Alert archive / Michigan / Mesoscale Discussions in 2011

Mesoscale Discussion 873

May 22, 2011Dickinson County, Iron County, Michigan; Florence County, Vilas County, Wisconsin

The Storm Prediction Center issued this mesoscale discussion at May 22, 2011, 7:42 PM CDT for Dickinson County, Iron County, Michigan; Florence County, Vilas County, Wisconsin. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued: May 22, 2011, 7:42 PM CDT (00:42 UTC)
Expired: May 22, 2011, 8:45 PM CDT
In force: 63 min
Issued by: the Storm Prediction Center

Counties Dickinson County, MI, Iron County, MI, Florence County, WI, Vilas County, WI

The radar

The Marquette radar (KMQT), 123 km from the middle of the area, began a volume at 00:44 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 00:00Z, 0.7 hours before the alert went out and 179 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 753 J/kg
Mixed-layer CIN: -97 J/kg
Mixed-layer LCL: 942 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 242 m²/s²
0-3 km storm-relative helicity: 325 m²/s²
Significant tornado parameter: 1.1
Supercell composite: 7.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

169 
ACUS11 KWNS 230042
SWOMCD
SPC MCD 230042 
WIZ000-MIZ000-230145-

MESOSCALE DISCUSSION 0873
NWS STORM PREDICTION CENTER NORMAN OK
0742 PM CDT SUN MAY 22 2011

AREAS AFFECTED...NRN WI INTO WRN UPPER MI

CONCERNING...TORNADO WATCH 331...

VALID 230042Z - 230145Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 331 CONTINUES.

A SMALL WINDOW EXIST NEXT 30 MIN OR SO FOR AN ISOLATED TORNADO OVER
EXTREME NRN WI INTO WRN UPPER MI...BUT OVERALL THREAT IS BECOMING
INCREASINGLY MARGINAL.

A BRIEF TORNADO REMAINS POSSIBLE AS STORMS CROSS THE BOUNDARY OVER
EXTREME NRN WI INTO WRN PARTS OF LOWER MI WHERE SHEAR PROFILES AND
HODOGRAPHS REMAIN FAVORABLE. HOWEVER...THE BOUNDARY LAYER HAS BEEN
STABILIZED BY PREVIOUS AND ONGOING CONVECTION...AND WITH LOSS OF
DIABATIC WARMING...OVERALL THREAT SHOULD CONTINUE TO WANE.

..DIAL.. 05/23/2011

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...MQT...GRB...DLH...

LAT...LON   45708793 45798916 45849032 46289040 46448913 46118772
            45708793

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 22, 7:09 PM CDT	Mesoscale Discussion	SPC	Antrim, Crawford, Grand Traverse, Kalkaska, Lake, Missaukee and 3 more	96 min
May 22, 7:20 PM CDT	Mesoscale Discussion	SPC	Allegan, Barry, Berrien, Branch, Calhoun, Cass and 17 more	115 min
May 22, 9:59 PM CDT	Mesoscale Discussion	SPC	Allegan, Barry, Berrien, Branch, Calhoun, Cass and 5 more	61 min
May 23, 7:25 AM CDT	Mesoscale Discussion	SPC	Lenawee, Monroe, Washtenaw, Wayne	65 min
May 23, 11:35 AM CDT	Mesoscale Discussion	SPC	Arenac, Bay, Branch, Calhoun, Clinton, Eaton and 21 more	85 min
May 23, 1:15 PM CDT	Severe Thunderstorm Watch	SPC	Branch, Calhoun, Genesee, Hillsdale, Huron, Ingham and 13 more	8 hr
May 23, 5:40 PM CDT	Mesoscale Discussion	SPC	Hillsdale, Jackson, Lenawee, Livingston, Macomb, Monroe and 4 more	65 min

Nearby

Mesoscale Discussions in Michigan, 2011 Mesoscale Discussions in Wisconsin, 2011 Every mesoscale discussion in 2011

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.