Alert archive / Missouri / Mesoscale Discussions in 2003
Mesoscale Discussion 511
The Storm Prediction Center issued this mesoscale discussion at Apr 20, 2003, 1:25 AM CDT for 19 counties in Arkansas; 7 counties in Illinois; 35 counties in Missouri. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 20, 2003, 1:25 AM CDT (06:25 UTC)
- Expired
- Apr 20, 2003, 3:30 AM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 61 counties
Baxter County, AR, Boone County, AR, Clay County, AR, Cleburne County, AR, Craighead County, AR, Fulton County, AR, Greene County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Lawrence County, AR, Marion County, AR, Newton County, AR, Poinsett County, AR, Randolph County, AR, Searcy County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, Clinton County, IL, Jackson County, IL, Monroe County, IL, Perry County, IL, Randolph County, IL, Saint Clair County, IL, Washington County, IL, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, City of Saint Louis, MO, Crawford County, MO, Dent County, MO, Douglas County, MO, Dunklin County, MO, Franklin County, MO, Gasconade County, MO, Howell County, MO, Iron County, MO, Jefferson County, MO, Madison County, MO, Maries County, MO, Oregon County, MO, Osage County, MO, Ozark County, MO, Perry County, MO, Phelps County, MO, Pulaski County, MO, Reynolds County, MO, Ripley County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Shannon County, MO, Stoddard County, MO, Taney County, MO, Texas County, MO, Warren County, MO, Washington County, MO, Wayne County, MO, Wright County, MO
The radar
The Springfield radar (KSGF), 184 km from the middle of the area, began a volume at 06:28 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
Springfield, MO (KSGF), launched 00:00Z, 6.4 hours before the alert went out and 218 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
- 11 J/kg
- Mixed-layer CIN
- -140 J/kg
- Mixed-layer LCL
- 902 m above ground
- 0-6 km bulk shear
- 65 kt
- 0-1 km storm-relative helicity
- 286 m²/s²
- 0-3 km storm-relative helicity
- 217 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.2
The text
As transmitted, in the capitals the NWS used until 2016.
511 ACUS11 KWNS 200626 SWOMCD SPC MCD 200625 ILZ000-MOZ000-ARZ000-200830- MESOSCALE DISCUSSION 0511 NWS STORM PREDICTION CENTER NORMAN OK 0125 AM CDT SUN APR 20 2003 AREAS AFFECTED...NRN AR/SCNTRL AND SERN MO CONCERNING...SEVERE THUNDERSTORM WATCH 136... VALID 200625Z - 200830Z LINE OF CONVECTION ACROSS NWRN AR/SCNTRL MO WILL MAINTAIN INTENSITY AS IT TRACKS EWD OVER THE NEXT FEW HOURS. CELLS WILL HAVE A POTENTIAL FOR ISOLATED HAIL/AND OR DAMAGING WIND GUSTS. NARROW AXIS OF MID TO UPPER 60S F DEWPOINTS WAS PRESENT ACROSS CNTRL ARKANSAS RESULTING IN MLCAPE OF 500-1000 J/KG IN THIS REGION. MID-LEVEL JET OVER ERN OK/SWRN MO WAS PRODUCING STRONG DEEP LAYER SHEAR WITH 0-6 KM SHEAR AROUND 60 KT. MARGINAL INSTABILITY AND STRONG DEEP LAYER SHEAR WILL CONTINUE THE THREAT FOR SEVERE WEATHER ACROSS NCNTRL AR/SCNTRL MO THROUGH 08Z. ENVIRONMENT SHOULD BE FAVORABLE FOR A FEW MARGINALLY SEVERE STORMS WITH AN ISOLATED SUPERCELL OR BOW ECHO POSSIBLE. THE MAIN THREAT WILL BE ISOLATED HAIL AND/OR DAMAGING WINDS OVER THE NEXT FEW HOURS...THOUGH OVERALL THREAT SHOULD REMAIN ISOLATED EAST OF CURRENT WW DUE TO LIMITED INSTABILITY. ..BROYLES.. 04/20/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PAH...MEG...LSX...LZK...SGF...TSA... 36099336 36619316 38439216 38789116 38739057 38658930 37898919 37378942 36648977 35939014 35399081 35479301 35669342
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 19, 7:54 PM CDT | Mesoscale Discussion | SPC | Polk, Sebastian | 96 min |
| Apr 19, 8:55 PM CDT | Severe Thunderstorm Watch | SPC | Benton, Crawford, Sebastian, Washington | 5 hr |
| Apr 19, 9:40 PM CDT | Mesoscale Discussion | SPC | Baxter, Boone, Carroll, Franklin, Johnson, Madison and 3 more | 65 min |
| Apr 19, 10:35 PM CDT | Severe Thunderstorm Watch | SPC | Baxter, Boone, Carroll, Franklin, Johnson, Madison and 5 more | 5 hr |
| Apr 19, 10:42 PM CDT | Mesoscale Discussion | SPC | Benton, Crawford, Sebastian, Washington | 93 min |
| Apr 20, 4:00 AM CDT | Mesoscale Discussion | SPC | Clay | 2 hr |
| Apr 20, 11:52 AM CDT | Mesoscale Discussion | SPC | Arkansas, Bradley, Cleveland, Craighead, Crittenden, Cross and 8 more | 2 hr |
| Apr 20, 1:00 PM CDT | Mesoscale Discussion | SPC | Crittenden, Lee, Mississippi | 3 hr |
| Apr 20, 3:02 PM CDT | Mesoscale Discussion | SPC | Ashley, Chicot, Desha, Drew | 3 hr |
| Apr 20, 1:50 AM CDT | Severe Thunderstorm Watch | SPC | Jackson, Monroe, Perry, Randolph, Washington | 5 hr |
| Apr 20, 12:20 PM CDT | Severe Thunderstorm Watch | SPC | Clark, Crawford, Edgar, Edwards, Hamilton, Jasper and 6 more | 6 hr |
| Apr 20, 1:45 PM CDT | Severe Thunderstorm Watch | SPC | Gallatin, Hardin, Johnson, Massac, Pope, Saline | 5 hr |
| Apr 19, 8:29 PM CDT | Mesoscale Discussion | SPC | Barton, Bates, Benton, Camden, Cass, Cedar and 15 more | 2 hr |
Nearby
Mesoscale Discussions in Missouri, 2003Mesoscale Discussions in Arkansas, 2003Mesoscale Discussions in Illinois, 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.