Alert archive / Michigan / Mesoscale Discussions in 2021

Mesoscale Discussion 926

June 11, 202113 counties in Michigan

The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2021, 4:26 PM EDT for 13 counties in Michigan. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
Jun 11, 2021, 4:26 PM EDT (20:26 UTC)
Expired
Jun 11, 2021, 6:00 PM EDT
In force
94 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
5%

Counties Bay County, MI, Clare County, MI, Clinton County, MI, Gladwin County, MI, Gratiot County, MI, Ionia County, MI, Isabella County, MI, Mecosta County, MI, Midland County, MI, Montcalm County, MI, Osceola County, MI, Saginaw County, MI, Shiawassee County, MI

The radar

The Grand Rapids radar (KGRR), 88 km from the middle of the area, began a volume at 20:26 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

Detroit, MI (KDTX), launched 12:00Z, 8.4 hours before the alert went out and 135 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 2021-06-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 94 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, Detroit, MI at 12:00Z on 2021-06-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -20 square meters per square second.1939Sfc1 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
94 J/kg
Mixed-layer CIN
-126 J/kg
Mixed-layer LCL
1136 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
-20 m²/s²
0-3 km storm-relative helicity
-19 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

As transmitted.

546 
ACUS11 KWNS 112027
SWOMCD
SPC MCD 112026 
MIZ000-112200-

Mesoscale Discussion 0926
NWS Storm Prediction Center Norman OK
0326 PM CDT Fri Jun 11 2021

Areas affected...portions of central Lower Michigan

Concerning...Severe potential...Watch unlikely 

Valid 112026Z - 112200Z

Probability of Watch Issuance...5 percent

SUMMARY...A strong wind gust or two may accompany an ongoing storm
cluster over the next couple of hours. A WW issuance is not
expected.

DISCUSSION...Isolated single-cell storms have recently conglomerated
into a loosely organized multicellular cluster. MRMS mosaic radar
data shows some leading-line organization with the cluster,
suggesting that modest cold pool development is underway, and may
lead to continued southward propagation over the next couple of
hours. 19Z RAP forecast soundings suggest that a well-mixed boundary
layer and around 750 J/kg MLCAPE are in place. As such, a strong to
potentially damaging wind gust remains possible with the
leading-line. Nonetheless, the severe threat is expected to remain
too sparse to warrant a WW issuance.

..Squitieri/Grams.. 06/11/2021

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

ATTN...WFO...DTX...APX...GRR...

LAT...LON   44208542 44138448 43868392 43548381 43208388 42798419
            42658457 42698490 42978537 43278558 43808567 44208542

Nearby

Mesoscale Discussions in Michigan, 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.