Alert archive / Iowa / Mesoscale Discussions in 2004
Mesoscale Discussion 2124
The Storm Prediction Center issued this mesoscale discussion at Aug 26, 2004, 9:13 PM CDT for 4 states. It was in force for 62 min.
The area
The outline as issued.
The facts
- Issued
- Aug 26, 2004, 9:13 PM CDT (02:13 UTC)
- Expired
- Aug 26, 2004, 10:15 PM CDT
- In force
- 62 min
- Issued by
- the Storm Prediction Center
All 78 counties
Allamakee County, IA, Appanoose County, IA, Benton County, IA, Black Hawk County, IA, Bremer County, IA, Buchanan County, IA, Cedar County, IA, Clarke County, IA, Clayton County, IA, Clinton County, IA, Davis County, IA, Decatur County, IA, Delaware County, IA, Dubuque County, IA, Fayette County, IA, Grundy County, IA, Henry County, IA, Iowa County, IA, Jackson County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Linn County, IA, Louisa County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Muscatine County, IA, Polk County, IA, Poweshiek County, IA, Ringgold County, IA, Scott County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Carroll County, IL, Jo Daviess County, IL, Rock Island County, IL, Stephenson County, IL, Adair County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Knox County, MO, Mercer County, MO, Nodaway County, MO, Putnam County, MO, Schuyler County, MO, Scotland County, MO, Sullivan County, MO, Worth County, MO, Columbia County, WI, Crawford County, WI, Dane County, WI, Dodge County, WI, Fond du Lac County, WI, Grant County, WI, Green County, WI, Green Lake County, WI, Iowa County, WI, Jefferson County, WI, Lafayette County, WI, Marquette County, WI, Richland County, WI, Rock County, WI, Sauk County, WI, Vernon County, WI, Washington County, WI
The radar
The Des Moines radar (KDMX), 108 km from the middle of the area, began a volume at 02:14 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, 2.2 hours before the alert went out and 161 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
- 3587 J/kg
- Mixed-layer CIN
- -9 J/kg
- Mixed-layer LCL
- 948 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 132 m²/s²
- 0-3 km storm-relative helicity
- 211 m²/s²
- Significant tornado parameter
- 3.5
- Supercell composite
- 18.5
The text
As transmitted, in the capitals the NWS used until 2016.
977 ACUS11 KWNS 270215 SWOMCD SPC MCD 270213 WIZ000-ILZ000-IAZ000-MNZ000-MOZ000-NEZ000-270315- MESOSCALE DISCUSSION 2124 NWS STORM PREDICTION CENTER NORMAN OK 0913 PM CDT THU AUG 26 2004 AREAS AFFECTED...SRN WI / CNTRL AND ERN IA AND NRN MO CONCERNING...TORNADO WATCH 788... VALID 270213Z - 270315Z A NEW WW WILL BE REQUIRED WITHIN THE HOUR TO REPLACE EXPIRING TORNADO WATCH 788. STRONG TO POTENTIALLY SEVERE TSTMS HAVE EVOLVED FROM MORE DISCRETE ELEMENTS INTO CLUSTERS OVER THE PAST HOUR OR SO...LIKELY AS A RESULT OF EXPANDING/MERGING COLD POOLS. STRENGTHENING CAP ACROSS THE DOWNSTREAM WARM SECTOR IN COMBINATION WITH THE INCREASED OUTFLOW DOMINANCE OF ONGOING STORMS SUGGESTS THAT DAMAGING WINDS AND LARGE HAIL WILL BECOME THE DOMINANT SEVERE WEATHER THREATS. THOUGH AN ISOLATED TORNADO WILL REMAIN POSSIBLE GIVEN THE INCREASING LOW-LEVEL SHEAR BEING OBSERVED ON THE DVN VWP...IT APPEARS THAT THE STRENGTHENING CAP AND INCREASED COLD POOL PRODUCTION WILL TEND TO DISCOURAGE TORNADIC SUPERCELL POTENTIAL. ..MEAD.. 08/27/2004 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LOT...MKX...LSX...DVN...ARX...DMX...EAX...OAX... 40119557 43899115 43878761 40039227
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 26, 9:45 PM CDT | Severe Thunderstorm Watch | SPC | Boone, Carroll, Henderson, Henry, Jo Daviess, Mercer and 5 more | 6 hr |
| Aug 26, 11:53 PM CDT | Mesoscale Discussion | SPC | Bureau, Cook, DeKalb, DuPage, Grundy, Kane and 8 more | 97 min |
| Aug 27, 1:25 AM CDT | Severe Thunderstorm Watch | SPC | Boone, Bureau, Cook, DeKalb, DeWitt, DuPage and 25 more | 6 hr |
| Aug 27, 1:49 AM CDT | Mesoscale Discussion | SPC | Henderson, Henry, Mercer, Ogle, Rock Island, Whiteside and 1 more | 56 min |
| Aug 27, 4:36 AM CDT | Mesoscale Discussion | SPC | Cook, DeWitt, Ford, Fulton, Grundy, Hancock and 11 more | 84 min |
| Aug 27, 6:33 AM CDT | Mesoscale Discussion | SPC | Champaign, DeWitt, Ford, Iroquois, McLean, Mason and 4 more | 27 min |
| Aug 27, 9:24 AM CDT | Mesoscale Discussion | SPC | Calhoun, Greene, Jersey, Macoupin, Madison, Morgan and 2 more | 96 min |
| Aug 27, 9:40 AM CDT | Severe Thunderstorm Watch | SPC | Brown, Calhoun, Cass, Greene, Jersey, Macoupin and 7 more | 5 hr |
| Aug 27, 1:07 PM CDT | Mesoscale Discussion | SPC | Adams, Bond, Brown, Calhoun, Greene, Jersey and 6 more | 113 min |
| Aug 27, 2:45 PM CDT | Severe Thunderstorm Watch | SPC | Calhoun, Cass, Greene, Jersey, Morgan, Pike and 1 more | 6 hr |
| Aug 27, 3:49 PM CDT | Mesoscale Discussion | SPC | Calhoun, Cass, Greene, Jersey, Morgan, Pike and 1 more | 86 min |
| Aug 27, 4:10 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Bureau, Fulton, Hancock, Henderson and 14 more | 2 hr |
| Aug 26, 7:45 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Allamakee, Audubon, Benton, Black Hawk and 56 more | 90 min |
| Aug 27, 2:45 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Buchanan, Caldwell, Carroll, Chariton, Clay and 17 more | 6 hr |
Nearby
Mesoscale Discussions in Iowa, 2004Mesoscale Discussions in Wisconsin, 2004Mesoscale Discussions in Missouri, 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.