Alert archive / Ohio / Mesoscale Discussions in 2003
Mesoscale Discussion 521
The Storm Prediction Center issued this mesoscale discussion at Apr 20, 2003, 6:31 PM EDT for Ohio County, Switzerland County, Indiana; 7 counties in Kentucky; 37 counties in Ohio. It was in force for 89 min.
The area
The outline as issued.
The facts
- Issued
- Apr 20, 2003, 6:31 PM EDT (22:31 UTC)
- Expired
- Apr 20, 2003, 8:00 PM EDT
- In force
- 89 min
- Issued by
- the Storm Prediction Center
All 46 counties
Ohio County, IN, Switzerland County, IN, Boone County, KY, Bracken County, KY, Campbell County, KY, Gallatin County, KY, Greenup County, KY, Kenton County, KY, Pendleton County, KY, Adams County, OH, Ashland County, OH, Brown County, OH, Butler County, OH, Champaign County, OH, Clark County, OH, Clermont County, OH, Clinton County, OH, Coshocton County, OH, Crawford County, OH, Delaware County, OH, Fairfield County, OH, Fayette County, OH, Franklin County, OH, Greene County, OH, Hamilton County, OH, Highland County, OH, Hocking County, OH, Holmes County, OH, Huron County, OH, Knox County, OH, Licking County, OH, Madison County, OH, Marion County, OH, Medina County, OH, Montgomery County, OH, Morrow County, OH, Perry County, OH, Pickaway County, OH, Pike County, OH, Richland County, OH, Ross County, OH, Scioto County, OH, Union County, OH, Vinton County, OH, Warren County, OH, Wayne County, OH
The radar
The Cincinnati radar (KILN), 72 km from the middle of the area, began a volume at 22:32 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
Cncnati-Daytn, OH (KILN), launched 12:00Z, 10.5 hours before the alert went out and 70 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
- 54 J/kg
- Mixed-layer CIN
- -227 J/kg
- Mixed-layer LCL
- 1119 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- -56 m²/s²
- 0-3 km storm-relative helicity
- -84 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
686 ACUS11 KWNS 202231 SWOMCD SPC MCD 202231 OHZ000-KYZ000-INZ000-210000- MESOSCALE DISCUSSION 0521 NWS STORM PREDICTION CENTER NORMAN OK 0531 PM CDT SUN APR 20 2003 AREAS AFFECTED...OH CONCERNING...SEVERE THUNDERSTORM WATCH 141... VALID 202231Z - 210000Z TWO CLUSTERS OF STRONG TO SEVERE TSTMS CONTINUE MOVING THROUGH WW 141 ATTM. THE LEADING STORMS ACROSS N-CNTRL OH HAVE BEGUN TO INTERACT WITH LAKE ERIE BAROCLINIC ZONE WHERE ENHANCED LOW LEVEL SHEAR APPEARS TO BE FAVORING TORNADIC POTENTIAL WITH A RECENT REPORT IN SENECA COUNTY. THESE STORMS WERE MOVING TO THE NORTHEAST AT NEAR 50KT SHOULD CONTINUE TO POSE A DAMAGING WIND THREAT ALONG THE SOUTH SHORE OF THE LAKE FOR THE NEXT 1-2 HOURS. A SECOND CLUSTER OF STRONG TO SEVERE STORMS WAS MOVING INTO MONTGOMERY...BUTLER...AND HAMILTON COUNTIES OF SOUTHWEST OH. THIS ACTIVITY WILL SPREAD EWD ACROSS S-CNTRL OH THROUGH 0100. LATEST RUC FCST SOUNDINGS INDICATE MLCAPE TO 800 J/KG WITH VERY FAVORABLE DEEP LAYER SHEAR FOR SUPERCELLS. IN ADDITION...BACKED LOW LEVEL FLOW AND HIGHER SRH SUGGEST SOME TORNADO POTENTIAL INVOF OUTFLOW BOUNDARY FROM NRN CONVECTION.... ACROSS CLARK AND MONTGOMERY COUNTIES. STRONGER STORM SCALE CONVERGENCE ALONG THIS BOUNDARY MAY ADDITIONALLY ENHANCE STORM UPDRAFTS DESPITE RELATIVELY LOW INSTABILITY. ..CARBIN.. 04/20/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PBZ...RLX...CLE...ILN...LMK... 38788533 40128392 41298241 41588141 40798164 38868270 38508265
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 20, 12:52 PM EDT | Mesoscale Discussion | SPC | Benton, Boone, Brown, Carroll, Cass, Clay and 60 more | 2 hr |
| Apr 20, 1:20 PM EDT | Severe Thunderstorm Watch | SPC | Adams, Allen, Bartholomew, Benton, Blackford, Boone and 75 more | 6 hr |
| Apr 20, 4:15 PM EDT | Severe Thunderstorm Watch | SPC | Dearborn, Franklin, Jefferson, Ohio, Ripley, Switzerland and 2 more | 6 hr |
| Apr 20, 5:35 PM EDT | Tornado Watch | SPC | Clark, Crawford, Floyd, Harrison, Perry | 5 hr |
| Apr 20, 7:04 PM EDT | Mesoscale Discussion | SPC | Clark, Crawford, Floyd, Harrison | 116 min |
| Apr 20, 2:00 PM EDT | Mesoscale Discussion | SPC | Ballard, Breckinridge, Butler, Caldwell, Calloway, Carlisle and 24 more | 3 hr |
| Apr 20, 2:45 PM EDT | Severe Thunderstorm Watch | SPC | Ballard, Breckinridge, Butler, Caldwell, Calloway, Carlisle and 22 more | 5 hr |
| Apr 20, 4:29 PM EDT | Mesoscale Discussion | SPC | Adair, Allen, Anderson, Barren, Bath, Bourbon and 43 more | 2 hr |
| Apr 20, 7:25 PM EDT | Severe Thunderstorm Watch | SPC | Allen, Barren, Calloway, Christian, Graves, Logan and 5 more | 6 hr |
| Apr 20, 7:53 PM EDT | Mesoscale Discussion | SPC | Ashland, Coshocton, Delaware, Holmes, Knox, Licking and 4 more | 67 min |
Nearby
Mesoscale Discussions in Ohio, 2003Mesoscale Discussions in Kentucky, 2003Mesoscale Discussions in Indiana, 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.