Alert archive / Minnesota / Mesoscale Discussions in 2011

Mesoscale Discussion 714

May 10, 20115 counties in Iowa; 39 counties in Minnesota; 16 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at May 10, 2011, 5:10 PM CDT for 5 counties in Iowa; 39 counties in Minnesota; 16 counties in Wisconsin. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued: May 10, 2011, 5:10 PM CDT (22:10 UTC)
Expired: May 10, 2011, 6:45 PM CDT
In force: 95 min
Issued by: the Storm Prediction Center

All 60 counties

Allamakee County, IA, Howard County, IA, Mitchell County, IA, Winneshiek County, IA, Worth County, IA, Anoka County, MN, Becker County, MN, Benton County, MN, Blue Earth County, MN, Carver County, MN, Chisago County, MN, Crow Wing County, MN, Dakota County, MN, Dodge County, MN, Fillmore County, MN, Freeborn County, MN, Goodhue County, MN, Hennepin County, MN, Houston County, MN, Isanti County, MN, Kanabec County, MN, Le Sueur County, MN, McLeod County, MN, Meeker County, MN, Mille Lacs County, MN, Morrison County, MN, Mower County, MN, Nicollet County, MN, Olmsted County, MN, Otter Tail County, MN, Ramsey County, MN, Rice County, MN, Scott County, MN, Sherburne County, MN, Sibley County, MN, Stearns County, MN, Steele County, MN, Todd County, MN, Wabasha County, MN, Wadena County, MN, Waseca County, MN, Washington County, MN, Winona County, MN, Wright County, MN, Buffalo County, WI, Crawford County, WI, Dunn County, WI, Eau Claire County, WI, Iowa County, WI, Jackson County, WI, La Crosse County, WI, Monroe County, WI, Pepin County, WI, Pierce County, WI, Polk County, WI, Richland County, WI, Saint Croix County, WI, Sauk County, WI, Trempealeau County, WI, Vernon County, WI

The radar

The Minneapolis radar (KMPX), 35 km from the middle of the area, began a volume at 22:10 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.

Tornado Watch 271May 10, 5:55 PM CDT

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 10.2 hours before the alert went out and 37 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: 1366 J/kg
Mixed-layer CIN: -392 J/kg
Mixed-layer LCL: 571 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 119 m²/s²
0-3 km storm-relative helicity: 109 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.0

Open this sounding in Storm Lab

The text

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

653 
ACUS11 KWNS 102211
SWOMCD
SPC MCD 102210
WIZ000-IAZ000-MNZ000-102345-

MESOSCALE DISCUSSION 0714
NWS STORM PREDICTION CENTER NORMAN OK
0510 PM CDT TUE MAY 10 2011

AREAS AFFECTED...CNTRL AND SERN MN...W CNTRL WI...FAR NERN IA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 102210Z - 102345Z

MORE WIDESPREAD THUNDERSTORM DEVELOPMENT MAY OCCUR IN THE NEXT HOUR
OR SO ACROSS CNTRL MN. IF THUNDERSTORMS CAN DEVELOP EXPECT TORNADOES
AND LARGE HAIL TO BE MAIN THREAT AND A TORNADO WATCH WOULD BE
NEEDED. HOWEVER THERE IS QUITE A BIT OF UNCERTAINTY AT THIS TIME AS
TO WHETHER OR NOT MORE THAN A STORM OR TWO WILL BE ABLE TO FORM AND
HOW LONG THE THREAT WOULD LAST GIVEN RATHER NARROW WARM/MOIST SECTOR
AND STRONG CAP.

21Z SFC ANALYSIS INDICATED SFC LOW ACROSS W CNTRL MN WITH A WARM
FRONT EXTENDING E/SEWD ACROSS MN INTO SRN WI AND A COLD FRONT SWD
FROM THE LOW INTO WRN IA AND ERN NEB. LIGHTNING DATA INDICATED
CONVECTIVE INITIATION HAD OCCURRED AND A STORM HAD DEVELOPED IN ERN
OTTER TAIL COUNTY AS OF AROUND 2145Z. A NARROW WINDOW WILL EXIST FOR
STORMS TO DEVELOP AND BECOME ORGANIZED ACROSS SERN MN NEAR THE SFC
LOW/FRONTAL TRIPLE POINT WITH DEW POINTS IN THE MID 60S TO LOW 70S.
THE QUALITY OF THE AIR MASS QUICKLY DEGRADES EWD INTO WI/E OF THE
WARM FRONT. THAT BEING SAID...MLCAPE VALUES FROM NEAR 2000 J/KG
ACROSS CNTRL MN TO NEAR 5000 J/KG ACROSS SERN MN WILL MORE THAN
SUPPORT VIGOROUS UPDRAFTS SHOULD CAPPING CONTINUE TO ERODE.
ADDITIONALLY...EFFECTIVE BULK SHEAR VALUES OF 50-60 KT AND MID LEVEL
LAPSE RATES OF 8-9 DEG C WILL SUPPORT SUPERCELL STRUCTURES CAPABLE
OF PRODUCING LARGE HAIL.

IF ROBUST STORM DEVELOPMENT DOES OCCUR A WATCH COULD BE NEEDED SOON.

..STOPPKOTTE.. 05/10/2011

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

ATTN...WFO...MKX...DLH...ARX...MPX...DMX...FGF...

LAT...LON   47029598 47089563 46939501 46709433 46319360 45719258
            44739119 43788993 43248942 43008942 42908955 42949040
            43049159 43259276 43399356 43499380 44309435 45629518
            46459579 46739594 47029598

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 10, 1:56 AM CDT	Mesoscale Discussion	SPC	Wilkin	94 min
May 10, 5:53 PM CDT	Tornado Watch	SPC	Aitkin, Anoka, Benton, Carlton, Carver, Cass and 18 more	6 hr

Nearby

Mesoscale Discussions in Minnesota, 2011 Mesoscale Discussions in Wisconsin, 2011 Mesoscale Discussions in Iowa, 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.