Alert archive / Wisconsin / Mesoscale Discussions in 2011
Mesoscale Discussion 396
The Storm Prediction Center issued this mesoscale discussion at Apr 10, 2011, 1:30 PM CDT for 4 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 10, 2011, 1:30 PM CDT (18:30 UTC)
- Expired
- Apr 10, 2011, 3:30 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 70 counties
Allamakee County, IA, Buchanan County, IA, Clayton County, IA, Delaware County, IA, Dubuque County, IA, Fayette County, IA, Howard County, IA, Jackson County, IA, Jones County, IA, Linn County, IA, Winneshiek County, IA, Carroll County, IL, Jo Daviess County, IL, Stephenson County, IL, Chisago County, MN, Fillmore County, MN, Houston County, MN, Olmsted County, MN, Wabasha County, MN, Winona County, MN, Adams County, WI, Barron County, WI, Buffalo County, WI, Calumet County, WI, Chippewa County, WI, Clark County, WI, Columbia County, WI, Crawford County, WI, Dane County, WI, Dodge County, WI, Dunn County, WI, Eau Claire County, WI, Fond du Lac County, WI, Grant County, WI, Green County, WI, Green Lake County, WI, Iowa County, WI, Jackson County, WI, Jefferson County, WI, Juneau County, WI, La Crosse County, WI, Lafayette County, WI, Langlade County, WI, Lincoln County, WI, Marathon County, WI, Marquette County, WI, Menominee County, WI, Monroe County, WI, Oneida County, WI, Outagamie County, WI, Pepin County, WI, Pierce County, WI, Polk County, WI, Portage County, WI, Price County, WI, Richland County, WI, Rock County, WI, Rusk County, WI, Saint Croix County, WI, Sauk County, WI, Sawyer County, WI, Shawano County, WI, Taylor County, WI, Trempealeau County, WI, Vernon County, WI, Washburn County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI, Wood County, WI
The radar
The La Crosse radar (KARX), 71 km from the middle of the area, began a volume at 18:34 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
Green Bay/Straub, WI (KGRB), launched 12:00Z, 6.5 hours before the alert went out and 191 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.
- Mixed-layer CAPE
- 56 J/kg
- Mixed-layer CIN
- -264 J/kg
- Mixed-layer LCL
- 799 m above ground
- 0-6 km bulk shear
- 69 kt
- 0-1 km storm-relative helicity
- 60 m²/s²
- 0-3 km storm-relative helicity
- 91 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted, in the capitals the NWS used until 2016.
958
ACUS11 KWNS 101831
SWOMCD
SPC MCD 101830
WIZ000-ILZ000-IAZ000-MNZ000-102030-
MESOSCALE DISCUSSION 0396
NWS STORM PREDICTION CENTER NORMAN OK
0130 PM CDT SUN APR 10 2011
AREAS AFFECTED...EXTREME SERN MN...NERN IA...NWRN IL AND MUCH OF WI
CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY
VALID 101830Z - 102030Z
OUTBREAK OF SEVERE STORMS IS EXPECTED THIS AFTERNOON...INITIALLY
FROM ERN MN THROUGH NERN IA...THEN SPREADING RAPIDLY EWD THROUGH WI
AND EXTREME NWRN IL. SUPERCELLS WITH STRONG TORNADOES...VERY LARGE
HAIL AND DAMAGING WIND WILL BE THE MAIN THREATS. A TORNADO WATCH
WILL LIKELY BE ISSUED BY 20Z.
THIS AFTERNOON A COLD FRONT EXTENDS FROM A DEEP LOW PRESSURE AREA IN
E-CNTRL MN SSWWD THROUGH SRN MN...NWRN IA INTO SERN NEB WITH A WARM
FRONT FROM THE SURFACE LOW IN E-CNTRL MN THROUGH NRN WI. THE LOW
WILL DEVELOP EWD TO NEAR THE WI BORDER BY 21Z. NEWD ADVECTION OF
HIGHER THETA-E AIR ALONG A STRONG SSWLY LLJ BENEATH EML PLUME /8.5
C/KM LAPSE RATES/ AND DIABATIC WARMING IS RESULTING IN NEWD
DESTABILIZATION WITH TIME. HOWEVER...THE BOUNDARY LAYER REMAINS
CAPPED BY THE WARM EML AS EVIDENCED BY 18Z MINNEAPOLIS SOUNDING.
UPPER JET IS SHIFTING NEWD INTO THE UPPER MS VALLEY. RAPID ACCAS
DEVELOPMENT RECENTLY OBSERVED FROM NERN IA THROUGH SWRN WI IS LIKELY
INDICATIVE OF NEWD EXPANDING ZONE OF AGEOSTROPHIC FORCING WITHIN THE
UPPER JET EXIT REGION. THIS FORCING IN CONJUNCTION WITH FRONTAL
CONVERGENCE WILL LIKELY MAINTAIN A DEEPER ZONE OF ASCENT THAT SHOULD
EVENTUALLY ERODE THE CAP ENOUGH FOR STORMS TO DEVELOP ALONG THE COLD
FRONT FROM ERN MN INTO NERN IA. STORMS WILL LIKELY MAINTAIN DISCRETE
MODES FOR SEVERAL HOURS AND WILL BE EMBEDDED WITHIN STRONG DEEP
LAYER WIND AND VERTICAL SHEAR SUPPORTIVE OF SUPERCELLS. LARGEST
HODOGRAPHS ARE EXPECTED ACROSS CNTRL THROUGH NRN WI WHERE NEAR
SURFACE WINDS SHOULD REMAIN BACKED TO SLY EAST OF THE SURFACE LOW
WITH 0-1 KM STORM RELATIVE HELICITY EXCEEDING 250 M2/S2. STORMS
DEVELOPING WITHIN THIS ENVIRONMENT WILL LIKELY BECOME CAPABLE OF
PRODUCING STRONG TORNADOES...VERY LARGE HAIL AND DAMAGING WIND.
..DIAL.. 04/10/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...GRB...LOT...MKX...DVN...DLH...ARX...MPX...DMX...
LAT...LON 46229080 45298846 44028810 42788874 41958994 42059190
43759253 45569298 46229080SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 10, 5:03 PM CDT | Mesoscale Discussion | SPC | Adams, Hancock, Henderson, Henry, Knox, McDonough and 4 more | 57 min |
| Apr 10, 6:05 PM CDT | Tornado Watch | SPC | Adams, Boone, Brown, Bureau, Calhoun, Carroll and 48 more | 7 hr |
| Apr 9, 7:42 PM CDT | Severe Thunderstorm Watch | SPC | Allamakee, Chickasaw, Floyd, Howard, Mitchell, Winneshiek | 7 hr |
| Apr 9, 9:06 PM CDT | Mesoscale Discussion | SPC | Audubon, Buena Vista, Calhoun, Carroll, Cass, Cherokee and 31 more | 54 min |
| Apr 9, 10:43 PM CDT | Mesoscale Discussion | SPC | Allamakee, Black Hawk, Bremer, Buena Vista, Butler, Cerro Gordo and 25 more | 62 min |
| Apr 9, 11:01 PM CDT | Tornado Watch | SPC | Allamakee, Bremer, Buena Vista, Butler, Cerro Gordo, Cherokee and 19 more | 5 hr |
| Apr 10, 1:26 AM CDT | Mesoscale Discussion | SPC | Allamakee, Buena Vista, Cerro Gordo, Chickasaw, Clay, Dickinson and 14 more | 64 min |
| Apr 10, 3:19 PM CDT | Tornado Watch | SPC | Allamakee, Clayton, Fayette, Howard, Winneshiek | 7 hr |
| Apr 9, 7:47 PM CDT | Severe Thunderstorm Watch | SPC | Cottonwood, Jackson, Lincoln, Lyon, Murray, Nobles and 2 more | 3 hr |
| Apr 10, 6:02 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Calumet, Columbia, Dane, Dodge and 26 more | 88 min |
Nearby
Mesoscale Discussions in Wisconsin, 2011Mesoscale Discussions in Iowa, 2011Mesoscale Discussions in Minnesota, 2011Every 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.