Alert archive / Minnesota / Mesoscale Discussions in 2012

Mesoscale Discussion 667

May 2, 201222 counties in Minnesota; 10 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at May 2, 2012, 7:38 PM CDT for 22 counties in Minnesota; 10 counties in Wisconsin. It was in force for 37 min.

The area

The outline as issued.

The facts

Issued: May 2, 2012, 7:38 PM CDT (00:38 UTC)
Expired: May 2, 2012, 8:15 PM CDT
In force: 37 min
Issued by: the Storm Prediction Center

All 32 counties

Blue Earth County, MN, Brown County, MN, Cottonwood County, MN, Dodge County, MN, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Goodhue County, MN, Houston County, MN, Jackson County, MN, Le Sueur County, MN, Martin County, MN, Mower County, MN, Nicollet County, MN, Nobles County, MN, Olmsted County, MN, Rice County, MN, Steele County, MN, Wabasha County, MN, Waseca County, MN, Watonwan County, MN, Winona County, MN, Adams County, WI, Buffalo County, WI, Jackson County, WI, Juneau County, WI, La Crosse County, WI, Monroe County, WI, Pepin County, WI, Trempealeau County, WI, Vernon County, WI, Wood County, WI

The radar

The Minneapolis radar (KMPX), 102 km from the middle of the area, began a volume at 00:37 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.

Severe Thunderstorm Watch 227May 2, 7:45 PM CDT

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 0.6 hours before the alert went out and 104 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: 84 J/kg
Mixed-layer CIN: -59 J/kg
Mixed-layer LCL: 1937 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 21 m²/s²
0-3 km storm-relative helicity: 134 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

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

984 
ACUS11 KWNS 030039
SWOMCD
SPC MCD 030038
WIZ000-IAZ000-MNZ000-030115-

MESOSCALE DISCUSSION 0667
NWS STORM PREDICTION CENTER NORMAN OK
0738 PM CDT WED MAY 02 2012

AREAS AFFECTED...SRN MN INTO WRN/CENTRAL WI

CONCERNING...SEVERE THUNDERSTORM WATCH 225...

VALID 030038Z - 030115Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 225
CONTINUES.

SUMMARY...A NEW WW WILL BE COORDINATED SOON FOR WRN WI.

SVR WEATHER THREAT CONTINUES ACROSS SRN/SRN MN WITH ACTIVITY
EXPECTED TO PERSIST AND MOVE INTO WRN WI.  HAIL AND STRONG WIND
GUSTS WILL REMAIN THE PRIMARY THREATS.

DISCUSSION...REGIONAL RADAR IMAGERY SHOWED SEVERAL STRONG TO SEVERE
STORMS EXTENDING FROM SOUTH CENTRAL INTO SRN MN...WITH ACTIVITY
EXPECTED TO MOVE INTO WRN WI SOON.  THE AIR MASS DOWNSTREAM OVER WRN
WI IS GRADUALLY DESTABILIZING WITH SIMILAR BULK SHEAR TO OVER SRN MN
/UP TO 50 KT/ FAVORING ORGANIZED STORMS.  STEEP LAPSE RATES FAVOR A
THREAT FOR HAIL AND DAMAGING WINDS.

..PETERS.. 05/03/2012

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

ATTN...WFO...GRB...MKX...ARX...MPX...DMX...FSD...

LAT...LON   44129569 44479458 44679231 44689034 44288958 43608959
            43469144 43509338 43549516 43589592 44129569

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 2, 7:20 PM CDT	Mesoscale Discussion	SPC	Big Stone, Clay, Grant, Traverse, Wilkin	55 min
May 2, 7:47 PM CDT	Severe Thunderstorm Watch	SPC	Dodge, Fillmore, Houston, Mower, Olmsted, Wabasha and 1 more	5 hr
May 2, 9:18 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Brown, Cottonwood, Faribault, Freeborn, Goodhue and 10 more	27 min
May 2, 11:06 PM CDT	Mesoscale Discussion	SPC	Anoka, Big Stone, Carver, Chippewa, Dakota, Hennepin and 17 more	24 min
May 3, 8:43 AM CDT	Mesoscale Discussion	SPC	Dakota, Dodge, Goodhue, Olmsted, Rice, Steele and 2 more	92 min
May 2, 11:51 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Calumet, Clark, Columbia, Dodge and 20 more	54 min
May 3, 10:34 AM CDT	Mesoscale Discussion	SPC	Calumet, Dane, Dodge, Fond du Lac, Green Lake, Jefferson and 8 more	86 min
May 3, 1:07 PM CDT	Severe Thunderstorm Watch	SPC	Columbia, Dane, Dodge, Green, Jefferson, Kenosha and 7 more	6 hr
May 3, 2:53 PM CDT	Mesoscale Discussion	SPC	Columbia, Dane, Dodge, Jefferson, Kenosha, Milwaukee and 5 more	67 min

Nearby

Mesoscale Discussions in Minnesota, 2012 Mesoscale Discussions in Wisconsin, 2012 Every 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.