Alert archive / Wisconsin / Mesoscale Discussions in 2012

Mesoscale Discussion 673

May 3, 20128 counties in Minnesota; 32 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at May 3, 2012, 8:43 AM CDT for 8 counties in Minnesota; 32 counties in Wisconsin. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued
May 3, 2012, 8:43 AM CDT (13:43 UTC)
Expired
May 3, 2012, 10:15 AM CDT
In force
92 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 40 counties

Dakota County, MN, Dodge County, MN, Goodhue County, MN, Olmsted County, MN, Rice County, MN, Steele County, MN, Wabasha County, MN, Winona County, MN, Adams County, WI, Brown County, WI, Buffalo County, WI, Calumet County, WI, Clark County, WI, Columbia County, WI, Dodge County, WI, Eau Claire County, WI, Fond du Lac County, WI, Green Lake County, WI, Jackson County, WI, Juneau County, WI, La Crosse County, WI, Manitowoc County, WI, Marathon County, WI, Marquette County, WI, Monroe County, WI, Outagamie County, WI, Ozaukee County, WI, Pepin County, WI, Pierce County, WI, Portage County, WI, Richland County, WI, Sauk County, WI, Shawano County, WI, Sheboygan County, WI, Trempealeau County, WI, Washington County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI, Wood County, WI

The radar

The La Crosse radar (KARX), 48 km from the middle of the area, began a volume at 13:46 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, 1.7 hours before the alert went out and 216 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 2012-05-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 321 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 2012-05-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 160 square meters per square second.19395878Sfc1 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
321 J/kg
Mixed-layer CIN
-146 J/kg
Mixed-layer LCL
565 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
160 m²/s²
0-3 km storm-relative helicity
220 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8

Open this sounding in Storm Lab

The text

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

972 
ACUS11 KWNS 031344
SWOMCD
SPC MCD 031343
WIZ000-MNZ000-031515-

MESOSCALE DISCUSSION 0673
NWS STORM PREDICTION CENTER NORMAN OK
0843 AM CDT THU MAY 03 2012

AREAS AFFECTED...SERN MN...CNTRL/SRN WI

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 031343Z - 031515Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...STRONG STORMS WILL SPREAD ACROSS PORTIONS OF CNTRL/SRN WI
AND PORTIONS OF SERN MN THIS MORNING...A FEW STRONGER UPDRAFTS MAY
PRODUCE HAIL.

DISCUSSION...CONVECTION HAS REJUVENATED ALONG LEADING EDGE OF
OVERNIGHT MCS...CURRENTLY EXTENDING FROM PORTIONS OF SERN MN INTO
CNTRL WI.  DESPITE THE APPARENT LACK OF LARGE SCALE SUPPORT ACROSS
THIS REGION FOR UPWARD GROWTH...A FAIRLY EXTENSIVE CORRIDOR OF TSTMS
IS EVOLVING ALONG THIS CORRIDOR WHERE MUCAPE RANGES FROM 1500-2500
J/KG.  12Z SOUNDINGS FROM BOTH MSP AND GRB SUPPORT ROBUST SLIGHTLY
ELEVATED UPDRAFTS ROOTED WITHIN 1 KM OF SFC.  BOUNDARY LAYER HEATING
ALONG SRN FRINGE OF THIS ACTIVITY SHOULD ENABLE STRONGER UPDRAFTS TO
EVOLVE LATER THIS MORNING.  AT THIS TIME DO NOT ANTICIPATE A SEVERE
THUNDERSTORM WATCH FOR THE ELEVATED CONVECTION BUT POSSIBLY FOR
LATER CONVECTION WHERE PARTIAL SUNSHINE WILL AID LOW LEVEL LAPSE
RATES.

..DARROW.. 05/03/2012

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

ATTN...WFO...GRB...MKX...ARX...MPX...

LAT...LON   44799340 45078966 44538734 43098788 43129028 43769081
            43969345 44799340

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 2, 7:20 PM CDTMesoscale DiscussionSPCBig Stone, Clay, Grant, Traverse, Wilkin55 min
May 2, 7:38 PM CDTMesoscale DiscussionSPCBlue Earth, Brown, Cottonwood, Dodge, Faribault, Fillmore and 16 more37 min
May 2, 7:47 PM CDTSevere Thunderstorm WatchSPCDodge, Fillmore, Houston, Mower, Olmsted, Wabasha and 1 more5 hr
May 2, 9:18 PM CDTMesoscale DiscussionSPCBlue Earth, Brown, Cottonwood, Faribault, Freeborn, Goodhue and 10 more27 min
May 2, 11:06 PM CDTMesoscale DiscussionSPCAnoka, Big Stone, Carver, Chippewa, Dakota, Hennepin and 17 more24 min
May 2, 11:51 PM CDTMesoscale DiscussionSPCAdams, Brown, Calumet, Clark, Columbia, Dodge and 20 more54 min
May 3, 10:34 AM CDTMesoscale DiscussionSPCCalumet, Dane, Dodge, Fond du Lac, Green Lake, Jefferson and 8 more86 min
May 3, 1:07 PM CDTSevere Thunderstorm WatchSPCColumbia, Dane, Dodge, Green, Jefferson, Kenosha and 7 more6 hr
May 3, 2:53 PM CDTMesoscale DiscussionSPCColumbia, Dane, Dodge, Jefferson, Kenosha, Milwaukee and 5 more67 min

Nearby

Mesoscale Discussions in Wisconsin, 2012Mesoscale Discussions in Minnesota, 2012Every mesoscale discussion in 2012

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.