Alert archive / Michigan / Mesoscale Discussions in 2011

Mesoscale Discussion 734

May 11, 201120 counties in Michigan; 16 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at May 11, 2011, 2:16 PM EDT for 20 counties in Michigan; 16 counties in Wisconsin. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued
May 11, 2011, 2:16 PM EDT (18:16 UTC)
Expired
May 11, 2011, 4:15 PM EDT
In force
119 min
Issued by
the Storm Prediction Center
All 36 counties

Arenac County, MI, Bay County, MI, Benzie County, MI, Clare County, MI, Crawford County, MI, Gladwin County, MI, Grand Traverse County, MI, Isabella County, MI, Kalkaska County, MI, Lake County, MI, Manistee County, MI, Mason County, MI, Mecosta County, MI, Midland County, MI, Missaukee County, MI, Ogemaw County, MI, Osceola County, MI, Roscommon County, MI, Tuscola County, MI, Wexford County, MI, Brown County, WI, Door County, WI, Forest County, WI, Kewaunee County, WI, Langlade County, WI, Lincoln County, WI, Manitowoc County, WI, Marathon County, WI, Marinette County, WI, Menominee County, WI, Oconto County, WI, Oneida County, WI, Outagamie County, WI, Price County, WI, Shawano County, WI, Taylor County, WI

The radar

The Green Bay radar (KGRB), 122 km from the middle of the area, began a volume at 18:16 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 6.3 hours before the alert went out and 122 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 2011-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2011-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 102 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
782 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
102 m²/s²
0-3 km storm-relative helicity
105 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

041 
ACUS11 KWNS 111817
SWOMCD
SPC MCD 111816
MIZ000-WIZ000-112015-

MESOSCALE DISCUSSION 0734
NWS STORM PREDICTION CENTER NORMAN OK
0116 PM CDT WED MAY 11 2011

AREAS AFFECTED...NRN/CNTRL LOWER MI...A SMALL PART OF SRN UPPER
MI...NRN WI

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 111816Z - 112015Z

ISOLATED SVR STORMS POSING A THREAT FOR MARGINALLY SVR HAIL WILL
PERSIST THROUGH THE AFTERNOON ACROSS PORTIONS OF NRN/CNTRL LOWER
MI...A SMALL PART OF SRN UPPER MI...AND NRN WI.

DEEP...ELEVATED CONVECTIVE CORES ARE DEVELOPING/PERSISTING AT THE
NRN APEX OF A PLUME OF STEEP 700-500-MB LAPSE RATES IN EXCESS OF 7.5
C PER KM EXTENDING NWD INTO THE GREAT LAKES REGION. THIS WILL
PROVIDE ADEQUATE INSTABILITY /MUCAPE VALUES AOA 1000 J PER KG/ FOR
THE CONVECTION TO PERSIST THROUGH THE AFTERNOON HOURS. THIS ACTIVITY
WILL REMAIN ROOTED ABOVE THE SURFACE -- I.E. BETWEEN 900 AND 850 MB
PER RAPID REFRESH FORECAST SOUNDINGS -- WITH THE SFC BAROCLINIC ZONE
DISPLACED WELL TO THE SOUTH OF THE CONVECTION /ACROSS SRN MI AND SRN
WI/. GIVEN EFFECTIVE BULK SHEAR MAGNITUDES GENERALLY AOB 30 KT...THE
PRIMARY CONVECTIVE MODE WILL BE MULTICELLULAR...WITH LIMITED THREAT
FOR INDIVIDUALLY SUSTAINED CONVECTIVE CORES. THE PRIMARY SVR THREAT
WILL BE MARGINALLY SVR HAIL...ON AN ISOLATED BASIS.
ADDITIONALLY...WITH AN INFLUX OF DEEP-LAYER MOISTURE FEATURING PWAT
VALUES IN EXCESS OF 1.4 INCHES PER AMSU/SSMI TPW PRODUCT...HEAVY
RAINFALL WILL BE A THREAT WITH THIS ACTIVITY...PARTICULARLY WITH ANY
CONVECTIVE TRAINING /AS NOTED ACROSS PORTIONS OF NWRN LOWER MI/.

..COHEN.. 05/11/2011

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

ATTN...WFO...DTX...APX...GRR...MQT...GRB...DLH...ARX...MPX...

LAT...LON   43778633 44158787 44538903 45309100 45849040 45828900
            45468725 45058589 44638417 44428343 43948306 43488336
            43468486 43778633

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 11, 4:19 AM EDTMesoscale DiscussionSPCDelta, Dickinson, Iron, Marquette, Menominee56 min
May 11, 6:40 PM EDTMesoscale DiscussionSPCAllegan, Berrien, Cass, Saint Joseph, Van Buren65 min
May 11, 6:56 PM EDTSevere Thunderstorm WatchSPCAllegan, Barry, Berrien, Branch, Calhoun, Cass and 3 more5 hr
May 10, 9:45 PM EDTMesoscale DiscussionSPCBuffalo, Crawford, Dunn, Eau Claire, Iowa, Jackson and 10 more90 min
May 11, 1:55 PM EDTMesoscale DiscussionSPCAdams, Columbia, Dane, Dodge, Green, Green Lake and 12 more65 min
May 11, 2:23 PM EDTSevere Thunderstorm WatchSPCAdams, Calumet, Clark, Columbia, Crawford, Dane and 26 more6 hr
May 11, 4:38 PM EDTMesoscale DiscussionSPCAdams, Brown, Calumet, Clark, Columbia, Crawford and 34 more2 hr

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.