Alert archive / Iowa / Mesoscale Discussions in 2008
Mesoscale Discussion 721
The Storm Prediction Center issued this mesoscale discussion at Apr 25, 2008, 2:24 AM CDT for 20 counties in Iowa; 9 counties in Missouri. It was in force for 66 min.
The area
The outline as issued.
The facts
- Issued
- Apr 25, 2008, 2:24 AM CDT (07:24 UTC)
- Expired
- Apr 25, 2008, 3:30 AM CDT
- In force
- 66 min
- Issued by
- the Storm Prediction Center
All 29 counties
Adair County, IA, Adams County, IA, Cass County, IA, Clarke County, IA, Dallas County, IA, Decatur County, IA, Guthrie County, IA, Jasper County, IA, Lucas County, IA, Madison County, IA, Marion County, IA, Monroe County, IA, Montgomery County, IA, Page County, IA, Polk County, IA, Ringgold County, IA, Taylor County, IA, Union County, IA, Warren County, IA, Wayne County, IA, Andrew County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Mercer County, MO, Nodaway County, MO, Worth County, MO
The radar
The Des Moines radar (KDMX), 112 km from the middle of the area, began a volume at 07:27 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 00:00Z, 7.4 hours before the alert went out and 188 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
- 1577 J/kg
- Mixed-layer CIN
- -12 J/kg
- Mixed-layer LCL
- 484 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 81 m²/s²
- 0-3 km storm-relative helicity
- 132 m²/s²
- Significant tornado parameter
- 0.7
- Supercell composite
- 3.4
The text
As transmitted, in the capitals the NWS used until 2016.
000 ACUS11 KWNS 250725 SWOMCD SPC MCD 250724 IAZ000-MOZ000-250830- MESOSCALE DISCUSSION 0721 NWS STORM PREDICTION CENTER NORMAN OK 0224 AM CDT FRI APR 25 2008 AREAS AFFECTED...SWRN IA AND NWRN MO CONCERNING...SEVERE THUNDERSTORM WATCH 228... VALID 250724Z - 250830Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 228 CONTINUES. REGIONAL RADARS INDICATED A BOWING STRUCTURE ACROSS FAR SWRN IA/ NWRN MO...EXTENDING FROM SRN MILLS COUNTY IA TO NODAWAY COUNTY MO. ADDITIONAL TSTMS HAVE ALSO DEVELOPED JUST DOWNSTREAM OF THE BOW IN TAYLOR/UNION COUNTIES IA...AND ACROSS MUCH OF CENTRAL IA...MAINLY N OF A WARM FRONT/OUTFLOW BOUNDARY THAT EXTENDED FROM SW-EAST CENTRAL IA. STRONG 70-80 KT SSWLY LLJ EXTENDING INTO NERN KS/NWRN MO TO SWRN IA WILL MAINTAIN MOISTURE/WARM AIR ADVECTION DOWNSTREAM OF THE BOWING STRUCTURE. GIVEN 60-70 KT WIND SPEEDS LOCATED JUST OFF THE SURFACE PER WIND PROFILER AT LTH AND KANSAS CITY WSR-88D...DAMAGING WINDS WILL BE LIKELY WITH ANY DOWNDRAFTS THAT PENETRATE TO THE SURFACE. ALTHOUGH THIS WIND DATA INDICATED A WEAKNESS IN SPEEDS IN THE 2-3 KM LAYER...WINDS IN THE 2-6 KM LAYER ARE EXPECTED TO STRENGTHEN THROUGH 12Z AS CENTRAL ROCKIES UPPER TROUGH ADVANCES EWD INTO THE CENTRAL PLAINS. THIS WOULD SUGGEST A POTENTIAL FOR SURFACE BASED OR NEAR-SURFACE BASED STORMS TO PRODUCE A THREAT FOR TORNADOES AS LOW LEVEL DIRECTIONAL SHEAR INCREASES. THESE TRENDS WILL CONTINUE TO BE MONITORED FOR ANY ADDITIONAL WATCHES THAT WOULD BE NEEDED. ..PETERS.. 04/25/2008 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...DMX...EAX...OAX... 39729457 40319531 41129562 41639483 41869447 41899265 41079281 39919326
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 25, 12:07 AM CDT | Severe Thunderstorm Watch | SPC | Adair, Adams, Cass, Clarke, Dallas, Decatur and 15 more | 7 hr |
| Apr 25, 12:55 AM CDT | Mesoscale Discussion | SPC | Page | 35 min |
| Apr 25, 1:13 AM CDT | Tornado Watch | SPC | Fremont, Montgomery, Page | 5 hr |
| Apr 25, 3:18 AM CDT | Mesoscale Discussion | SPC | Fremont, Montgomery, Page | 57 min |
| Apr 25, 4:22 AM CDT | Mesoscale Discussion | SPC | Appanoose, Benton, Cedar, Clarke, Clinton, Davis and 31 more | 23 min |
| Apr 25, 4:51 AM CDT | Severe Thunderstorm Watch | SPC | Appanoose, Benton, Black Hawk, Buchanan, Cedar, Clinton and 23 more | 5 hr |
| Apr 25, 9:10 AM CDT | Mesoscale Discussion | SPC | Clinton, Jackson, Scott | 65 min |
| Apr 25, 12:21 PM CDT | Mesoscale Discussion | SPC | Cedar, Clinton, Davis, Delaware, Des Moines, Henry and 14 more | 54 min |
| Apr 25, 1:27 PM CDT | Severe Thunderstorm Watch | SPC | Cedar, Clinton, Des Moines, Dubuque, Henry, Iowa and 12 more | 7 hr |
| Apr 25, 3:28 PM CDT | Mesoscale Discussion | SPC | Clinton, Louisa, Scott | 62 min |
| Apr 25, 3:41 PM CDT | Tornado Watch | SPC | Cedar, Clinton, Des Moines, Dubuque, Jackson, Jones and 4 more | 4 hr |
| Apr 25, 5:18 PM CDT | Mesoscale Discussion | SPC | Clinton, Louisa, Scott | 57 min |
| Apr 25, 6:01 PM CDT | Mesoscale Discussion | SPC | Clinton, Louisa, Scott | 59 min |
| Apr 25, 6:38 AM CDT | Mesoscale Discussion | SPC | Barton, Bates, Benton, Cass, Cedar, Clay and 16 more | 67 min |
| Apr 25, 2:15 PM CDT | Mesoscale Discussion | SPC | Barry, Camden, Christian, Dallas, Dent, Douglas and 13 more | 90 min |
| Apr 25, 6:40 PM CDT | Mesoscale Discussion | SPC | Butler, Carter, Oregon, Reynolds, Ripley, Shannon and 1 more | 65 min |
Nearby
Mesoscale Discussions in Iowa, 2008Mesoscale Discussions in Missouri, 2008Every mesoscale discussion in 2008
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.