Alert archive / Iowa / Mesoscale Discussions in 2012

Mesoscale Discussion 893

May 24, 201230 counties in Iowa; 6 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at May 24, 2012, 5:42 PM CDT for 30 counties in Iowa; 6 counties in Wisconsin. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 24, 2012, 5:42 PM CDT (22:42 UTC)
Expired
May 24, 2012, 7:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 36 counties

Allamakee County, IA, Appanoose County, IA, Benton County, IA, Black Hawk County, IA, Buchanan County, IA, Cedar County, IA, Clayton County, IA, Davis County, IA, Delaware County, IA, Des Moines County, IA, Dubuque County, IA, Fayette County, IA, Henry County, IA, Iowa County, IA, Jackson County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Mahaska County, IA, Monroe County, IA, Muscatine County, IA, Poweshiek County, IA, Tama County, IA, Van Buren County, IA, Wapello County, IA, Washington County, IA, Crawford County, WI, Grant County, WI, Iowa County, WI, Lafayette County, WI, Richland County, WI, Sauk County, WI

The radar

The Quad Cities radar (KDVN), 114 km from the middle of the area, began a volume at 22:42 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, 10.7 hours before the alert went out and 120 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.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2012-05-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 2012-05-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 84 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
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

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

509 
ACUS11 KWNS 242242
SWOMCD
SPC MCD 242242 
WIZ000-ILZ000-IAZ000-250045-

MESOSCALE DISCUSSION 0893
NWS STORM PREDICTION CENTER NORMAN OK
0542 PM CDT THU MAY 24 2012

AREAS AFFECTED...ERN IA/SWRN WI/FAR NWRN IL

CONCERNING...SEVERE THUNDERSTORM WATCH 296...

VALID 242242Z - 250045Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 296
CONTINUES.

SUMMARY...BAND OF STRONG/ISOLATED SEVERE STORMS WILL CONTINUE MOVING
EWD -- WITH ASSOCIATED SEVERE HAIL/WIND POTENTIAL.

DISCUSSION...A BROKEN BAND OF STORMS CONTINUES CROSSING ERN IA AND
ADJACENT AREAS ATTM...AHEAD OF AN ADVANCING COLD FRONT.  STORMS ARE
MOVING THROUGH THE AXIS OF GREATEST INSTABILITY ATTM...WITH A MUCH
MORE STABLE/CAPPED AIRMASS INDICATED E OF THE MS RIVER.  WHILE THIS
-- COMBINED WITH THE ONSET OF DIURNAL COOLING LATER THIS EVENING --
SHOULD RESULT IN AN EVENTUAL DECREASE IN STORM INTENSITY...THREAT
FOR LARGE HAIL AND LOCALLY DAMAGING GUSTS WILL CONTINUE FOR AT LEAST
A FEW MORE HOURS...WITHIN STRONGLY SHEARED/AMPLY UNSTABLE
ENVIRONMENT.

..GOSS.. 05/24/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...MKX...DVN...ARX...DMX...

LAT...LON   40609334 42669231 43499142 43478964 40629131 40609334

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 23, 8:56 PM CDTMesoscale DiscussionSPCAudubon, Buena Vista, Calhoun, Carroll, Cass, Cherokee and 23 more94 min
May 24, 6:33 AM CDTMesoscale DiscussionSPCAllamakee, Black Hawk, Bremer, Buchanan, Chickasaw, Clayton and 8 more57 min
May 24, 1:34 PM CDTMesoscale DiscussionSPCAllamakee, Black Hawk, Bremer, Butler, Cerro Gordo, Chickasaw and 10 more116 min
May 24, 3:06 PM CDTMesoscale DiscussionSPCAllamakee, Appanoose, Benton, Black Hawk, Bremer, Buchanan and 38 more114 min
May 24, 3:30 PM CDTSevere Thunderstorm WatchSPCAllamakee, Appanoose, Benton, Black Hawk, Bremer, Buchanan and 39 more4 hr
May 24, 2:22 PM CDTTornado WatchSPCAdams, Ashland, Barron, Bayfield, Buffalo, Chippewa and 27 more5 hr
May 24, 5:41 PM CDTMesoscale DiscussionSPCAdams, Clark, Eau Claire, Florence, Forest, Iron and 15 more2 hr

Nearby

Mesoscale Discussions in Iowa, 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.