Alert archive / Iowa / Mesoscale Discussions in 2011
Mesoscale Discussion 1313
The Storm Prediction Center issued this mesoscale discussion at Jun 20, 2011, 7:29 AM CDT for 12 counties in Iowa. It was in force for 61 min.
The area
The outline as issued.
The facts
- Issued
- Jun 20, 2011, 7:29 AM CDT (12:29 UTC)
- Expired
- Jun 20, 2011, 8:30 AM CDT
- In force
- 61 min
- Issued by
- the Storm Prediction Center
Counties Black Hawk County, IA, Grundy County, IA, Hamilton County, IA, Hardin County, IA, Jasper County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Polk County, IA, Poweshiek County, IA, Story County, IA, Tama County, IA
The radar
The Des Moines radar (KDMX), 54 km from the middle of the area, began a volume at 12:33 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
Davenport, (KDVN), launched 12:00Z, 0.5 hours before the alert went out and 214 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
- 739 J/kg
- Mixed-layer CIN
- -240 J/kg
- Mixed-layer LCL
- 1198 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- -14 m²/s²
- 0-3 km storm-relative helicity
- 43 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
062 ACUS11 KWNS 201230 SWOMCD SPC MCD 201229 IAZ000-201330- MESOSCALE DISCUSSION 1313 NWS STORM PREDICTION CENTER NORMAN OK 0729 AM CDT MON JUN 20 2011 AREAS AFFECTED...CENTRAL IA CONCERNING...SEVERE THUNDERSTORM WATCH 521... VALID 201229Z - 201330Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 521 CONTINUES. OBJECTIVE ANALYSES INDICATED RESIDUAL MODERATE INSTABILITY EXTENDING INTO SRN IA/NRN MO AND EFFECTIVE BULK SHEAR OF 40-60 KT REMAIN SUPPORTIVE OF ORGANIZED STORMS. ADDITIONAL TSTMS ARE POSSIBLE THIS MORNING WITHIN A WAA REGIME IN THE NOSE OF 45-65 KT SWLY LLJ EXTENDING INTO THE SWRN PERIPHERY OF A TSTM COMPLEX CURRENTLY LOCATED ACROSS CENTRAL/ERN IA AND NERN MO. HOWEVER...WARMING CLOUD TOP TEMPERATURES AND WEAKENING STORM INTENSITIES ACROSS THE REMAINDER OF WW 521 SUGGEST THE OVERALL SEVERE WEATHER THREAT SHOULD CONTINUE TO WANE ACROSS CENTRAL IA. ..PETERS.. 06/20/2011 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...DVN...DMX... LAT...LON 41149341 42569418 42629194 41169243 41149341
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 19, 9:16 PM CDT | Mesoscale Discussion | SPC | Adair, Adams, Appanoose, Audubon, Boone, Carroll and 31 more | 59 min |
| Jun 19, 9:49 PM CDT | Tornado Watch | SPC | Fremont, Harrison, Mills, Monona, Montgomery, Page and 2 more | 6 hr |
| Jun 19, 11:42 PM CDT | Severe Thunderstorm Watch | SPC | Benton, Cedar, Clinton, Des Moines, Henry, Iowa and 10 more | 6 hr |
| Jun 20, 1:40 AM CDT | Mesoscale Discussion | SPC | Adair, Adams, Appanoose, Audubon, Boone, Carroll and 24 more | 35 min |
| Jun 20, 3:27 AM CDT | Mesoscale Discussion | SPC | Adair, Adams, Appanoose, Audubon, Boone, Carroll and 28 more | 33 min |
| Jun 20, 3:46 AM CDT | Severe Thunderstorm Watch | SPC | Adair, Audubon, Black Hawk, Boone, Calhoun, Carroll and 26 more | 5 hr |
| Jun 20, 4:08 AM CDT | Mesoscale Discussion | SPC | Benton, Cedar, Clinton, Davis, Des Moines, Henry and 12 more | 67 min |
| Jun 20, 3:08 PM CDT | Tornado Watch | SPC | Audubon, Carroll, Cass, Crawford, Fremont, Harrison and 6 more | 7 hr |
| Jun 20, 5:55 PM CDT | Mesoscale Discussion | SPC | Adair, Audubon, Boone, Calhoun, Carroll, Dallas and 15 more | 65 min |
| Jun 20, 6:17 PM CDT | Mesoscale Discussion | SPC | Fremont, Harrison, Mills, Monona, Plymouth, Woodbury | 58 min |
| Jun 20, 6:53 PM CDT | Tornado Watch | SPC | Adair, Adams, Audubon, Boone, Buena Vista, Calhoun and 41 more | 6 hr |
Nearby
Mesoscale Discussions in Iowa, 2011Every mesoscale discussion in 2011
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.