Alert archive / Iowa / Mesoscale Discussions in 2003
Mesoscale Discussion 2256
The Storm Prediction Center issued this mesoscale discussion at Aug 25, 2003, 7:38 PM CDT for 34 counties in Iowa; Fillmore County, Houston County, Mower County, Minnesota; Crawford County, Grant County, Vernon County, Wisconsin. It was in force for 67 min.
The area
The outline as issued.
The facts
- Issued
- Aug 25, 2003, 7:38 PM CDT (00:38 UTC)
- Expired
- Aug 25, 2003, 8:45 PM CDT
- In force
- 67 min
- Issued by
- the Storm Prediction Center
All 40 counties
Allamakee County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Calhoun County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Clayton County, IA, Delaware County, IA, Emmet County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Howard County, IA, Humboldt County, IA, Kossuth County, IA, Marshall County, IA, Mitchell County, IA, Palo Alto County, IA, Pocahontas County, IA, Story County, IA, Tama County, IA, Webster County, IA, Winnebago County, IA, Winneshiek County, IA, Worth County, IA, Wright County, IA, Fillmore County, MN, Houston County, MN, Mower County, MN, Crawford County, WI, Grant County, WI, Vernon County, WI
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, 0.6 hours before the alert went out and 222 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
- 2110 J/kg
- Mixed-layer CIN
- -142 J/kg
- Mixed-layer LCL
- 1896 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 100 m²/s²
- 0-3 km storm-relative helicity
- 93 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.6
The text
As transmitted, in the capitals the NWS used until 2016.
265 ACUS11 KWNS 260039 SWOMCD SPC MCD 260038 WIZ000-IAZ000-MNZ000-260145- MESOSCALE DISCUSSION 2256 NWS STORM PREDICTION CENTER NORMAN OK 0738 PM CDT MON AUG 25 2003 AREAS AFFECTED...NRN IA...FAR SRN MN...AND FAR SWRN WI CONCERNING...SEVERE THUNDERSTORM WATCH 886... VALID 260038Z - 260145Z SEVERE THUNDERSTORM WATCH 886 CONTINUES ACROSS NRN IA...FAR SRN MN...AND FAR SWRN WI. AT 0020Z...STRONGEST CONVECTION WAS LOCATED OVER CALHOUN AND POCAHONTAS COUNTIES IN N-CENTRAL IA...MOVING 250/35-40KT. ADDITIONAL ACTIVITY WAS LOCATED JUST SOUTH OF THE WW 886 AREA FROM 30 NW - 50 NE OF DSM. WITH CONVECTION HEADED TOWARD INSTABILITY MAX WITH 100MB MLCAPE OF 3000-3500 J/KG ACROSS THE ERN/NRN HALF OF IA...SEVERE THUNDERSTORM THREAT WILL LIKELY CONTINUE DURING THE NEXT FEW HOURS. MULTICELLULAR CLUSTERS WITH NUMEROUS OUTFLOW BOUNDARIES WILL LIKELY GENERATE ADDITIONAL CELLS ACROSS N-CENTRAL IA DURING THE NEXT 1-2 HOURS. PLUME OF STEEP LAPSE RATES...EVIDENCED BY 700-500MB LAPSE RATE OF 7.5 C/KM AT DVN AT 00Z...WILL SUPPORT STRONG CONVECTIVE UPDRAFTS SUPPORTING LARGE HAIL WITH STRONGER CORES. DCAPE AROUND 1500 J/KG AND OUTFLOW DOMINANT NATURE OF ONGOING ACTIVITY SUGGEST DAMAGING WINDS WILL ALSO BE LIKELY. ..BANACOS.. 08/26/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...DVN...ARX...MPX...DMX...FSD... 42219138 41979287 42019451 42799501 43419485 43639316 43899069 42649062
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 25, 7:03 PM CDT | Mesoscale Discussion | SPC | Benton, Cedar, Davis, Des Moines, Henry, Iowa and 13 more | 87 min |
| Aug 25, 8:45 PM CDT | Severe Thunderstorm Watch | SPC | Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 13 more | 5 hr |
| Aug 26, 2:19 PM CDT | Mesoscale Discussion | SPC | Appanoose, Clarke, Davis, Decatur, Des Moines, Henry and 11 more | 116 min |
| Aug 26, 4:45 PM CDT | Mesoscale Discussion | SPC | Des Moines, Henry, Jefferson, Lee, Van Buren | 90 min |
| Aug 25, 7:04 PM CDT | Mesoscale Discussion | SPC | Beltrami, Clearwater, Itasca, Kittson, Koochiching, Marshall and 4 more | 56 min |
| Aug 25, 8:05 PM CDT | Tornado Watch | SPC | Itasca, Koochiching, Saint Louis | 6 hr |
| Aug 25, 10:02 PM CDT | Mesoscale Discussion | SPC | Itasca, Lake, Saint Louis | 58 min |
| Aug 25, 11:10 PM CDT | Tornado Watch | SPC | Aitkin, Carlton, Kanabec, Mille Lacs, Pine | 6 hr |
| Aug 26, 12:21 AM CDT | Mesoscale Discussion | SPC | Dane, Green, Iowa, Jefferson, Lafayette, Rock and 2 more | 84 min |
Nearby
Mesoscale Discussions in Iowa, 2003Mesoscale Discussions in Minnesota, 2003Mesoscale Discussions in Wisconsin, 2003Every mesoscale discussion in 2003
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.