Alert archive / Wisconsin / Mesoscale Discussions in 2011
Mesoscale Discussion 2103
The Storm Prediction Center issued this mesoscale discussion at Sep 3, 2011, 3:40 AM CDT for 12 counties in Wisconsin. It was in force for 95 min.
The area
The outline as issued.
The facts
- Issued
- Sep 3, 2011, 3:40 AM CDT (08:40 UTC)
- Expired
- Sep 3, 2011, 5:15 AM CDT
- In force
- 95 min
- Issued by
- the Storm Prediction Center
Counties Dane County, WI, Green County, WI, Iowa County, WI, Jefferson County, WI, Kenosha County, WI, Lafayette County, WI, Milwaukee County, WI, Racine County, WI, Rock County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI
The radar
The Milwaukee radar (KMKX), 66 km from the middle of the area, began a volume at 08:44 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, 8.7 hours before the alert went out and 169 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
- 1861 J/kg
- Mixed-layer CIN
- -107 J/kg
- Mixed-layer LCL
- 1596 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 87 m²/s²
- 0-3 km storm-relative helicity
- 165 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 3.6
The text
As transmitted, in the capitals the NWS used until 2016.
808
ACUS11 KWNS 030840
SWOMCD
SPC MCD 030840
ILZ000-WIZ000-IAZ000-031015-
MESOSCALE DISCUSSION 2103
NWS STORM PREDICTION CENTER NORMAN OK
0340 AM CDT SAT SEP 03 2011
AREAS AFFECTED...SRN WI AND EXTREME NRN IL
CONCERNING...SEVERE THUNDERSTORM WATCH 824...825...
VALID 030840Z - 031015Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
824...825...CONTINUES.
PRIMARY DAMAGING WIND THREAT SHOULD REMAIN WITH LEADING CONVECTIVE
LINE SEGMENT ACROSS SRN WI CURRENTLY LOCATED NEAR MADISON THROUGH
ABOUT 11Z. SEVERE THREAT ACROSS NERN IA IS BECOMING INCREASINGLY
MARGINAL.
EARLY THIS MORNING A COLD FRONT EXTENDS FROM SRN LOWER MI THROUGH
NRN IL...SRN IA INTO NERN KS. THE WARM SECTOR IS CAPPED TO SURFACE
BASED CONVECTION. HOWEVER...STORMS WILL LIKELY CONTINUE WITHIN ZONE
OF POST FRONTAL ASCENT OVER SRN WI NEXT FEW HOURS. GREATEST THREAT
FOR ISOLATED DAMAGING WIND SHOULD PERSIST WITH LEADING FORWARD
PROPAGATING LINE SEGMENT ACROSS S-CNTRL WI MOVING EAST AT 30 KT
WHERE THE DOWNSTREAM ATMOSPHERE REMAINS MODERATELY UNSTABLE
/1500-2000 J/KG MUCAPE/. FARTHER WEST ACROSS NERN IA INTO SWRN
WI...ACTIVITY HAS BECOME INCREASINGLY ELEVATED ABOVE THE OUTFLOW
FROM THE LEADING STORMS...RESULTING IN A MORE MARGINAL SEVERE
THREAT. SRN EXTENT OF OUTFLOW BOUNDARY IS PROBABLY MORE SHALLOW IN
NRN IL AND REMAINS SKELETAL WHERE PRESENCE OF CAP COULD POTENTIALLY
LIMIT DEVELOPMENT.
..DIAL.. 09/03/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LOT...MKX...DVN...ARX...
LAT...LON 42939040 43358910 43418793 43058752 42418799 42419057
42629097 42939040SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 2, 11:56 PM CDT | Mesoscale Discussion | SPC | Grant, Green, Iowa, Lafayette, Rock | 94 min |
| Sep 3, 12:48 AM CDT | Severe Thunderstorm Watch | SPC | Dane, Grant, Green, Iowa, Jefferson, Kenosha and 6 more | 6 hr |
| Sep 3, 12:24 PM CDT | Mesoscale Discussion | SPC | Kenosha, Racine | 66 min |
Nearby
Mesoscale Discussions in Wisconsin, 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.