Alert archive / Iowa / Mesoscale Discussions in 2012
Mesoscale Discussion 698
The Storm Prediction Center issued this mesoscale discussion at May 4, 2012, 3:52 PM CDT for 4 states. It was in force for 53 min.
The area
The outline as issued.
The facts
- Issued
- May 4, 2012, 3:52 PM CDT (20:52 UTC)
- Expired
- May 4, 2012, 4:45 PM CDT
- In force
- 53 min
- Issued by
- the Storm Prediction Center
All 66 counties
Buena Vista County, IA, Cerro Gordo County, IA, Cherokee County, IA, Clay County, IA, Dickinson County, IA, Emmet County, IA, Franklin County, IA, Hancock County, IA, Humboldt County, IA, Ida County, IA, Kossuth County, IA, Lyon County, IA, O'Brien County, IA, Osceola County, IA, Palo Alto County, IA, Plymouth County, IA, Pocahontas County, IA, Sac County, IA, Sioux County, IA, Winnebago County, IA, Woodbury County, IA, Worth County, IA, Wright County, IA, Blue Earth County, MN, Brown County, MN, Cottonwood County, MN, Faribault County, MN, Freeborn County, MN, Jackson County, MN, Le Sueur County, MN, Martin County, MN, Murray County, MN, Nobles County, MN, Rice County, MN, Rock County, MN, Steele County, MN, Waseca County, MN, Watonwan County, MN, Antelope County, NE, Boyd County, NE, Cedar County, NE, Dakota County, NE, Dixon County, NE, Garfield County, NE, Holt County, NE, Knox County, NE, Loup County, NE, Madison County, NE, Pierce County, NE, Rock County, NE, Thurston County, NE, Wayne County, NE, Wheeler County, NE, Bon Homme County, SD, Charles Mix County, SD, Clay County, SD, Douglas County, SD, Gregory County, SD, Hanson County, SD, Hutchinson County, SD, Lincoln County, SD, McCook County, SD, Minnehaha County, SD, Turner County, SD, Union County, SD, Yankton County, SD
The radar
The Sioux Falls radar (KFSD), 56 km from the middle of the area, began a volume at 20:53 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
Omaha, NE (KOAX), launched 12:00Z, 8.9 hours before the alert went out and 205 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
- 2705 J/kg
- Mixed-layer CIN
- -17 J/kg
- Mixed-layer LCL
- 584 m above ground
- 0-6 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- 10 m²/s²
- 0-3 km storm-relative helicity
- 98 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
752 ACUS11 KWNS 042052 SWOMCD SPC MCD 042052 MNZ000-IAZ000-NEZ000-SDZ000-042145- MESOSCALE DISCUSSION 0698 NWS STORM PREDICTION CENTER NORMAN OK 0352 PM CDT FRI MAY 04 2012 AREAS AFFECTED...SERN SD...NERN NEB...SRN MN...NRN IA CONCERNING...SEVERE THUNDERSTORM WATCH 239... VALID 042052Z - 042145Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 239 CONTINUES. SUMMARY...SEVERE THUNDERSTORMS WILL CONTINUE ALONG A CORRIDOR FROM SCNTRL MN...SWWD INTO NERN NEB INTO THE EARLY EVENING HOURS. DISCUSSION...CONVECTION HAS REJUVENATED ALONG SRN FLANK OF LONGER-LIVED MCS AS IT TRACKS ACROSS THE UPPER MS VALLEY REGION. ALTHOUGH SOMEWHAT COMPLEX...A FEW SUPERCELLS HAVE EVOLVED ALONG A WEAK BOUNDARY THAT STRETCHES FROM THE MN/IA BORDER...SWWD INTO EXTREME NERN NEB. GIVEN THE AXIS OF INSTABILITY THAT EXISTS ALONG THIS CORRIDOR IT APPEARS THE ONGOING CONVECTION WILL MAINTAIN ITS INTENSITY AS IT MOVES ACROSS CNTRL PORTIONS OF WW239. WHILE A FEW OF THE SUPERCELLS ALONG THE MN/IA BORDER HAVE PRODUCED ISOLATED TORNADOES...LATEST THINKING IS THE COMPLEX STORM INTERACTIONS AND THE PROPENSITY FOR UPWARD LINEAR EVOLUTION WILL LIMIT FUTURE TORNADIC POTENTIAL. ..DARROW.. 05/04/2012 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MPX...DMX...FSD...OAX...GID...LBF...UNR... LAT...LON 43409955 44569305 42689306 41539955 43409955
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 3, 7:09 PM CDT | Tornado Watch | SPC | Adair, Adams, Appanoose, Cass, Cedar, Clarke and 23 more | 6 hr |
| May 3, 11:18 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Appanoose, Cass, Cedar, Clarke and 23 more | 27 min |
| May 4, 12:53 AM CDT | Severe Thunderstorm Watch | SPC | Des Moines, Henry, Jefferson, Lee, Van Buren | 4 hr |
| May 4, 2:16 AM CDT | Mesoscale Discussion | SPC | Appanoose, Davis, Decatur, Des Moines, Henry, Jefferson and 9 more | 119 min |
| May 4, 1:50 PM CDT | Mesoscale Discussion | SPC | Buena Vista, Cherokee, Clay, Dickinson, Emmet, Ida and 7 more | 25 min |
| May 4, 2:00 PM CDT | Severe Thunderstorm Watch | SPC | Buena Vista, Calhoun, Carroll, Cerro Gordo, Cherokee, Clay and 23 more | 9 hr |
| May 4, 5:31 PM CDT | Mesoscale Discussion | SPC | Audubon, Benton, Black Hawk, Boone, Bremer, Buchanan and 66 more | 29 min |
| May 4, 5:52 PM CDT | Severe Thunderstorm Watch | SPC | Fremont, Harrison, Mills, Monona, Montgomery, Page and 2 more | 5 hr |
| May 4, 6:01 PM CDT | Severe Thunderstorm Watch | SPC | Benton, Black Hawk, Boone, Bremer, Buchanan, Butler and 22 more | 3 hr |
| May 4, 6:49 AM CDT | Mesoscale Discussion | SPC | Antelope, Boyd, Cedar, Dixon, Holt, Keya Paha and 5 more | 116 min |
Nearby
Mesoscale Discussions in Iowa, 2012Mesoscale Discussions in Minnesota, 2012Mesoscale Discussions in Nebraska, 2012Every mesoscale discussion in 2012
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.