Alert archive / Illinois / Mesoscale Discussions in 2011

Mesoscale Discussion 334

April 3, 201116 counties in Illinois; 5 counties in Iowa; 13 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Apr 3, 2011, 10:23 PM CDT for 16 counties in Illinois; 5 counties in Iowa; 13 counties in Wisconsin. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued: Apr 3, 2011, 10:23 PM CDT (03:23 UTC)
Expired: Apr 3, 2011, 11:30 PM CDT
In force: 67 min
Issued by: the Storm Prediction Center

All 34 counties

Clinton County, IA, Jackson County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Boone County, IL, Carroll County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Jo Daviess County, IL, Kane County, IL, Kendall County, IL, Lake County, IL, Lee County, IL, McHenry County, IL, Ogle County, IL, Rock Island County, IL, Stephenson County, IL, Whiteside County, IL, Winnebago County, IL, Columbia County, WI, Dane County, WI, Dodge County, WI, Green 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), 100 km from the middle of the area, began a volume at 03:24 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, 3.4 hours before the alert went out and 125 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: 1790 J/kg
Mixed-layer CIN: -85 J/kg
Mixed-layer LCL: 1684 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 119 m²/s²
0-3 km storm-relative helicity: 168 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 5.9

Open this sounding in Storm Lab

The text

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

146 
ACUS11 KWNS 040324
SWOMCD
SPC MCD 040323
ILZ000-WIZ000-IAZ000-040430-

MESOSCALE DISCUSSION 0334
NWS STORM PREDICTION CENTER NORMAN OK
1023 PM CDT SUN APR 03 2011

AREAS AFFECTED...SRN WI...ERN IA...NRN IL

CONCERNING...SEVERE THUNDERSTORM WATCH 86...

VALID 040323Z - 040430Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 86
CONTINUES.

03Z ANALYSIS PLACED COLD FRONT FROM KMKE-KRFD-NERN MO.  CONSIDERABLE
ELEVATED TSTMS HAVE FORMED FROM ERN IA INTO SRN WI WEST OF THE COLD
FRONT AS ANAFRONTAL SITUATION DEVELOPS WITH THE APPROACHING UPPER
TROUGH. MID-LEVEL LAPSE RATES RANGING FROM 6.5-8.5 DEG C PER KM
EXISTS ACROSS THE REGION AND LARGE HAIL WILL BE LIKELY WITH THESE
STORMS THROUGH EARLY MORNING MONDAY.

MEANWHILE...TSTMS APPROACHING THE CHICAGOLAND MAY BE MORE SFC-BASED
AND GIVEN DAVENPORT VWP SHOWING 50 KTS OF WSW FLOW AT HALF OF A
KILOMETER AGL...DAMAGING WINDS ARE NOT OUT OF THE QUESTION IN
CHICAGO METRO FROM 0330-05Z.  OTHERWISE...LARGE HAIL WILL ALSO BE
LIKELY.

..RACY.. 04/04/2011

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

ATTN...WFO...LOT...MKX...DVN...ARX...

LAT...LON   41619118 43388972 43748842 43318743 42548742 41718768
            41418820 41708958 41189138 41619118

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 3, 7:44 PM CDT	Mesoscale Discussion	SPC	Boone, Bureau, Carroll, Fulton, Hancock, Henderson and 16 more	61 min
Apr 3, 8:11 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Brown, Calhoun, Cass, Fulton, Greene and 12 more	6 hr
Apr 3, 8:54 PM CDT	Severe Thunderstorm Watch	SPC	Boone, Cook, DeKalb, DuPage, Grundy, Kane and 9 more	5 hr
Apr 3, 10:50 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Cass, Fulton, Hancock, McDonough and 4 more	85 min
Apr 4, 1:29 AM CDT	Mesoscale Discussion	SPC	Adams, Bond, Brown, Calhoun, Cass, Christian and 31 more	91 min
Apr 4, 1:53 AM CDT	Mesoscale Discussion	SPC	Cook, DuPage, Grundy, Kane, Kendall, Lake and 2 more	97 min
Apr 4, 4:20 AM CDT	Mesoscale Discussion	SPC	Clark, Clay, Crawford, Effingham, Jasper, Lawrence and 2 more	25 min
Apr 4, 6:53 AM CDT	Mesoscale Discussion	SPC	Hardin, Lawrence, Wabash	2 hr
Apr 4, 7:22 AM CDT	Tornado Watch	SPC	Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more	7 hr

Nearby

Mesoscale Discussions in Illinois, 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.