Alert archive / Iowa / Mesoscale Discussions in 2011
Mesoscale Discussion 330
The Storm Prediction Center issued this mesoscale discussion at Apr 3, 2011, 7:44 PM CDT for 22 counties in Illinois; 27 counties in Iowa; 4 counties in Missouri. It was in force for 61 min.
The area
The outline as issued.
The facts
- Issued
- Apr 3, 2011, 7:44 PM CDT (00:44 UTC)
- Expired
- Apr 3, 2011, 8:45 PM CDT
- In force
- 61 min
- Issued by
- the Storm Prediction Center
All 53 counties
Appanoose County, IA, Benton County, IA, Cedar County, IA, Clinton County, IA, Davis County, IA, Delaware County, IA, Des Moines County, IA, Dubuque County, IA, Henry County, IA, Iowa County, IA, Jackson County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Mahaska County, IA, Monroe County, IA, Muscatine County, IA, Poweshiek County, IA, Scott County, IA, Van Buren County, IA, Wapello County, IA, Washington County, IA, Wayne County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, Fulton County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, Knox County, IL, Lee County, IL, Marshall County, IL, McDonough County, IL, Mercer County, IL, Ogle County, IL, Peoria County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Stephenson County, IL, Warren County, IL, Whiteside County, IL, Winnebago County, IL, Clark County, MO, Putnam County, MO, Schuyler County, MO, Scotland County, MO
The radar
The Quad Cities radar (KDVN), 54 km from the middle of the area, began a volume at 00:47 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
Davenport, (KDVN), launched 00:00Z, 0.7 hours before the alert went out and 60 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
- 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
The text
As transmitted, in the capitals the NWS used until 2016.
156
ACUS11 KWNS 040045
SWOMCD
SPC MCD 040044
ILZ000-WIZ000-IAZ000-MOZ000-040145-
MESOSCALE DISCUSSION 0330
NWS STORM PREDICTION CENTER NORMAN OK
0744 PM CDT SUN APR 03 2011
AREAS AFFECTED...FAR NERN MO...ERN IA...NWRN IL...FAR SRN WI
CONCERNING...TORNADO WATCH 82...
VALID 040044Z - 040145Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 82 CONTINUES.
SURFACE LOW PRESSURE AND SWWD TRAILING COLD FRONT EXTEND ALONG A
LINE FROM 20 WSW OF DBQ TO 30 NW OF IRK AT 0030Z...AND HAVE FOCUSED
THE DEVELOPMENT OF A BROKEN LINE OF SEMI-DISCRETE THUNDERSTORMS
DURING THE LAST HR OR SO...WHICH HAVE DISPLAYED SUPERCELL
CHARACTERISTICS. OBSERVED 00Z RAOB FROM DVN INDICATED THE PRESENCE
OF VERY STEEP MIDLEVEL LAPSE RATES /AOA 8.5 C PER KM IN THE 700-500
MB LAYER/ AND STRONG DEEP LAYER VERTICAL WIND SHEAR /0-6 KM BULK
SHEAR IN EXCESS OF 40 KT/...WHICH WILL CONTINUE TO SUPPORT A THREAT
FOR LARGE HAIL /POSSIBLY ISOLATED SIG HAIL/ DURING THE EVENING. IN
ADDITION...ZONE OF LOWER SURFACE DEWPOINT DEPRESSIONS...BACKED
LOW-LEVEL WINDS...AND ENHANCED 0-1 KM SRH /AOA 300 M2 S-2 PER SFCOA
GUIDANCE/ EXISTS ALONG E-W ORIENTED WARM FRONT OVER ERN IA INTO NWRN
IL...AND MAY FOCUS HIGHEST TORNADO THREAT AS STORMS MOVE NEWD ACROSS
THE BOUNDARY.
FARTHER S OVER NERN MO AND WRN IL...STORM COVERAGE IS EXPECTED TO
INCREASE DURING THE NIGHT AS COLD FRONT MOVES INTO THE REGION.
STRONG INSTABILITY AND VERTICAL WIND SHEAR WILL PERSIST ALONG THE
BOUNDARY...AND MAY FAVOR A THREAT FOR DAMAGING WINDS AND LARGE HAIL.
AS A RESULT...AN ADDITIONAL WW MAY BE NEEDED SOON S OF WW 82 AND E
OF WW 83.
..GARNER.. 04/04/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LOT...ILX...MKX...LSX...DVN...ARX...DMX...EAX...
LAT...LON 42599169 42598845 41148915 40249044 40199095 40299234
40499363 42599169SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| 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, 10:23 PM CDT | Mesoscale Discussion | SPC | Boone, Carroll, Cook, DeKalb, DuPage, Jo Daviess and 10 more | 67 min |
| 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 |
| Apr 3, 7:26 PM CDT | Mesoscale Discussion | SPC | Adair, Andrew, Buchanan, Caldwell, Carroll, Chariton and 16 more | 64 min |
| Apr 3, 8:15 PM CDT | Mesoscale Discussion | SPC | Adair, Andrew, Barton, Bates, Buchanan, Caldwell and 22 more | 60 min |
| Apr 3, 8:33 PM CDT | Severe Thunderstorm Watch | SPC | Barton, Benton, Camden, Cedar, Dade, Hickory and 5 more | 5 hr |
| Apr 3, 9:51 PM CDT | Mesoscale Discussion | SPC | Barry, McDonald, Newton | 84 min |
| Apr 3, 11:02 PM CDT | Mesoscale Discussion | SPC | Barton, Camden, Cedar, Dade, Dallas, Greene and 10 more | 88 min |
| Apr 4, 5:48 AM CDT | Mesoscale Discussion | SPC | Oregon, Ripley | 117 min |
Nearby
Mesoscale Discussions in Iowa, 2011Mesoscale Discussions in Illinois, 2011Mesoscale Discussions in Missouri, 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.