Alert archive / Minnesota / Mesoscale Discussions in 2012

Mesoscale Discussion 668

May 2, 201216 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at May 2, 2012, 9:18 PM CDT for 16 counties in Minnesota. It was in force for 27 min.

The area

The outline as issued.

The facts

Issued
May 2, 2012, 9:18 PM CDT (02:18 UTC)
Expired
May 2, 2012, 9:45 PM CDT
In force
27 min
Issued by
the Storm Prediction Center

Counties Blue Earth County, MN, Brown County, MN, Cottonwood County, MN, Faribault County, MN, Freeborn County, MN, Goodhue County, MN, Jackson County, MN, Le Sueur County, MN, Martin County, MN, Murray County, MN, Nicollet County, MN, Nobles County, MN, Rice County, MN, Steele County, MN, Waseca County, MN, Watonwan County, MN

The radar

The Minneapolis radar (KMPX), 96 km from the middle of the area, began a volume at 02:18 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, 2.3 hours before the alert went out and 95 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, Minneapolis, MN at 00:00Z on 2012-05-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 84 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, Minneapolis, MN at 00:00Z on 2012-05-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 21 square meters per square second.1939587897Sfc1 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
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.

281 
ACUS11 KWNS 030218
SWOMCD
SPC MCD 030218 
MNZ000-WIZ000-IAZ000-030245-

MESOSCALE DISCUSSION 0668
NWS STORM PREDICTION CENTER NORMAN OK
0918 PM CDT WED MAY 02 2012

AREAS AFFECTED...PARTS OF SOUTH CENTRAL AND SWRN MN

CONCERNING...SEVERE THUNDERSTORM WATCH 225...

VALID 030218Z - 030245Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 225
CONTINUES.

SUMMARY...WW 225 MAY BE CANCELLED WELL BEFORE THE SCHEDULED 04Z
EXPIRATION TIME.  ADDITIONAL STORMS MAY AFFECT THE NWRN-NRN EXTENT
OF THIS WW AS ACTIVITY FROM NERN SD ADVANCES EWD.  HOWEVER...THAT
POTENTIAL WOULD NOT OCCUR UNTIL AFTER 04Z.

DISCUSSION...REGIONAL RADAR TRENDS THIS EVENING INDICATED A STORM
MOVING EWD AND EXITING GOODHUE COUNTY MN INTO WW 227.  THE AIR MASS
IN THE WAKE OF THIS STORM AND ADDITIONAL ACTIVITY AFFECTING SERN MN
INTO ADJACENT BUFFALO COUNTY WI HAS BEEN CONVECTIVELY
OVERTURNED/STABILIZED.  IN ADDITION TO THIS LIMITING FACTOR TO
SUPPORT NEW TSTM DEVELOPMENT WWD ACROSS WW 225...LOW LEVEL
CONVERGENCE IS LACKING...LIKELY DUE TO LOW LEVEL DIFLUENT FLOW
REGIME OVER NWRN IA INTO SWRN-SOUTH CENTRAL MN PER REGIONAL VWP
DATA.

..PETERS.. 05/03/2012

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

ATTN...WFO...ARX...MPX...DMX...FSD...

LAT...LON   44209624 44549380 44559234 44279263 44119310 43489309
            43509604 44209624

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, 11:06 PM CDTMesoscale DiscussionSPCAnoka, Big Stone, Carver, Chippewa, Dakota, Hennepin and 17 more24 min
May 3, 8:43 AM CDTMesoscale DiscussionSPCDakota, Dodge, Goodhue, Olmsted, Rice, Steele and 2 more92 min

Nearby

Mesoscale 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.