Alert archive / Michigan / Mesoscale Discussions in 2011

Mesoscale Discussion 402

April 10, 201132 counties in Michigan; 13 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Apr 10, 2011, 9:55 PM EDT for 32 counties in Michigan; 13 counties in Wisconsin. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Apr 10, 2011, 9:55 PM EDT (01:55 UTC)
Expired
Apr 10, 2011, 11:30 PM EDT
In force
95 min
Issued by
the Storm Prediction Center
All 45 counties

Alger County, MI, Alpena County, MI, Antrim County, MI, Benzie County, MI, Charlevoix County, MI, Cheboygan County, MI, Chippewa County, MI, Clare County, MI, Crawford County, MI, Delta County, MI, Dickinson County, MI, Emmet County, MI, Grand Traverse County, MI, Kalkaska County, MI, Lake County, MI, Leelanau County, MI, Luce County, MI, Mackinac County, MI, Manistee County, MI, Marquette County, MI, Mason County, MI, Menominee County, MI, Missaukee County, MI, Montmorency County, MI, Oceana County, MI, Ogemaw County, MI, Osceola County, MI, Oscoda County, MI, Otsego County, MI, Roscommon County, MI, Schoolcraft County, MI, Wexford County, MI, Brown County, WI, Calumet County, WI, Dodge County, WI, Door County, WI, Fond du Lac County, WI, Jefferson County, WI, Kewaunee County, WI, Manitowoc County, WI, Milwaukee County, WI, Ozaukee County, WI, Sheboygan County, WI, Washington County, WI, Waukesha County, WI

The radar

The Green Bay radar (KGRB), 134 km from the middle of the area, began a volume at 01:56 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, 1.9 hours before the alert went out and 134 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 00:00Z on 2011-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1647 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 00:00Z on 2011-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 399 square meters per square second.1939587897117Sfc1 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
1647 J/kg
Mixed-layer CIN
-38 J/kg
Mixed-layer LCL
1073 m above ground
0-6 km bulk shear
74 kt
0-1 km storm-relative helicity
399 m²/s²
0-3 km storm-relative helicity
397 m²/s²
Significant tornado parameter
4.2
Supercell composite
11.4

Open this sounding in Storm Lab

The text

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

504 
ACUS11 KWNS 110155
SWOMCD
SPC MCD 110155 
MIZ000-WIZ000-110330-

MESOSCALE DISCUSSION 0402
NWS STORM PREDICTION CENTER NORMAN OK
0855 PM CDT SUN APR 10 2011

AREAS AFFECTED...ERN WISCONSIN...UPPER PENINSULA OF MICHIGAN...NRN
LWR MICHIGAN

CONCERNING...TORNADO WATCH 120...121...

VALID 110155Z - 110330Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 120...121...CONTINUES.

THROUGH 04Z...THE CENTER OF THE DEEP AND SLOWLY DEEPENING SURFACE
CYCLONE APPEARS LIKELY TO CONTINUE MIGRATING EAST NORTHEASTWARD
ACROSS LAKE SUPERIOR...WITH THE TRAILING COLD FRONT PROGRESSING
THROUGH MUCH OF THE REMAINDER OF EASTERN WISCONSIN.  FORCING
ASSOCIATED WITH A STRONGLY DIVERGENT UPPER FLOW FIELD IS EXPECTED TO
SPREAD ACROSS THE REMAINDER OF THE UPPER PENINSULA OF MICHIGAN AND
NORTHERN LOWER MICHIGAN...WHICH PROBABLY WILL BE ACCOMPANIED BY
CONTINUING CONVECTIVE DEVELOPMENT IN THE PRESENCE OF WEAK TO
MODERATE INSTABILITY.  WITH A SOUTHWESTERLY 500 MB JET PROGGED TO
STRENGTHEN IN EXCESS OF 100 KT AS IT NOSES NORTHEAST OF THE UPPER
MISSISSIPPI VALLEY...AND WARM SECTOR 850 MB FLOW STRENGTHENING FROM
50-70+ KT WHILE VEERING FROM SOUTHERLY TO SOUTHWESTERLY... POTENTIAL
FOR STRONG DAMAGING WIND GUSTS MAY INCREASE FURTHER THIS EVENING. 
WHILE THE TENDENCY MAY BE FOR ORGANIZING STORM
CLUSTERS...PARTICULARLY ACROSS NORTHERN LOWER MICHIGAN...DISCRETE
SUPERCELLS CAPABLE OF PRODUCING TORNADOES WILL REMAIN A POSSIBILITY.

..KERR.. 04/11/2011

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

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

LAT...LON   44968802 46048791 46658797 46908734 47108515 46248389
            44918332 44258362 43858533 43738597 42838785 42958912
            44218828 44968802

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 10, 9:17 PM EDTTornado WatchSPCAlger, Baraga, Chippewa, Delta, Dickinson, Luce and 4 more4 hr
Apr 11, 12:03 AM EDTMesoscale DiscussionSPCAllegan, Barry, Berrien, Calhoun, Cass, Clinton and 12 more87 min
Apr 11, 1:48 AM EDTMesoscale DiscussionSPCBranch, Hillsdale, Lenawee, Saint Joseph87 min

Nearby

Mesoscale Discussions in Michigan, 2011Mesoscale Discussions in Wisconsin, 2011Every 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.