Alert archive / Iowa / Mesoscale Discussions in 2006

Mesoscale Discussion 521

April 15, 20065 counties in Illinois; 36 counties in Iowa; 7 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Apr 15, 2006, 10:46 PM CDT for 5 counties in Illinois; 36 counties in Iowa; 7 counties in Missouri. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued
Apr 15, 2006, 10:46 PM CDT (03:46 UTC)
Expired
Apr 16, 2006, 12:45 AM CDT
In force
119 min
Issued by
the Storm Prediction Center
All 48 counties

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, Delaware County, IA, Des Moines County, IA, Dubuque County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Grundy 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, Marshall County, IA, Muscatine County, IA, Poweshiek County, IA, Scott County, IA, Tama County, IA, Van Buren County, IA, Wapello County, IA, Washington County, IA, Hancock County, IL, Henderson County, IL, Mercer County, IL, Rock Island County, IL, Warren County, IL, Clark County, MO, Knox County, MO, Lewis County, MO, Marion County, MO, Monroe County, MO, Scotland County, MO, Shelby County, MO

The radar

The Quad Cities radar (KDVN), 136 km from the middle of the area, began a volume at 03:46 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 00:00Z, 3.8 hours before the alert went out and 143 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 00:00Z on 2006-04-16Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2006-04-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 190 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
2772 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
190 m²/s²
0-3 km storm-relative helicity
191 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.

000 
ACUS11 KWNS 160346
SWOMCD
SPC MCD 160346 
ILZ000-IAZ000-WIZ000-MOZ000-160545-

MESOSCALE DISCUSSION 0521
NWS STORM PREDICTION CENTER NORMAN OK
1046 PM CDT SAT APR 15 2006

AREAS AFFECTED...PORTIONS E-CENTRAL/SERN IA...NERN MO...EXTREME NWRN
IL.

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 160346Z - 160545Z

BAND OF STRONG-SEVERE TSTMS NOW OVER ERN-MOST PORTIONS WW 192 IS
EXPECTED TO LIFT NEWD TO AREA BETWEEN CID-UIN THROUGH APPROXIMATELY
7Z.  MAIN SEVERE POTENTIAL WILL TRANSITION TO HAIL...WITH OCCASIONAL
STRONG-SEVERE GUSTS ALSO POSSIBLE PARTICULARLY OVER MO.  AREA WILL
BE MONITORED FOR POSSIBLE WW.

VERTICAL SHEAR PROFILES ARE STRENGTHENING WITH TIME ACROSS THIS AREA
AS MID/UPPER LEVEL SPEED MAX APCHS...ASSOCIATED WITH NEARLY
VERTICALLY STACKED LOW OVER ERN NEB.  HOWEVER...GIVEN DECELERATION
OF THAT CYCLONE AND FCST MOTION OF MAIN BAND OF LOW LEVEL CONVECTIVE
FORCING...PRIND ACTIVITY WILL OUTRUN EWD SPREAD OF OPTIMAL
DEEP-LAYER SHEAR AS WELL.  INFLOW PARCELS ARE FCST TO BECOME MORE
ELEVATED OFF SFC WITH TIME AND WITH NWD EXTENT...GIVEN COMBINATION
OF DIABATIC SFC COOLING AND PRECIP COOLING OVER IA.  PARCELS MAY
REMAIN NEARLY SFC-BASED FOR ANOTHER FEW HOURS ACROSS PORTIONS NERN
MO...WHERE BOTH MUCAPE AND SEVERE POTENTIAL SHOULD BE MAXIMIZED. 
EFFECTIVE SHEARS 35-50 KT ARE EVIDENT IN RUC FCST SOUNDINGS BOTH FOR
CONVECTION ROOTED IN 800-900 MB LAYER OVER IA...AND ANYWHERE BETWEEN
SFC-850 MB ACROSS NERN MO.  MUCAPES 1000-1500 J/KG ARE EXPECTED.

..EDWARDS.. 04/16/2006

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

ATTN...WFO...ILX...LSX...DVN...ARX...DMX...EAX...

39289238 39849236 40049231 40539233 40749256 41079272
41529289 42019304 42869341 43339222 43239153 42539058
41929022 40909043 40489075 39419178 39249222

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 15, 11:39 PM CDTMesoscale DiscussionSPCAdams, Pike66 min
Apr 16, 7:15 AM CDTMesoscale DiscussionSPCGallatin, Hardin, Johnson, Massac, Pope, Saline2 hr
Apr 16, 10:57 AM CDTMesoscale DiscussionSPCAdams, Boone, Brown, Bureau, Calhoun, Carroll and 33 more2 hr
Apr 16, 11:17 AM CDTTornado WatchSPCAdams, Bond, Brown, Bureau, Calhoun, Cass and 44 more8 hr
Apr 16, 12:20 PM CDTSevere Thunderstorm WatchSPCBoone, Carroll, Cook, DeKalb, DuPage, Ford and 15 more7 hr
Apr 16, 1:08 PM CDTMesoscale DiscussionSPCChampaign, Clark, Crawford, Douglas, Edgar, Ford and 3 more97 min
Apr 16, 1:18 PM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Bureau, Calhoun, Cass and 45 more57 min
Apr 16, 1:39 PM CDTTornado WatchSPCChampaign, Clark, Coles, Crawford, Cumberland, Douglas and 11 more7 hr
Apr 16, 3:24 PM CDTMesoscale DiscussionSPCAlexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 13 more2 hr
Apr 16, 3:43 PM CDTMesoscale DiscussionSPCBond, Bureau, Cass, Champaign, Christian, Clark and 49 more92 min
Apr 16, 3:50 PM CDTMesoscale DiscussionSPCBoone, Cook, DeKalb, DuPage, Kane, Kendall and 6 more85 min
Apr 16, 6:14 PM CDTMesoscale DiscussionSPCChampaign, Clark, Clay, Coles, Crawford, Cumberland and 19 more2 hr
Apr 15, 9:14 PM CDTMesoscale DiscussionSPCAppanoose, Boone, Clarke, Dallas, Decatur, Greene and 10 more91 min

Nearby

Mesoscale Discussions in Iowa, 2006Mesoscale Discussions in Missouri, 2006Mesoscale Discussions in Illinois, 2006Every mesoscale discussion in 2006

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.