Alert archive / Iowa / Mesoscale Discussions in 2004
Mesoscale Discussion 1521
The Storm Prediction Center issued this mesoscale discussion at Jul 5, 2004, 3:00 PM CDT for 9 counties in Illinois; 28 counties in Iowa; 12 counties in Missouri. It was in force for 60 min.
The area
The outline as issued.
The facts
- Issued
- Jul 5, 2004, 3:00 PM CDT (20:00 UTC)
- Expired
- Jul 5, 2004, 4:00 PM CDT
- In force
- 60 min
- Issued by
- the Storm Prediction Center
All 49 counties
Appanoose County, IA, Clarke County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Des Moines County, IA, Henry County, IA, Iowa County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Keokuk County, IA, Lee County, IA, Louisa County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Monroe County, IA, Muscatine County, IA, Polk County, IA, Poweshiek County, IA, Scott County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Adams County, IL, Brown County, IL, Hancock County, IL, Henderson County, IL, McDonough County, IL, Mercer County, IL, Rock Island County, IL, Schuyler County, IL, Warren County, IL, Adair County, MO, Clark County, MO, Knox County, MO, Lewis County, MO, Macon County, MO, Marion County, MO, Mercer County, MO, Putnam County, MO, Schuyler County, MO, Scotland County, MO, Shelby County, MO, Sullivan County, MO
The radar
The Des Moines radar (KDMX), 143 km from the middle of the area, began a volume at 20:01 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 12:00Z, 8.0 hours before the alert went out and 188 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
- 477 J/kg
- Mixed-layer CIN
- -177 J/kg
- Mixed-layer LCL
- 1211 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 12 m²/s²
- 0-3 km storm-relative helicity
- 81 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
148 ACUS11 KWNS 052000 SWOMCD SPC MCD 052000 ILZ000-IAZ000-MOZ000-052100- MESOSCALE DISCUSSION 1521 NWS STORM PREDICTION CENTER NORMAN OK 0300 PM CDT MON JUL 05 2004 AREAS AFFECTED...SERN IA/NERN MO INTO WEST CENTRAL IL CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 052000Z - 052100Z PORTIONS OF SERN IA/NERN MO INTO WEST CENTRAL IL ARE BEING MONITORED FOR AN INCREASE IN THUNDERSTORM ACTIVITY...AND THE POTENTIAL FOR A WW. 19Z SURFACE ANALYSIS SHOWED A LOW OVER SWRN IA...JUST W OF DSM... WITH A BOUNDARY EXTENDING EWD INTO CENTRAL IL TO THE N OF PIA. REGIONAL RADARS SHOW A GRADUAL INCREASE IN CONVECTIVE ACTIVITY ALONG AND JUST EAST OF THE SURFACE LOW. AIR MASS ACROSS THE AREA OF CONCERN HAS BEEN SLOW TO DESTABILIZE /MLCAPE AROUND 1000 J/KG/... DESPITE SURFACE DEWPOINTS IN THE UPPER 60S TO LOWER 70S. THIS APPEARS TO BE THE RESULT OF WEAK SHORT WAVE RIDGING AT MID-LEVELS WITH A POCKET OF WARM 500 MB TEMPERATURES AROUND -8 C/KM. HOWEVER...AN INCREASE IN THUNDERSTORM ACTIVITY IS EXPECTED BY LATE AFTERNOON AS COOLER MID-LEVEL TEMPERATURES AND STRONGER UVVS WITH A WELL-DEFINED SHORT WAVE TROUGH...EXTENDING FROM WRN IA TO ERN KS...SPREAD EWD OVER SRN IA/NRN MO TO WRN IL. INCREASING DEEP LAYER SHEAR COMBINED WITH MODERATE INSTABILITY WILL SUPPORT HAIL AND DAMAGING WINDS...WHILE BACKED LOW-LEVEL FLOW ALONG THE SURFACE BOUNDARY SHOULD ALLOW FOR A TORNADO THREAT. ..PETERS.. 07/05/2004 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ILX...LSX...DVN...DMX...EAX... 40509391 41839409 41889210 41619021 39869042 39689278
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 5, 6:55 AM CDT | Severe Thunderstorm Watch | SPC | Bond, Calhoun, Christian, Clinton, Coles, Cumberland and 12 more | 4 hr |
| Jul 5, 9:12 AM CDT | Mesoscale Discussion | SPC | Bond, Calhoun, Christian, Clark, Clay, Clinton and 34 more | 63 min |
| Jul 5, 9:45 AM CDT | Severe Thunderstorm Watch | SPC | Clay, Edwards, Franklin, Gallatin, Hamilton, Jackson and 8 more | 4 hr |
| Jul 5, 12:08 PM CDT | Mesoscale Discussion | SPC | Edwards, Hardin, Lawrence, Richland, Wabash | 67 min |
| Jul 5, 3:43 PM CDT | Mesoscale Discussion | SPC | Bond, Calhoun, Clinton, Jackson, Jersey, Madison and 5 more | 92 min |
| Jul 5, 4:00 PM CDT | Tornado Watch | SPC | Adams, Brown, Calhoun, Cass, Fulton, Greene and 15 more | 6 hr |
| Jul 5, 4:20 PM CDT | Tornado Watch | SPC | Bureau, Carroll, Henderson, Henry, Jo Daviess, Knox and 9 more | 6 hr |
| Jul 5, 6:30 PM CDT | Mesoscale Discussion | SPC | Bureau, Carroll, Henry, Jo Daviess, Mercer, Rock Island and 1 more | 60 min |
| Jul 4, 11:05 PM CDT | Severe Thunderstorm Watch | SPC | Fremont, Mills | 5 hr |
| Jul 5, 1:16 AM CDT | Mesoscale Discussion | SPC | Adair, Adams, Audubon, Boone, Buena Vista, Calhoun and 25 more | 89 min |
| Jul 5, 2:00 AM CDT | Severe Thunderstorm Watch | SPC | Adair, Adams, Appanoose, Audubon, Boone, Calhoun and 31 more | 5 hr |
| Jul 5, 4:45 AM CDT | Mesoscale Discussion | SPC | Adair, Adams, Appanoose, Audubon, Boone, Buena Vista and 30 more | 2 hr |
| Jul 5, 3:25 AM CDT | Severe Thunderstorm Watch | SPC | Barry, Barton, Bates, Benton, Camden, Cedar and 27 more | 6 hr |
| Jul 5, 6:02 AM CDT | Mesoscale Discussion | SPC | Barry, Barton, Bates, Benton, Camden, Cedar and 32 more | 88 min |
Nearby
Mesoscale Discussions in Iowa, 2004Mesoscale Discussions in Missouri, 2004Mesoscale Discussions in Illinois, 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.