Alert archive / Minnesota / Mesoscale Discussions in 2005

Mesoscale Discussion 2139

September 3, 200522 counties in Iowa; 46 counties in Minnesota; 10 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Sep 3, 2005, 11:18 PM CDT for 22 counties in Iowa; 46 counties in Minnesota; 10 counties in Wisconsin. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued: Sep 3, 2005, 11:18 PM CDT (04:18 UTC)
Expired: Sep 4, 2005, 12:45 AM CDT
In force: 87 min
Issued by: the Storm Prediction Center

All 78 counties

Allamakee County, IA, Bremer County, IA, Butler County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Clay County, IA, Clayton County, IA, Dickinson County, IA, Emmet County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Hancock County, IA, Howard County, IA, Humboldt County, IA, Kossuth County, IA, Mitchell County, IA, Palo Alto County, IA, Winnebago County, IA, Winneshiek County, IA, Worth County, IA, Wright County, IA, Anoka County, MN, Blue Earth County, MN, Brown County, MN, Carver County, MN, Chippewa County, MN, Cottonwood County, MN, Dakota County, MN, Dodge County, MN, Douglas County, MN, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Goodhue County, MN, Grant County, MN, Hennepin County, MN, Houston County, MN, Jackson County, MN, Kandiyohi County, MN, Le Sueur County, MN, Lyon County, MN, Martin County, MN, McLeod County, MN, Meeker County, MN, Mower County, MN, Murray County, MN, Nicollet County, MN, Olmsted County, MN, Pope County, MN, Ramsey County, MN, Redwood County, MN, Renville County, MN, Rice County, MN, Scott County, MN, Sherburne County, MN, Sibley County, MN, Stearns County, MN, Steele County, MN, Stevens County, MN, Swift County, MN, Wabasha County, MN, Waseca County, MN, Washington County, MN, Watonwan County, MN, Winona County, MN, Wright County, MN, Yellow Medicine County, MN, Buffalo County, WI, Crawford County, WI, Dunn County, WI, Eau Claire County, WI, Jackson County, WI, La Crosse County, WI, Pepin County, WI, Pierce County, WI, Saint Croix County, WI, Trempealeau County, WI

The radar

The Minneapolis radar (KMPX), 128 km from the middle of the area, began a volume at 04:21 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

Davenport, (KDVN), launched 00:00Z, 4.3 hours before the alert went out and 328 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: 12 J/kg
Mixed-layer CIN: -158 J/kg
Mixed-layer LCL: 2071 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 59 m²/s²
0-3 km storm-relative helicity: 137 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 040418
SWOMCD
SPC MCD 040418 
WIZ000-IAZ000-MNZ000-040545-

MESOSCALE DISCUSSION 2139
NWS STORM PREDICTION CENTER NORMAN OK
1118 PM CDT SAT SEP 03 2005

AREAS AFFECTED...SRN MN...WRN WI...NRN IA

CONCERNING...SEVERE THUNDERSTORM WATCH 766...

VALID 040418Z - 040545Z

A SEVERE MCS WITH LARGE HAIL AND DAMAGING WINDS MAY BE MAINTAINED
INTO NRN IA OVER THE NEXT FEW HOURS AS VEERING LOW LEVEL JET
PROMOTES STRONG ASCENT AND DESTABILIZATION ON THE EDGE OF PLAINS
CAPPING INVERSION/INSTABILITY GRADIENT. A NEW WATCH MAY BE NEEDED TO
THE SOUTH OF WW 766.

MCS HAS MATURED AND ACQUIRED A MORE LINEAR STRUCTURE OVER THE PAST
COUPLE OF HOURS ACROSS SRN/SERN MN. SUPERCELL STRUCTURES ARE STILL
EVIDENT AND EMBEDDED WITHIN THIS LINE OF INTENSE CONVECTION BUT A
MESOSCALE BOWING STRUCTURE NOW APPEARS TO BE TAKING SHAPE ACROSS
WASECA...STEELE...AND DODGE COUNTIES IN SERN MN. CLASSIC SUMMER MCS
PATTERN PERSISTS OVER SRN MN WITH PRONOUNCED DIRECTIONAL SHEAR
OCCURRING BETWEEN LOW AND MID LEVEL WIND FLOWS...AND VERY STRONG
INSTABILITY FUELING REGENERATIVE CONVECTION ALONG THE WRN FLANK OF
THE CONVECTIVE LINE. MCS MOTION AS A RESULT OF STEERING FLOW AND
PROPAGATION IS ALMOST DUE SOUTH WHICH SHOULD BRING SEVERE POTENTIAL
INTO PARTS OF NRN IA OVER THE NEXT FEW HOURS.

..CARBIN.. 09/04/2005

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

ATTN...WFO...ARX...MPX...DMX...FGF...FSD...ABR...

42819097 42669228 42689394 42989532 44759617 46459617
44569076

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 3, 8:35 PM CDT	Severe Thunderstorm Watch	SPC	Allamakee, Winneshiek	7 hr
Sep 3, 9:21 PM CDT	Mesoscale Discussion	SPC	Allamakee, Winneshiek	114 min
Sep 4, 2:12 AM CDT	Mesoscale Discussion	SPC	Allamakee, Winneshiek	2 hr

Nearby

Mesoscale Discussions in Minnesota, 2005 Mesoscale Discussions in Iowa, 2005 Mesoscale Discussions in Wisconsin, 2005 Every mesoscale discussion in 2005

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.