Alert archive / Iowa / Mesoscale Discussions in 2018

Mesoscale Discussion 918

June 28, 20185 counties in Illinois; 33 counties in Iowa; 19 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Jun 28, 2018, 10:57 AM CDT for 5 counties in Illinois; 33 counties in Iowa; 19 counties in Missouri. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jun 28, 2018, 10:57 AM CDT (15:57 UTC)
Expired
Jun 28, 2018, 1:00 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 57 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Boone County, IA, Carroll County, IA, Cass County, IA, Clarke County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Greene County, IA, Guthrie County, IA, Jasper County, IA, Jefferson County, IA, Keokuk County, IA, Lee County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Monroe County, IA, Montgomery County, IA, Polk County, IA, Ringgold County, IA, Shelby County, IA, Story County, IA, Taylor County, IA, Union County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Wayne County, IA, Adams County, IL, Brown County, IL, Hancock County, IL, Pike County, IL, Scott County, IL, Adair County, MO, Clark County, MO, Grundy County, MO, Harrison County, MO, Knox County, MO, Lewis County, MO, Linn County, MO, Macon County, MO, Marion County, MO, Mercer County, MO, Monroe County, MO, Pike County, MO, Putnam County, MO, Ralls County, MO, Schuyler County, MO, Scotland County, MO, Shelby County, MO, Sullivan County, MO, Worth County, MO

The radar

The Des Moines radar (KDMX), 137 km from the middle of the area, began a volume at 16:01 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, 4.0 hours before the alert went out and 236 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 2018-06-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 295 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 2018-06-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 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
295 J/kg
Mixed-layer CIN
-335 J/kg
Mixed-layer LCL
1054 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
63 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 28, 2:00 AM CDTMesoscale DiscussionSPCAlexander, Bond, Calhoun, Clinton, Franklin, Gallatin and 20 more3 hr
Jun 28, 8:43 AM CDTMesoscale DiscussionSPCAlexander, Bond, Calhoun, Clinton, Edwards, Franklin and 24 more62 min
Jun 28, 1:04 PM CDTSevere Thunderstorm WatchSPCAdams, Bond, Brown, Calhoun, Cass, Christian and 28 more7 hr
Jun 28, 3:34 PM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Christian and 47 more116 min
Jun 28, 5:33 PM CDTSevere Thunderstorm WatchSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 14 more7 hr
Jun 28, 7:20 AM CDTMesoscale DiscussionSPCAdair, Adams, Cass, Fremont, Harrison, Mills and 6 more2 hr
Jun 28, 8:12 AM CDTSevere Thunderstorm WatchSPCAdair, Adams, Appanoose, Audubon, Boone, Carroll and 28 more6 hr

Nearby

Mesoscale Discussions in Iowa, 2018Mesoscale Discussions in Missouri, 2018Mesoscale Discussions in Illinois, 2018Every mesoscale discussion in 2018

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.