown County, WI, Calumet County, WI, Door County, WI, Kewaunee County, WI, Manitowoc County, WI, Menominee County, WI, Oconto County, WI, Outagamie County, WI, Portage County, WI, Shawano County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI

The radar

The Green Bay radar (KGRB), 133 km from the middle of the area, began a volume at 19:49 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

Green Bay/Straub, WI (KGRB), launched 12:00Z, 7.8 hours before the alert went out and 133 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, Green Bay/Straub, WI at 12:00Z on 2021-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 583 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, Green Bay/Straub, WI at 12:00Z on 2021-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 114 square meters per square second.193958Sfc1 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
583 J/kg
Mixed-layer CIN
-228 J/kg
Mixed-layer LCL
1248 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
114 m²/s²
0-3 km storm-relative helicity
105 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

056 
ACUS11 KWNS 051948
SWOMCD
SPC MCD 051947 
MIZ000-WIZ000-052145-

Mesoscale Discussion 1156
NWS Storm Prediction Center Norman OK
0247 PM CDT Mon Jul 05 2021

Areas affected...northeast Wisconsin into northern Lower Michigan

Concerning...Severe potential...Watch unlikely 

Valid 051947Z - 052145Z

Probability of Watch Issuance...20 percent

SUMMARY...A few storms may produce marginal wind or hail over the
next few  hours from eastern Wisconsin across northern Lower
Michigan.

DISCUSSION...A warm and moist air mass is in place ahead of a weak
front over northern WI, with westerly low-level mean winds spreading
this air mass eastward into Lower MI resulting in over 2000 J/kg
MLCAPE.

Most convection this afternoon has been focused along the western
shores of Lake Huron and Green Bay, but a gradual increase in
convection is occurring along the front farther west. In addition,
sporadic attempts have been noted across parts of northern Lower MI
as well, though lack of convergence is likely hampering further
development there.

As heating continues, storm coverage is expected to increase with
activity developing into northeast WI. Given the westerly low-level
feed of theta-e, some of this activity may eventually cross Lake MI,
where an unstable air mass awaits to the east. Though shear is weak,
mean wind speeds and ample PWAT suggest locally strong outflow winds
may occur, and the strongest cells may briefly produce marginal
hail.

..Jewell/Guyer.. 07/05/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...DTX...APX...GRR...MQT...GRB...MKX...ARX...

LAT...LON   43768563 43808740 43888865 44018955 44258973 44578976
            44948956 45258811 45508706 45788553 45768496 45648405
            45248323 44688298 44418324 43818444 43768563

Nearby

Mesoscale Discussions in Michigan, 2021Mesoscale Discussions in Wisconsin, 2021Every mesoscale discussion 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.