Alert archive / Iowa / Mesoscale Discussions in 2004
Mesoscale Discussion 992
The Storm Prediction Center issued this mesoscale discussion at May 30, 2004, 12:13 PM CDT for 4 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 30, 2004, 12:13 PM CDT (17:13 UTC)
- Expired
- May 30, 2004, 2:15 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 34 counties
Cedar County, IA, Clayton County, IA, Clinton 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, Muscatine County, IA, Scott County, IA, Van Buren County, IA, Washington County, IA, Carroll County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, Knox County, IL, Mercer County, IL, Rock Island County, IL, Warren County, IL, Whiteside County, IL, Clark County, MO, Crawford County, WI, Grant County, WI, Lafayette County, WI
The radar
The Quad Cities radar (KDVN), 43 km from the middle of the area, began a volume at 17:15 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
Lincoln, IL (KILX), launched 12:00Z, 5.2 hours before the alert went out and 275 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
- 1629 J/kg
- Mixed-layer CIN
- -53 J/kg
- Mixed-layer LCL
- 569 m above ground
- 0-6 km bulk shear
- 46 kt
- 0-1 km storm-relative helicity
- 201 m²/s²
- 0-3 km storm-relative helicity
- 177 m²/s²
- Significant tornado parameter
- 1.4
- Supercell composite
- 8.9
The text
As transmitted, in the capitals the NWS used until 2016.
444 ACUS11 KWNS 301714 SWOMCD SPC MCD 301713 ILZ000-WIZ000-IAZ000-MOZ000-301915- MESOSCALE DISCUSSION 0992 NWS STORM PREDICTION CENTER NORMAN OK 1213 PM CDT SUN MAY 30 2004 AREAS AFFECTED...ERN IA...PARTS OF NW IL...SW WI CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 301713Z - 301915Z RISK OF SUPERCELLS AND POTENTIAL FOR TORNADOES IS INCREASING ACROSS EASTERN IOWA/NORTHWEST ILLINOIS. STRONGER 2 HOUR SURFACE PRESSURE FALLS ALONG THE MISSISSIPPI RIVER...CENTERED NEAR DUBUQUE AT 16Z...HAVE DEVELOPED AHEAD OF SURFACE WAVE EVOLVING NEAR OUTFLOW/COLD FRONT INTERSECTION NOW WEST SOUTHWEST OF KIRKSVILLE. THIS WAVE WILL CONTINUE NORTHEASTWARD NEXT FEW HOURS...AS EXIT REGION OF CYCLONIC POLAR JET STREAK NOSES ACROSS NORTH/CENTRAL MISSOURI. AXIS OF STRONGEST DESTABILIZATION WILL OCCUR ALONG THE EASTERN IOWA BORDER/MISSISSIPPI RIVER THROUGH 21Z...AND WILL BECOME FOCUS FOR INTENSE CONVECTIVE DEVELOPMENT. SUPERCELL NEAR SURFACE WAVE HAS ALREADY PRODUCED TORNADOES...AND MAY CONTINUE ACROSS THE KIRKSVILLE AREA INTO SOUTHEAST IOWA THROUGH THE MID AFTERNOON HOURS. MAIN TORNADO THREAT WILL REMAIN WITH LONG-LIVED MESOCYCLONE ASSOCIATED WITH THIS ACTIVITY. ADDITIONAL SUPERCELLS ARE LIKELY TO FORM. ..KERR.. 05/30/2004 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LOT...ILX...MKX...LSX...DVN...ARX...DMX... 42879164 43409090 42828990 41908952 40869016 40209111 40439194 40939240
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 30, 7:40 AM CDT | Tornado Watch | SPC | Adams, Brown, Cass, Champaign, Christian, Coles and 31 more | 5 hr |
| May 30, 9:40 AM CDT | Mesoscale Discussion | SPC | Adams, Brown, Calhoun, Cass, Greene, Hancock and 6 more | 3 hr |
| May 30, 10:04 AM CDT | Mesoscale Discussion | SPC | Alexander, Clay, Clinton, Edwards, Franklin, Gallatin and 19 more | 2 hr |
| May 30, 10:50 AM CDT | Tornado Watch | SPC | Adams, Brown, Hancock, McDonough, Pike | 8 hr |
| May 30, 11:04 AM CDT | Mesoscale Discussion | SPC | Champaign, Cook, DeWitt, Douglas, DuPage, Iroquois and 4 more | 116 min |
| May 30, 11:50 AM CDT | Tornado Watch | SPC | Clark, Crawford, Edgar, Edwards, Gallatin, Hardin and 7 more | 7 hr |
| May 30, 12:25 PM CDT | Tornado Watch | SPC | Bureau, Carroll, Henderson, Henry, Jo Daviess, Knox and 8 more | 7 hr |
| May 30, 12:53 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Calhoun, Cass, Christian, Fulton and 13 more | 2 hr |
| May 30, 1:05 PM CDT | Tornado Watch | SPC | Alexander, Bond, Calhoun, Cass, Champaign, Christian and 45 more | 6 hr |
| May 30, 3:16 PM CDT | Mesoscale Discussion | SPC | Boone, Bureau, Carroll, Cass, DeKalb, DuPage and 29 more | 119 min |
| May 30, 4:25 PM CDT | Tornado Watch | SPC | Boone, Cook, DeKalb, DuPage, Grundy, Iroquois and 12 more | 6 hr |
| May 30, 5:10 PM CDT | Mesoscale Discussion | SPC | Alexander, Bond, Clinton, Fayette, Jackson, Madison and 7 more | 95 min |
| May 30, 5:36 PM CDT | Mesoscale Discussion | SPC | Boone, Bureau, Carroll, Cass, Champaign, Christian and 39 more | 54 min |
| May 30, 6:40 PM CDT | Tornado Watch | SPC | Alexander, Bond, Champaign, Christian, Clark, Clay and 41 more | 6 hr |
| May 30, 6:55 PM CDT | Tornado Watch | SPC | Gallatin, Hardin, Lawrence, Wabash | 8 hr |
| May 29, 8:45 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Audubon, Carroll, Cass, Crawford and 15 more | 60 min |
| May 29, 9:21 PM CDT | Mesoscale Discussion | SPC | Buena Vista, Calhoun, Cherokee, Clay, Dickinson, Emmet and 13 more | 54 min |
| May 29, 9:35 PM CDT | Tornado Watch | SPC | Adair, Adams, Audubon, Boone, Carroll, Cass and 26 more | 6 hr |
| May 29, 11:23 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Audubon, Carroll, Cass, Crawford and 13 more | 67 min |
| May 30, 2:38 AM CDT | Mesoscale Discussion | SPC | Appanoose, Clarke, Davis, Decatur, Jasper, Keokuk and 13 more | 97 min |
| May 30, 2:44 PM CDT | Mesoscale Discussion | SPC | Bollinger, Butler, Cape Girardeau, Carter, Christian, Crawford and 26 more | 2 hr |
| May 30, 3:20 PM CDT | Tornado Watch | SPC | Dunklin, New Madrid, Pemiscot, Ripley | 8 hr |
| May 30, 2:45 PM CDT | Mesoscale Discussion | SPC | Buffalo, Dunn, La Crosse, Pepin, Pierce, Saint Croix and 2 more | 2 hr |
Nearby
Mesoscale Discussions in Iowa, 2004Mesoscale Discussions in Illinois, 2004Mesoscale Discussions in Wisconsin, 2004Every mesoscale discussion in 2004
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.