Alert archive / Iowa / Mesoscale Discussions in 2020

Mesoscale Discussion 256

March 28, 202013 counties in Illinois; 22 counties in Iowa; Clark County, Missouri

The Storm Prediction Center issued this mesoscale discussion at Mar 28, 2020, 5:21 PM CDT for 13 counties in Illinois; 22 counties in Iowa; Clark County, Missouri. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Mar 28, 2020, 5:21 PM CDT (22:21 UTC)
Expired
Mar 28, 2020, 6:45 PM CDT
In force
84 min
Issued by
the Storm Prediction Center
All 36 counties

Benton County, IA, Black Hawk County, IA, Buchanan County, IA, Cedar County, IA, Clinton County, IA, Delaware County, IA, Des Moines County, IA, Henry County, IA, Iowa County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Muscatine County, IA, Poweshiek County, IA, Scott County, IA, Tama County, IA, Van Buren County, IA, Washington County, IA, Brown County, IL, Fulton County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Knox County, IL, McDonough County, IL, Mercer County, IL, Peoria County, IL, Rock Island County, IL, Schuyler County, IL, Stark County, IL, Warren County, IL, Clark County, MO

The radar

The Quad Cities radar (KDVN), 95 km from the middle of the area, began a volume at 22:23 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, 10.4 hours before the alert went out and 101 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 2020-03-28Temperature 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 2020-03-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -128 square meters per square second.1939587897117136Sfc1 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
695 m above ground
0-6 km bulk shear
72 kt
0-1 km storm-relative helicity
-128 m²/s²
0-3 km storm-relative helicity
164 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
Mar 27, 8:02 PM CDTMesoscale DiscussionSPCEdwards, Franklin, Hamilton, Jackson, Jefferson, Lawrence and 10 more88 min
Mar 27, 8:33 PM CDTMesoscale DiscussionSPCCalhoun87 min
Mar 27, 10:16 PM CDTSevere Thunderstorm WatchSPCBond, Calhoun, Christian, Effingham, Fayette, Greene and 9 more6 hr
Mar 27, 11:46 PM CDTMesoscale DiscussionSPCBond, Calhoun, Christian, Fayette, Greene, Jersey and 8 more89 min
Mar 28, 1:34 AM CDTMesoscale DiscussionSPCCarroll, Henry, Jo Daviess, Mercer, Rock Island, Whiteside56 min
Mar 28, 10:18 AM CDTMesoscale DiscussionSPCChampaign, Christian, DeWitt, Douglas, Ford, Iroquois and 8 more2 hr
Mar 28, 1:17 PM CDTMesoscale DiscussionSPCAlexander, Bond, Clark, Clay, Clinton, Crawford and 34 more88 min
Mar 28, 1:33 PM CDTMesoscale DiscussionSPCAdams, Hancock, Henderson117 min
Mar 28, 2:45 PM CDTTornado Watch PDSSPCAdams, Brown, Bureau, Calhoun, Cass, Champaign and 44 more6 hr
Mar 28, 3:53 PM CDTTornado WatchSPCAlexander, Bond, Clark, Clay, Clinton, Crawford and 30 more5 hr
Mar 28, 4:59 PM CDTMesoscale DiscussionSPCGallatin, Hamilton, Hardin, Johnson, Massac, Pope and 2 more61 min
Mar 28, 6:42 PM CDTMesoscale DiscussionSPCCarroll, Jo Daviess, Stephenson93 min
Mar 28, 7:05 AM CDTMesoscale DiscussionSPCBarry, Barton, Bates, Benton, Boone, Camden and 27 more85 min
Mar 28, 2:10 PM CDTTornado WatchSPCDunklin, Pemiscot5 hr
Mar 28, 2:56 PM CDTMesoscale DiscussionSPCDunklin, Pemiscot94 min
Mar 28, 6:34 PM CDTTornado WatchSPCDunklin, Pemiscot7 hr

Nearby

Mesoscale Discussions in Iowa, 2020Mesoscale Discussions in Illinois, 2020Mesoscale Discussions in Missouri, 2020Every mesoscale discussion in 2020

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.