Alert archive / Iowa / Mesoscale Discussions in 2015

Mesoscale Discussion 246

April 9, 201514 counties in Illinois; 25 counties in Iowa; 11 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Apr 9, 2015, 12:29 PM CDT for 14 counties in Illinois; 25 counties in Iowa; 11 counties in Missouri. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
Apr 9, 2015, 12:29 PM CDT (17:29 UTC)
Expired
Apr 9, 2015, 2:00 PM CDT
In force
91 min
Issued by
the Storm Prediction Center
Chance of a watch
95%
All 50 counties

Appanoose County, IA, Cedar County, IA, Clinton County, IA, Davis County, IA, Des Moines 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, Marion County, IA, Monroe County, IA, Muscatine County, IA, Poweshiek County, IA, Scott County, IA, Van Buren County, IA, Wapello County, IA, Washington County, IA, Wayne County, IA, Bureau County, IL, Carroll County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, Knox County, IL, Lee County, IL, Mercer County, IL, Ogle County, IL, Rock Island County, IL, Stephenson County, IL, Warren County, IL, Whiteside County, IL, Winnebago County, IL, Adair County, MO, Clark County, MO, Grundy County, MO, Knox County, MO, Linn County, MO, Macon County, MO, Mercer County, MO, Putnam County, MO, Schuyler County, MO, Scotland County, MO, Sullivan County, MO

The radar

The Quad Cities radar (KDVN), 54 km from the middle of the area, began a volume at 17:29 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, 5.5 hours before the alert went out and 61 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 2015-04-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 101 joules per kilogram.LCLLFCEL10008507005003002001001 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 2015-04-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 323 square meters per square second.19395878Sfc1 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
101 J/kg
Mixed-layer CIN
-154 J/kg
Mixed-layer LCL
614 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
323 m²/s²
0-3 km storm-relative helicity
253 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.4

Open this sounding in Storm Lab

The text

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

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 8, 7:04 PM CDTMesoscale DiscussionSPCFranklin, Gallatin, Hardin, Jackson, Johnson, Pope and 3 more116 min
Apr 9, 12:58 PM CDTTornado WatchSPCAdams, Brown, Carroll, Hancock, Henderson, Henry and 8 more6 hr
Apr 9, 1:48 PM CDTTornado WatchSPCBoone, Bureau, Cass, Champaign, Christian, Cook and 36 more9 hr
Apr 9, 3:12 PM CDTMesoscale DiscussionSPCAdams, Boone, Brown, Bureau, Calhoun, Carroll and 51 more93 min
Apr 9, 3:45 PM CDTMesoscale DiscussionSPCAlexander, Bond, Clay, Clinton, Cumberland, Effingham and 25 more60 min
Apr 9, 4:40 PM CDTTornado WatchSPCBond, Calhoun, Clinton, Fayette, Greene, Jersey and 8 more6 hr
Apr 9, 6:04 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, Cass, DeKalb, DeWitt and 37 more86 min
Apr 9, 6:48 PM CDTTornado WatchSPCAlexander, Clark, Clay, Coles, Crawford, Cumberland and 26 more6 hr
Apr 9, 1:32 PM CDTMesoscale DiscussionSPCBarry, Barton, Benton, Camden, Cedar, Dade and 11 more118 min
Apr 9, 2:32 PM CDTSevere Thunderstorm WatchSPCBarry, Benton, Camden, Christian, Dade, Dallas and 22 more7 hr
Apr 9, 6:11 PM CDTMesoscale DiscussionSPCButler, Carter, Dunklin, Mississippi, New Madrid, Oregon and 5 more64 min
Apr 9, 6:32 PM CDTSevere Thunderstorm WatchSPCDunklin, Pemiscot5 hr

Nearby

Mesoscale Discussions in Iowa, 2015Mesoscale Discussions in Illinois, 2015Mesoscale Discussions in Missouri, 2015Every mesoscale discussion in 2015

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.