Alert archive / Indiana / Mesoscale Discussions in 2003
Mesoscale Discussion 1920
The Storm Prediction Center issued this mesoscale discussion at Jul 20, 2003, 6:23 PM CDT for 4 states. It was in force for 97 min.
The area
The outline as issued.
The facts
- Issued
- Jul 20, 2003, 6:23 PM CDT (23:23 UTC)
- Expired
- Jul 20, 2003, 8:00 PM CDT
- In force
- 97 min
- Issued by
- the Storm Prediction Center
All 38 counties
Boone County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Grundy County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Lake County, IL, LaSalle County, IL, Livingston County, IL, McHenry County, IL, Will County, IL, Winnebago County, IL, Elkhart County, IN, Fulton County, IN, Jasper County, IN, Kosciusko County, IN, LaGrange County, IN, Lake County, IN, LaPorte County, IN, Marshall County, IN, Newton County, IN, Noble County, IN, Porter County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Steuben County, IN, Whitley County, IN, Berrien County, MI, Cass County, MI, Saint Joseph County, MI, Van Buren County, MI, Kenosha County, WI, Racine County, WI, Rock County, WI, Walworth County, WI
The radar
The Chicago radar (KLOT), 31 km from the middle of the area, began a volume at 23:23 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, 11.4 hours before the alert went out and 183 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
- 649 J/kg
- Mixed-layer CIN
- -220 J/kg
- Mixed-layer LCL
- 888 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 74 m²/s²
- 0-3 km storm-relative helicity
- 115 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
958 ACUS11 KWNS 202324 SWOMCD SPC MCD 202323 OHZ000-INZ000-MIZ000-ILZ000-WIZ000-210100- MESOSCALE DISCUSSION 1920 NWS STORM PREDICTION CENTER NORMAN OK 0623 PM CDT SUN JUL 20 2003 AREAS AFFECTED...SERN WI...NERN IL AND NRN IND...SWRN LOWER MI CONCERNING...SEVERE THUNDERSTORM WATCH 774... VALID 202323Z - 210100Z STRONGEST STORMS ARE EXPECTED TO PERSIST IN SRN PORTION OF WW 774 MAINLY ACROSS NRN IL AND EVENTUALLY EWD INTO NRN IND. A WW MAY BE NEEDED FOR PORTIONS OF NRN IND AND SWRN LOWER MI WITHIN THE NEXT HOUR. STORMS CONTINUE DEVELOPING ALONG INSTABILITY GRADIENT ON AN E-W BOUNDARY ACROSS NRN IL. THIS ACTIVITY IS EXPECTED TO CONTINUE DEVELOPING EWD INTO NRN IND AND SRN LOWER MI WHERE THE ATMOSPHERE REMAINS MODERATELY UNSTABLE. UNIDIRECTIONAL WIND PROFILES WITH DEEP SHEAR FROM 35 TO 40 KT WILL CONTINUE TO SUPPORT UPDRAFT ROTATION. THROUGH LOW LEVEL CONVERGENCE IS NOT PARTICULARLY STRONG...CAP IS WEAK AND WARM ADVECTION IS EXPECTED TO INCREASE IN THIS REGION AS SWLY LOW LEVEL JET DEVELOPS THIS EVENING. ..DIAL.. 07/20/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...IWX...GRR...LOT...MKX... 40798876 41868924 42778909 42878758 41588469 40898588
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 20, 4:25 PM CDT | Severe Thunderstorm Watch | SPC | Boone, Cook, DeKalb, DuPage, Grundy, Kane and 8 more | 5 hr |
| Jul 20, 12:41 PM CDT | Mesoscale Discussion | SPC | Steuben | 64 min |
| Jul 20, 1:20 PM CDT | Severe Thunderstorm Watch | SPC | DeKalb, Steuben | 6 hr |
| Jul 20, 3:37 PM CDT | Mesoscale Discussion | SPC | Steuben | 113 min |
| Jul 20, 6:45 PM CDT | Severe Thunderstorm Watch | SPC | DeKalb, Elkhart, Kosciusko, LaGrange, LaPorte, Marshall and 5 more | 5 hr |
| Jul 20, 1:16 PM CDT | Mesoscale Discussion | SPC | Alger, Baraga, Dickinson, Gogebic, Houghton, Iron and 3 more | 119 min |
| Jul 20, 1:55 PM CDT | Severe Thunderstorm Watch | SPC | Alger, Baraga, Delta, Dickinson, Gogebic, Houghton and 4 more | 7 hr |
| Jul 20, 3:27 PM CDT | Mesoscale Discussion | SPC | Alger, Baraga, Delta, Dickinson, Gogebic, Houghton and 4 more | 63 min |
| Jul 20, 6:47 PM CDT | Mesoscale Discussion | SPC | Baraga, Delta, Dickinson, Gogebic, Houghton, Iron and 3 more | 88 min |
| Jul 20, 4:14 AM CDT | Mesoscale Discussion | SPC | Pierce | 3 hr |
Nearby
Mesoscale Discussions in Indiana, 2003Mesoscale Discussions in Illinois, 2003Mesoscale Discussions in Michigan, 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.