Alert archive / Illinois / Mesoscale Discussions in 2004
Mesoscale Discussion 511
The Storm Prediction Center issued this mesoscale discussion at Apr 30, 2004, 10:59 AM CDT for 5 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 30, 2004, 10:59 AM CDT (15:59 UTC)
- Expired
- Apr 30, 2004, 1:00 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 122 counties
Clay County, AR, Cleburne County, AR, Craighead County, AR, Greene County, AR, Independence County, AR, Jackson County, AR, Lawrence County, AR, Mississippi County, AR, Poinsett County, AR, Randolph County, AR, Sharp County, AR, White County, AR, Adams County, IL, Alexander County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Fulton County, IL, Gallatin County, IL, Greene County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Jersey County, IL, Johnson County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Mason County, IL, Massac County, IL, McLean County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Perry County, IL, Piatt County, IL, Pike County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Saline County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Tazewell County, IL, Union County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Ballard County, KY, Calloway County, KY, Carlisle County, KY, Crittenden County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, City of Saint Louis, MO, Crawford County, MO, Dunklin County, MO, Franklin County, MO, Iron County, MO, Jefferson County, MO, Lincoln County, MO, Madison County, MO, Mississippi County, MO, Montgomery County, MO, New Madrid County, MO, Oregon County, MO, Pemiscot County, MO, Perry County, MO, Pike County, MO, Ralls County, MO, Reynolds County, MO, Ripley County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Scott County, MO, Shannon County, MO, Stoddard County, MO, Warren County, MO, Washington County, MO, Wayne County, MO, Dyer County, TN, Gibson County, TN, Lake County, TN, Lauderdale County, TN, Obion County, TN, Tipton County, TN, Weakley County, TN
The radar
The St Louis radar (KLSX), 100 km from the middle of the area, began a volume at 16:00 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 nearest sounding before it
Lincoln, IL (KILX), launched 12:00Z, 4.0 hours before the alert went out and 288 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
- 720 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 72 m²/s²
- 0-3 km storm-relative helicity
- 79 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
095 ACUS11 KWNS 301600 SWOMCD SPC MCD 301559 INZ000-ILZ000-KYZ000-TNZ000-MOZ000-ARZ000-301800- MESOSCALE DISCUSSION 0511 NWS STORM PREDICTION CENTER NORMAN OK 1059 AM CDT FRI APR 30 2004 AREAS AFFECTED...NE AR/ERN MO INTO IL/WRN KY CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 301559Z - 301800Z AREA IS BEING MONITORED. WW IS NOT CURRENTLY ANTICIPATED...BUT COULD BECOME NECESSARY. FORCING ASSOCIATED WITH WEAK SOUTHWESTERLY MID-LEVEL JET STREAK ...LIFTING ACROSS THE OZARKS INTO THE MID MISSISSIPPI VALLEY... APPEARS TO BE PROVIDING SUPPORT FOR ONGOING CONVECTIVE DEVELOPMENT FROM CENTRAL MISSOURI INTO NORTHWEST ARKANSAS. ACTIVITY IS INTENSIFYING...AND A GRADUAL CONSOLIDATION OF SEPARATE CLUSTERS INTO ONE LARGE MESOSCALE CONVECTIVE SYSTEM IS EXPECTED INTO EARLY AFTERNOON. WHILE UPDRAFTS STILL APPEAR BASED ABOVE NEAR SURFACE INVERSION LAYER...AS SURFACE TEMPERATURES ALONG/ AHEAD OF CONVECTION WARM INTO THE MID 70S...CONVECTION LIKELY WILL BECOME SURFACE BASED AS IT APPROACHES THE MISSISSIPPI RIVER. AS THIS OCCURS...POTENTIAL FOR SPORADIC DAMAGING WIND GUSTS IN 25 TO 35 KT MEAN FLOW ENVIRONMENT WILL INCREASE...WHILE STRONGEST CELLS CONTINUE TO PRODUCE HAIL. ..KERR.. 04/30/2004 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PAH...LOT...ILX...MEG...LSX...DVN...LZK...SGF... 39499181 40169104 40758964 40458815 39628803 38008794 36908802 36118872 35488976 35209122 35299225 35999196 36969143 38309135
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 30, 4:10 PM CDT | Mesoscale Discussion | SPC | Crawford, Franklin, Logan, Scott, Sebastian | 2 hr |
| Apr 30, 4:40 PM CDT | Severe Thunderstorm Watch | SPC | Benton, Carroll, Crawford, Franklin, Johnson, Logan and 4 more | 5 hr |
| Apr 30, 1:52 PM CDT | Mesoscale Discussion | SPC | Alexander, Clinton, Franklin, Gallatin, Hamilton, Hardin and 15 more | 113 min |
| Apr 30, 5:50 PM CDT | Severe Thunderstorm Watch | SPC | Crawford, Lawrence | 3 hr |
Nearby
Mesoscale Discussions in Illinois, 2004Mesoscale Discussions in Missouri, 2004Mesoscale Discussions in Arkansas, 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.