Alert archive / Iowa / Mesoscale Discussions in 2011

Mesoscale Discussion 849

May 22, 20116 states

The Storm Prediction Center issued this mesoscale discussion at May 22, 2011, 10:53 AM CDT for 6 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 22, 2011, 10:53 AM CDT (15:53 UTC)
Expired
May 22, 2011, 1:00 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 115 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, Clayton County, IA, Clinton County, IA, Davis County, IA, Decatur County, IA, Delaware County, IA, Des Moines County, IA, Dubuque County, IA, Fayette County, IA, Floyd County, IA, Grundy County, IA, Henry County, IA, Howard County, IA, Iowa County, IA, Jackson County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Lucas County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Muscatine County, IA, Poweshiek County, IA, Scott County, IA, Tama County, IA, Van Buren County, IA, Wapello County, IA, Washington County, IA, Wayne County, IA, Winneshiek County, IA, Adams County, IL, Carroll County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, Knox County, IL, McDonough County, IL, Mercer County, IL, Rock Island County, IL, Stephenson County, IL, Warren County, IL, Whiteside County, IL, Anderson County, KS, Franklin County, KS, Johnson County, KS, Linn County, KS, Miami County, KS, Wyandotte County, KS, Houston County, MN, Adair County, MO, Audrain County, MO, Bates County, MO, Benton County, MO, Boone County, MO, Caldwell County, MO, Carroll County, MO, Cass County, MO, Chariton County, MO, Clark County, MO, Clay County, MO, Clinton County, MO, Cooper County, MO, Daviess County, MO, Grundy County, MO, Harrison County, MO, Henry County, MO, Howard County, MO, Jackson County, MO, Johnson County, MO, Knox County, MO, Lafayette County, MO, Lewis County, MO, Linn County, MO, Livingston County, MO, Macon County, MO, Marion County, MO, Mercer County, MO, Moniteau County, MO, Monroe County, MO, Morgan County, MO, Pettis County, MO, Putnam County, MO, Ralls County, MO, Randolph County, MO, Ray County, MO, Saline County, MO, Schuyler County, MO, Scotland County, MO, Shelby County, MO, St. Clair County, MO, Sullivan County, MO, Crawford County, WI, Grant County, WI, Green County, WI, Iowa County, WI, Lafayette County, WI, Richland County, WI, Sauk County, WI, Vernon County, WI

The radar

The Quad Cities radar (KDVN), 123 km from the middle of the area, began a volume at 15:54 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, 3.9 hours before the alert went out and 129 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 2011-05-22Temperature 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 2011-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 233 square meters per square second.1939587897Sfc1 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
1775 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
233 m²/s²
0-3 km storm-relative helicity
287 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.

772 
ACUS11 KWNS 221553
SWOMCD
SPC MCD 221553 
ILZ000-WIZ000-IAZ000-MOZ000-MNZ000-KSZ000-221800-

MESOSCALE DISCUSSION 0849
NWS STORM PREDICTION CENTER NORMAN OK
1053 AM CDT SUN MAY 22 2011

AREAS AFFECTED...MUCH OF ERN IA...NRN MO...NWRN IL...SWRN WI

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 

VALID 221553Z - 221800Z

CONDITIONS WILL BECOME QUITE FAVORABLE FOR SUPERCELLS AND TORNADOES
LATER THIS AFTERNOON...AND ONE OR MORE TORNADO WATCHES ARE LIKELY BY
MIDDAY.

VISIBLE SATELLITE IMAGERY SHOWS A WELL DEFINED DRYLINE ACROSS ERN
KS...NWRN MO AND INTO IA WHERE MORE EXTENSIVE CLOUD COVER EXISTED AS
A RESULT OF THE UPPER VORT. MEANWHILE...A PSEUDO-WARM FRONT
EXTENDING FROM CNTRL IA SEWD INTO CNTRL IL...WITH MID TO UPPER 60S F
DEWPOINTS S OF THIS BOUNDARY. 

MORNINGS SOUNDINGS SHOWED CLASSIC LOADED GUN WITH SUBSTANTIAL
BOUNDARY LAYER MOISTURE IN PLACE BENEATH A BREAKABLE CAPPING
INVERSION. THE STRONGEST FORCING FOR ASCENT WILL DEVELOP FIRST
ACROSS MN/IA/WI AS THE UPPER LOW CONTINUES EWD. NRN EXTENT OF THREAT
AREA WILL COINCIDE WITH WARM FRONT. OTHER DEVELOPMENT WILL OCCUR SWD
ALONG THE DRYLINE INTO MO AND FAR ERN KS WHERE A SUBSTANTIAL CU
FIELD WAS ALREADY DEVELOPING AND WITH 3000-4000 J/KG MUCAPE. SHEAR
PROFILES ARE FAVORABLE FOR SUPERCELLULAR STORM MODE CAPABLE OF A FEW
STRONG TORNADOES AND VERY LARGE HAIL.

..JEWELL.. 05/22/2011

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

ATTN...WFO...LOT...ILX...MKX...LSX...DVN...ARX...SGF...DMX...
EAX...TOP...ICT...

LAT...LON   42938956 42448947 41758955 40959003 40179073 38999185
            37979346 37929501 38019553 38329550 39859423 41649341
            42949303 43529242 43819145 43789045 43328958 42938956

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 22, 4:41 AM CDTMesoscale DiscussionSPCAdams, Boone, Brown, Bureau, Carroll, Cass and 37 more2 hr
May 22, 12:51 PM CDTTornado WatchSPCAdams, Bond, Brown, Bureau, Calhoun, Carroll and 42 more10 hr
May 22, 1:49 PM CDTMesoscale DiscussionSPCBoone, Cook, DeKalb, DuPage, Grundy, Kane and 10 more56 min
May 22, 2:04 PM CDTTornado WatchSPCBoone, Cook, DeKalb, DuPage, Ford, Grundy and 12 more9 hr
May 22, 2:59 PM CDTMesoscale DiscussionSPCJo Daviess2 hr
May 22, 4:16 PM CDTMesoscale DiscussionSPCChampaign, Douglas, Edgar, Ford, Iroquois, Kankakee and 2 more119 min
May 22, 5:47 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, DeKalb, DuPage, Grundy and 23 more88 min
May 21, 8:55 PM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Audubon, Black Hawk, Boone and 68 more65 min
May 22, 12:07 PM CDTTornado WatchSPCAllamakee, Chickasaw, Clayton, Fayette, Floyd, Howard and 2 more7 hr
May 21, 7:18 PM CDTMesoscale DiscussionSPCAtchison, Barton, Brown, Clay, Cloud, Dickinson and 30 more57 min
May 22, 1:06 PM CDTMesoscale DiscussionSPCBourbon, Chautauqua, Cherokee, Crawford, Labette, Montgomery and 2 more114 min
May 22, 1:27 PM CDTTornado WatchSPCAllen, Bourbon, Chautauqua, Cherokee, Crawford, Labette and 3 more8 hr
May 22, 3:48 PM CDTMesoscale DiscussionSPCCherokee, Crawford117 min
May 22, 6:10 PM CDTMesoscale DiscussionSPCCherokee, Crawford65 min
May 22, 3:43 PM CDTTornado WatchSPCPine5 hr
May 22, 5:18 AM CDTMesoscale DiscussionSPCDunklin, Pemiscot57 min

Nearby

Mesoscale Discussions in Iowa, 2011Mesoscale Discussions in Missouri, 2011Mesoscale Discussions in Illinois, 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.