Alert archive / Iowa / Mesoscale Discussions in 2012
Mesoscale Discussion 890
The Storm Prediction Center issued this mesoscale discussion at May 24, 2012, 3:06 PM CDT for 44 counties in Iowa; 4 counties in Missouri; 4 counties in Wisconsin. It was in force for 114 min.
The area
The outline as issued.
The facts
- Issued
- May 24, 2012, 3:06 PM CDT (20:06 UTC)
- Expired
- May 24, 2012, 5:00 PM CDT
- In force
- 114 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
All 52 counties
Allamakee County, IA, Appanoose County, IA, Benton County, IA, Black Hawk County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Cedar County, IA, Chickasaw County, IA, Clarke County, IA, Clayton County, IA, Decatur County, IA, Delaware County, IA, Dubuque County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Grundy County, IA, Hardin County, IA, Howard County, IA, Iowa County, IA, Jackson County, IA, Jasper County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Linn County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Mitchell County, IA, Monroe County, IA, Polk County, IA, Poweshiek County, IA, Ringgold County, IA, Story County, IA, Tama County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Winneshiek County, IA, Gentry County, MO, Harrison County, MO, Mercer County, MO, Worth County, MO, Crawford County, WI, Grant County, WI, Iowa County, WI, Richland County, WI
The radar
The Quad Cities radar (KDVN), 132 km from the middle of the area, began a volume at 20:06 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
Davenport, (KDVN), launched 12:00Z, 8.1 hours before the alert went out and 137 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1568 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 84 m²/s²
- 0-3 km storm-relative helicity
- 20 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
656
ACUS11 KWNS 242006
SWOMCD
SPC MCD 242006
WIZ000-ILZ000-IAZ000-MNZ000-MOZ000-242200-
MESOSCALE DISCUSSION 0890
NWS STORM PREDICTION CENTER NORMAN OK
0306 PM CDT THU MAY 24 2012
AREAS AFFECTED...PORTIONS ERN IA...EXTREME NRN MO...SWRN
WI...EXTREME NWRN IL -- S OF WW 295.
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 242006Z - 242200Z
PROBABILITY OF WATCH ISSUANCE...40 PERCENT
SUMMARY...CONVECTION IS INCREASING INVOF SFC COLD FRONT OVER
CENTRAL/SWRN IA AND OVER NWRN MO. POTENTIAL EXISTS FOR TSTMS TO
EVOLVE FROM SOME OF THIS ACTIVITY AND MOVE EWD ACROSS PORTIONS IA SW
OF WW 295. MAIN THREAT WILL BE DAMAGING GUSTS...WITH ISOLATED HAIL
ALSO POSSIBLE. WW APPEARS MORE PROBABLE IN NERN IA/SWRN WI VERSUS
ELSEWHERE IN DISCUSSION AREA.
DISCUSSION...AT 1945Z..SFC COLD FRONT EXTENDED SSWWD FROM SERN MN
LOW...ACROSS BOONE COUNTY IA TO BROWN COUNTY KS. FRONT SHOULD MOVE
EWD/SEWD ACROSS IA...IMPINGING ON WARM SECTOR THAT SHOULD CONTINUE
TO DESTABILIZE FOR ANOTHER COUPLE OF HOURS. CONVECTION WILL IMPINGE
ON NARROW CORRIDOR OF AT LEAST MRGLLY FAVORABLE WARM-SECTOR THETAE
OVER CENTRAL/SRN IA AND SWRN WI...SANDWICHED BETWEEN COLD FRONT AND
PLUME OF RELATIVE LOW-LEVEL DRYING FARTHER E THAT HAS BEEN INDICATED
PERSISTENTLY IN RAOB ANALYSES AND SATELLITE-DERIVED TOTAL-PW
IMAGERY. MODIFIED FCST SOUNDINGS SUGGEST MLCAPE 1000-1500 J/KG WITH
50-100 NM AHEAD OF FRONT...ATOP WELL-MIXED/INVERTED-V THERMODYNAMIC
PROFILE IN BOUNDARY LAYER. THIS REGIME...SET AMIDST 50-70 KT
EFFECTIVE SHEAR MAGNITUDE AND STG DEEP-LAYER WINDS ALIGNED NEARLY
PARALLEL TO FRONT...INDICATES QUASI-LINEAR CONVECTIVE MODE WITH
DAMAGING WIND POSSIBLE. STRONGEST MID-UPPER LEVEL SUPPORT AND
LOW-LEVEL FRONTAL ASCENT SHOULD REMAIN N OF MO THROUGH
AFTERNOON...WHILE CINH INCREASES WITH SWD EXTENT. THIS INDICATES
ANY CONVECTION S OF IA SHOULD REMAIN RELATIVELY SHORT-LIVED AND NOT
AS INTENSE AS FARTHER N.
..EDWARDS/WEISS.. 05/24/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MKX...DVN...ARX...DMX...EAX...
LAT...LON 43578991 42629016 42349029 41389134 40669271 39929513
41179413 42489337 43519301 43489122 43578991SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 23, 8:56 PM CDT | Mesoscale Discussion | SPC | Audubon, Buena Vista, Calhoun, Carroll, Cass, Cherokee and 23 more | 94 min |
| May 24, 6:33 AM CDT | Mesoscale Discussion | SPC | Allamakee, Black Hawk, Bremer, Buchanan, Chickasaw, Clayton and 8 more | 57 min |
| May 24, 1:34 PM CDT | Mesoscale Discussion | SPC | Allamakee, Black Hawk, Bremer, Butler, Cerro Gordo, Chickasaw and 10 more | 116 min |
| May 24, 3:30 PM CDT | Severe Thunderstorm Watch | SPC | Allamakee, Appanoose, Benton, Black Hawk, Bremer, Buchanan and 39 more | 4 hr |
| May 24, 5:42 PM CDT | Mesoscale Discussion | SPC | Allamakee, Appanoose, Benton, Black Hawk, Buchanan, Cedar and 24 more | 2 hr |
| May 24, 5:11 PM CDT | Mesoscale Discussion | SPC | Adair, Caldwell, Carroll, Chariton, Clay, Clinton and 22 more | 2 hr |
| May 24, 2:22 PM CDT | Tornado Watch | SPC | Adams, Ashland, Barron, Bayfield, Buffalo, Chippewa and 27 more | 5 hr |
| May 24, 5:41 PM CDT | Mesoscale Discussion | SPC | Adams, Clark, Eau Claire, Florence, Forest, Iron and 15 more | 2 hr |
Nearby
Mesoscale Discussions in Iowa, 2012Mesoscale Discussions in Missouri, 2012Mesoscale Discussions in Wisconsin, 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.