Alert archive / Illinois / Mesoscale Discussions in 2004
Mesoscale Discussion 1613
The Storm Prediction Center issued this mesoscale discussion at Jul 11, 2004, 10:14 AM CDT for 30 counties in Illinois; 14 counties in Iowa; Clark County, Lewis County, Missouri. It was in force for 91 min.
The area
The outline as issued.
The facts
- Issued
- Jul 11, 2004, 10:14 AM CDT (15:14 UTC)
- Expired
- Jul 11, 2004, 11:45 AM CDT
- In force
- 91 min
- Issued by
- the Storm Prediction Center
All 46 counties
Cedar County, IA, Clinton County, IA, Des Moines County, IA, Henry County, IA, Jackson County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Lee County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Van Buren County, IA, Washington County, IA, Bureau County, IL, Carroll County, IL, DeKalb County, IL, DuPage County, IL, Ford County, IL, Fulton County, IL, Grundy County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Kane County, IL, Kendall County, IL, Knox County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Marshall County, IL, McDonough County, IL, McLean County, IL, Mercer County, IL, Ogle County, IL, Peoria County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Tazewell County, IL, Warren County, IL, Whiteside County, IL, Will County, IL, Woodford County, IL, Clark County, MO, Lewis County, MO
The radar
The Quad Cities radar (KDVN), 83 km from the middle of the area, began a volume at 15:18 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, 3.2 hours before the alert went out and 79 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
- 339 J/kg
- Mixed-layer CIN
- -32 J/kg
- Mixed-layer LCL
- 706 m above ground
- 0-6 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- 41 m²/s²
- 0-3 km storm-relative helicity
- 35 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
946 ACUS11 KWNS 111514 SWOMCD SPC MCD 111514 ILZ000-IAZ000-MOZ000-111645- MESOSCALE DISCUSSION 1613 NWS STORM PREDICTION CENTER NORMAN OK 1014 AM CDT SUN JUL 11 2004 AREAS AFFECTED...ERN IA...NE MO THROUGH NRN AND CNTRL IL CONCERNING...OUTLOOK UPGRADE VALID 111514Z - 111645Z PORTIONS OF ERN IA...NW MO AND NRN THROUGH CNTRL IL WILL BE UPGRADED TO SLIGHT RISK ON THE 1630Z UPDATE. STORMS ARE EXPECTED TO INTENSIFY AS THEY DEVELOP ESE INTO THE AFTERNOON WITH ISOLATED DAMAGING WIND AND HAIL THE MAIN THREATS. EARLY THIS MORNING TWO AREAS OF THUNDERSTORMS WERE OBSERVED OVER THE UPPER MS VALLEY. THE MOST ORGANIZED WAS ASSOCIATED WITH AN MCV OVER WRN WI WITH A TRAILING LINE OF STORMS EXTENDING SWWD THROUGH NRN IA. ANOTHER AREA OF STORMS WAS OVER SRN IA. THE MCV WILL MOVE ESEWD INTO THE LESS UNSTABLE REGIME ACROSS WI WHICH WILL LIMIT POTENTIAL FOR STORMS ON NRN PART OF LINE TO INTENSIFY. THE STORMS ON THE SWRN PART OF THIS SYSTEM ACROSS NRN IA HAD BEEN BACKBUILDING ALONG THE LOW LEVEL JET...AND RECENT RADAR DATA SUGGEST THESE STORMS ARE NOW BEGINNING TO FORWARD PROPAGATE SEWD. HOWEVER...GIVEN THE WIDESPREAD CLOUDS AND CONVECTION S OF THIS FEATURE AND MEAN CLOUD LAYER FLOW LARGELY PARALLEL TO THE ORIENTATION OF THE STORMS...IT REMAINS UNCERTAIN WHETHER OR NOT THESE STORMS CAN MAINTAIN THEIR INTENSITY AND REMAIN ORGANIZED AS THEY DEVELOP SEWD. STORMS OVER SRN IA MAY ALSO INTENSITY INTO THE AFTERNOON. THE DES MOINES VWP SHOW 20-30 KT WLY CLOUD LAYER FLOW WHICH IS ORIENTED MORE FAVORABLY WITH RESPECT TO THE N-S LINE OF STORMS OVER SE IA TO PROMOTE EWD PROPAGATION TOWARD THE DESTABILIZING ATMOSPHERE ACROSS NRN/CNTRL IL. ..DIAL.. 07/11/2004 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LOT...ILX...LSX...DVN... 40388827 40059211 41329198 42269121 41938774
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 11, 11:40 AM CDT | Severe Thunderstorm Watch | SPC | Bureau, Carroll, Cass, Champaign, Cook, DeKalb and 40 more | 6 hr |
| Jul 11, 3:00 PM CDT | Severe Thunderstorm Watch | SPC | Calhoun, Greene, Jersey, Macoupin, Morgan, Pike and 1 more | 5 hr |
| Jul 11, 5:19 PM CDT | Mesoscale Discussion | SPC | Bond, Calhoun, Champaign, Christian, Clinton, Coles and 18 more | 116 min |
| Jul 11, 5:40 PM CDT | Severe Thunderstorm Watch | SPC | Champaign, Christian, Clark, Coles, Cumberland, DeWitt and 16 more | 5 hr |
| Jul 11, 10:33 AM CDT | Mesoscale Discussion | SPC | Adams, Audubon, Cass, Fremont, Harrison, Mills and 6 more | 117 min |
| Jul 11, 11:55 AM CDT | Severe Thunderstorm Watch | SPC | Adair, Adams, Appanoose, Cass, Clarke, Decatur and 16 more | 6 hr |
| Jul 11, 2:04 PM CDT | Mesoscale Discussion | SPC | Adams, Audubon, Cass, Fremont, Harrison, Mills and 6 more | 116 min |
Nearby
Mesoscale Discussions in Illinois, 2004Mesoscale Discussions in Iowa, 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.