Alert archive / Minnesota / Mesoscale Discussions in 2004

Mesoscale Discussion 620

May 9, 200410 counties in Minnesota; 10 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at May 9, 2004, 3:29 PM CDT for 10 counties in Minnesota; 10 counties in Wisconsin. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued: May 9, 2004, 3:29 PM CDT (20:29 UTC)
Expired: May 9, 2004, 5:00 PM CDT
In force: 91 min
Issued by: the Storm Prediction Center

Counties Chisago County, MN, Dakota County, MN, Goodhue County, MN, Hennepin County, MN, Le Sueur County, MN, Ramsey County, MN, Rice County, MN, Scott County, MN, Wabasha County, MN, Washington County, MN, Buffalo County, WI, Chippewa County, WI, Clark County, WI, Dunn County, WI, Eau Claire County, WI, Pepin County, WI, Pierce County, WI, Polk County, WI, Saint Croix County, WI, Trempealeau County, WI

The radar

The La Crosse radar (KARX), 111 km from the middle of the area, began a volume at 20:28 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.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 8.5 hours before the alert went out and 159 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: 8 J/kg
Mixed-layer CIN: -483 J/kg
Mixed-layer LCL: 802 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 207 m²/s²
0-3 km storm-relative helicity: 170 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 092029
SWOMCD
SPC MCD 092029 
WIZ000-MNZ000-092200-

MESOSCALE DISCUSSION 0620
NWS STORM PREDICTION CENTER NORMAN OK
0329 PM CDT SUN MAY 09 2004

AREAS AFFECTED...SE AND E MN THROUGH  W CNTRL WI

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 092029Z - 092200Z

STORMS ARE EXPECTED TO DEVELOP SEWD THROUGH ERN MN AND W CNTRL WI
INTO THE EVENING. LARGE HAIL AND DAMAGING WIND WILL BE LIKELY.
HOWEVER...AN ISOLATED TORNADO OR TWO WILL ALSO BE POSSIBLE. AN
ADDITIONAL WW WILL BE ISSUED SOON FOR SE MN THROUGH W CNTRL WI.

THIS AFTERNOON THE ATMOSPHERE CONTINUES TO DESTABILIZE ALONG AND S
OF A WARM FRONT/OUTFLOW BOUNDARY FROM WRN WI INTO SE MN. SUPERCELL
STORM OVER S CNTRL MN IS EXPECTED TO CONTINUE ESEWD SUPPORTED BY
LIFT AND MOIST UNSTABLE SWLY INFLOW ALONG AND N OF THE BOUNDARY.
SHORT TERM TRENDS SUGGEST THIS STORM MAY BE EVOLVING INTO A BOW ECHO
AND GIVEN 25F-30F TEMPERATURE-DEWPOINT SPREADS DOWNSTREAM FROM THIS
STORM..THREAT FOR DAMAGING WIND MAY INCREASE. OTHER STORMS MAY ALSO
DEVELOP IN VICINITY OF THE BOUNDARY... ESPECIALLY TOWARD EARLY
EVENING AS THE SWLY LOW LEVEL JET STRENGTHENS.

..DIAL.. 05/09/2004

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

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

44459005 44189205 44369423 45539291 45379173 45119005

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 9, 2:00 PM CDT	Mesoscale Discussion	SPC	Big Stone, Blue Earth, Brown, Carver, Chippewa, Kandiyohi and 19 more	3 hr
May 9, 2:30 PM CDT	Severe Thunderstorm Watch	SPC	Benton, Brown, Chippewa, Cottonwood, Isanti, Kanabec and 22 more	6 hr
May 9, 3:55 PM CDT	Tornado Watch	SPC	Anoka, Blue Earth, Brown, Carver, Dakota, Dodge and 24 more	5 hr
May 9, 4:46 PM CDT	Mesoscale Discussion	SPC	Houston	59 min
May 9, 5:38 PM CDT	Mesoscale Discussion	SPC	Anoka, Blue Earth, Brown, Carver, Chisago, Cottonwood and 25 more	2 hr
May 8, 9:55 PM CDT	Mesoscale Discussion	SPC	Columbia, Dane, Dodge, Green, Iowa, Jefferson and 9 more	2 hr
May 9, 11:48 AM CDT	Mesoscale Discussion	SPC	Columbia, Dane, Dodge, Fond du Lac, Green, Green Lake and 10 more	2 hr
May 9, 12:55 PM CDT	Severe Thunderstorm Watch	SPC	Kenosha, Milwaukee, Ozaukee, Racine, Washington	6 hr
May 9, 2:46 PM CDT	Mesoscale Discussion	SPC	Kenosha, Milwaukee, Ozaukee, Racine	89 min
May 9, 6:15 PM CDT	Severe Thunderstorm Watch	SPC	Ashland, Barron, Bayfield, Douglas, Forest, Iron and 6 more	8 hr

Nearby

Mesoscale Discussions in Minnesota, 2004 Mesoscale Discussions in Wisconsin, 2004 Every mesoscale discussion in 2004

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.