Alert archive / Indiana / Mesoscale Discussions in 2003
Mesoscale Discussion 643
The Storm Prediction Center issued this mesoscale discussion at Apr 30, 2003, 3:24 PM CDT for 4 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 30, 2003, 3:24 PM CDT (20:24 UTC)
- Expired
- Apr 30, 2003, 5:30 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 84 counties
Des Moines County, IA, Louisa County, IA, Muscatine County, IA, Adams County, IL, Brown County, IL, Bureau County, IL, Cass County, IL, Champaign County, IL, DeWitt County, IL, Ford County, IL, Fulton County, IL, Grundy County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Iroquois County, IL, Kankakee County, IL, Kendall County, IL, Knox County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, McLean County, IL, Menard County, IL, Mercer County, IL, Peoria County, IL, Piatt County, IL, Putnam County, IL, Rock Island County, IL, Schuyler County, IL, Stark County, IL, Tazewell County, IL, Vermilion County, IL, Warren County, IL, Will County, IL, Woodford County, IL, Adams County, IN, Allen County, IN, Benton County, IN, Blackford County, IN, Boone County, IN, Carroll County, IN, Cass County, IN, Clinton County, IN, DeKalb County, IN, Delaware County, IN, Elkhart County, IN, Fountain County, IN, Fulton County, IN, Grant County, IN, Hamilton County, IN, Howard County, IN, Huntington County, IN, Jasper County, IN, Jay County, IN, Kosciusko County, IN, LaGrange County, IN, Lake County, IN, LaPorte County, IN, Madison County, IN, Marshall County, IN, Miami County, IN, Montgomery County, IN, Newton County, IN, Noble County, IN, Porter County, IN, Pulaski County, IN, Randolph County, IN, Saint Joseph County, IN, Starke County, IN, Steuben County, IN, Tippecanoe County, IN, Tipton County, IN, Wabash County, IN, Warren County, IN, Wells County, IN, White County, IN, Whitley County, IN, Berrien County, MI
The radar
The Chicago radar (KLOT), 100 km from the middle of the area, began a volume at 20:28 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, 8.4 hours before the alert went out and 72 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 925 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- -31 m²/s²
- 0-3 km storm-relative helicity
- 31 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
625 ACUS11 KWNS 302025 SWOMCD SPC MCD 302024 OHZ000-INZ000-MIZ000-ILZ000-IAZ000-302230- MESOSCALE DISCUSSION 0643 NWS STORM PREDICTION CENTER NORMAN OK 0324 PM CDT WED APR 30 2003 AREAS AFFECTED...NRN IL/NRN IN CONCERNING...SEVERE THUNDERSTORM WATCH 187... VALID 302024Z - 302230Z CONVECTION DEVELOPING ALONG THE WARM FRONT SHOULD STRENGTHEN OVER THE NEXT FEW HOURS. ISOLATED LARGE HAIL AND/OR DAMAGING WINDS IS LIKELY WITH THE STRONGER CELLS. WARM FRONT EXTENDED E-W ACROSS NRN IL/NRN IN WITH MODERATE INSTABILITY EXISTING ACROSS THIS AREA WITH MLCAPE FROM 1000 TO 2000 J/KG. INCREASING LOW-LEVEL CONVERGENCE AND LARGE-SCALE FORCING FROM A VORTICITY MAX ACROSS ERN IA EVIDENT ON WV IMAGERY WILL BE SUFFICIENT FOR THE DEVELOPMENT OF NEW CELLS ALONG THE FRONT. DEEP LAYER SHEAR WAS ALSO INCREASING WITH 0-6 KM SHEAR VALUES AROUND 40 KTS SUGGESTING A SUPERCELL WILL BE POSSIBLE. COLD AIR ALOFT WITH 500 MB TEMPS NEAR 15 C SHOULD PROMOTE A POTENTIAL FOR LARGE HAIL. ALSO...CELLS THAT CAN ORGANIZE COLD POOLS WILL HAVE A POTENTIAL FOR WIND DAMAGE. ..BROYLES.. 04/30/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ILN...IWX...IND...LOT...ILX...LSX...DVN... 40029129 40909135 41539125 41748954 41818761 41898615 41818492 41338474 40788475 40188481 40048577 39978740 39848884 39789022 39759105
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 30, 11:04 AM CDT | Mesoscale Discussion | SPC | Boone, Carroll, Cook, DeKalb, DuPage, Jo Daviess and 10 more | 116 min |
| Apr 30, 12:22 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Cass, Champaign, Christian, Coles and 37 more | 113 min |
| Apr 30, 1:00 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Brown, Bureau, Cass, Champaign, DeWitt and 30 more | 5 hr |
| Apr 30, 5:15 PM CDT | Tornado Watch | SPC | Adams, Hancock, Henderson, McDonough, Mercer, Rock Island and 2 more | 6 hr |
| Apr 30, 5:50 PM CDT | Severe Thunderstorm Watch | SPC | Bureau, Cook, DeKalb, DuPage, Grundy, Henry and 15 more | 5 hr |
| Apr 29, 7:00 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Audubon, Boone, Carroll, Cass and 13 more | 3 hr |
| Apr 29, 7:30 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Adams, Audubon, Boone, Carroll, Cass and 17 more | 7 hr |
| Apr 29, 10:40 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Audubon, Boone, Carroll, Cass and 17 more | 2 hr |
| Apr 30, 2:49 PM CDT | Mesoscale Discussion | SPC | Appanoose, Clarke, Decatur, Lucas, Monroe, Page and 3 more | 116 min |
Nearby
Mesoscale Discussions in Indiana, 2003Mesoscale Discussions in Illinois, 2003Mesoscale Discussions in Iowa, 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; radar from the NEXRAD Level II archive.