Alert archive / Minnesota / Mesoscale Discussions in 2011

Mesoscale Discussion 1802

July 30, 201113 counties in Minnesota; 10 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jul 30, 2011, 11:07 PM CDT for 13 counties in Minnesota; 10 counties in Wisconsin. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued: Jul 30, 2011, 11:07 PM CDT (04:07 UTC)
Expired: Jul 31, 2011, 12:00 AM CDT
In force: 53 min
Issued by: the Storm Prediction Center

All 23 counties

Carver County, MN, Dakota County, MN, Goodhue County, MN, Hennepin County, MN, Le Sueur County, MN, McLeod County, MN, Nicollet County, MN, Ramsey County, MN, Rice County, MN, Scott County, MN, Sibley County, MN, Wabasha County, MN, Washington County, MN, Barron County, WI, Buffalo County, WI, Chippewa County, WI, Clark County, WI, Dunn County, WI, Eau Claire County, WI, Pepin County, WI, Pierce County, WI, Saint Croix County, WI, Taylor County, WI

The radar

The Minneapolis radar (KMPX), 70 km from the middle of the area, began a volume at 04:06 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

Minneapolis, MN (KMPX), launched 00:00Z, 4.1 hours before the alert went out and 73 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: 2387 J/kg
Mixed-layer CIN: -23 J/kg
Mixed-layer LCL: 1239 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 58 m²/s²
0-3 km storm-relative helicity: 176 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 8.4

Open this sounding in Storm Lab

The text

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

063 
ACUS11 KWNS 310408
SWOMCD
SPC MCD 310407
WIZ000-MNZ000-310500-

MESOSCALE DISCUSSION 1802
NWS STORM PREDICTION CENTER NORMAN OK
1107 PM CDT SAT JUL 30 2011

AREAS AFFECTED...SOUTHEAST MN/WESTERN WI

CONCERNING...SEVERE THUNDERSTORM WATCH 705...

VALID 310407Z - 310500Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 705
CONTINUES.

SEVERE TSTM WATCH 705 CONTINUES UNTIL 06Z. AN OVERALL WEAKENING
TREND IS EXPECTED TO CONTINUE TO OCCUR ACROSS SOUTHEAST
MN/WEST-CENTRAL WI OVER THE NEXT HOUR 1-2 HOURS...SUCH THAT AN
ADDITIONAL WATCH ISSUANCE IS NOT CURRENTLY ANTICIPATED. IN THE MEAN
TIME...DAMAGING WINDS/SEVERE HAIL WILL REMAIN POSSIBLE ON AN
INCREASINGLY ISOLATED BASIS.

SOUTHEASTWARD-MOVING STORMS HAVE CONGEALED/TRENDED MORE
OUTFLOW-DOMINANT ACROSS SOUTHEAST MN/TWIN CITIES VICINITY INTO
WEST-CENTRAL WI OVER THE PAST 1-2 HOURS. CONSISTENT WITH CURRENT
RADAR/SATELLITE TRENDS...THESE STORMS ARE LIKELY TO CONTINUE TO
WEAKEN AS THEY PROGRESSIVELY ENCOUNTER A MORE STABLE BOUNDARY LAYER
AND LOW LEVEL SURFACE RIDGING...COMBINED WITH A GENERALLY WANING
INSTABILITY FEED FROM THE WEST. WHILE AN INCREASINGLY
MARGINAL/ISOLATED SEVERE THREAT WILL LINGER...AN ADDITIONAL WATCH IS
UNLIKELY FOR FAR SOUTHERN MN/SOUTHWEST WI.

..GUYER.. 07/31/2011

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

ATTN...WFO...DLH...ARX...MPX...

LAT...LON   44439481 45049423 45269330 45469228 45479123 45399054
            44879035 44289141 44149378 44439481

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 30, 8:57 PM CDT	Mesoscale Discussion	SPC	Anoka, Benton, Carver, Chippewa, Chisago, Dakota and 20 more	93 min
Jul 31, 12:50 PM CDT	Mesoscale Discussion	SPC	Big Stone, Brown, Chippewa, Cottonwood, Kandiyohi, Lac qui Parle and 12 more	2 hr
Jul 31, 2:23 PM CDT	Mesoscale Discussion	SPC	Anoka, Carver, Chisago, Dakota, Goodhue, Hennepin and 11 more	2 hr
Jul 30, 7:38 PM CDT	Mesoscale Discussion	SPC	Barron, Burnett, Chippewa, Dunn, Eau Claire, Pepin and 6 more	97 min

Nearby

Mesoscale Discussions in Minnesota, 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.