Alert archive / Illinois / Mesoscale Discussions in 2014

Mesoscale Discussion 1104

June 21, 20144 states

The Storm Prediction Center issued this mesoscale discussion at Jun 21, 2014, 12:41 PM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jun 21, 2014, 12:41 PM CDT (17:41 UTC)
Expired
Jun 21, 2014, 2:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
60%
All 53 counties

Cedar County, IA, Clinton County, IA, Des Moines County, IA, Henry County, IA, Jackson County, IA, Lee County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Adams County, IL, Boone County, IL, Brown County, IL, Bureau County, IL, Carroll County, IL, Cass County, IL, DeKalb County, IL, Fulton County, IL, Grundy County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, Kane County, IL, Kendall County, IL, Knox County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Logan County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, McHenry County, IL, Menard County, IL, Mercer County, IL, Ogle County, IL, Peoria County, IL, Pike County, IL, Putnam County, IL, Rock Island County, IL, Schuyler County, IL, Stark County, IL, Stephenson County, IL, Tazewell County, IL, Warren County, IL, Whiteside County, IL, Winnebago County, IL, Woodford County, IL, Clark County, MO, Lewis County, MO, Marion County, MO, Green County, WI, Rock County, WI

The radar

The Quad Cities radar (KDVN), 55 km from the middle of the area, began a volume at 17:42 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, 5.7 hours before the alert went out and 53 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 2014-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1411 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 2014-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -32 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
1411 J/kg
Mixed-layer CIN
-82 J/kg
Mixed-layer LCL
1067 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-32 m²/s²
0-3 km storm-relative helicity
-25 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.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 21, 1:33 PM CDTSevere Thunderstorm WatchSPCAdams, Boone, Brown, Bureau, Calhoun, Carroll and 57 more7 hr
Jun 21, 3:41 PM CDTMesoscale DiscussionSPCAdams, Boone, Brown, Bureau, Carroll, Cass and 42 more64 min
Jun 21, 6:16 PM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Bureau, Calhoun, Cass and 52 more89 min
Jun 20, 8:29 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Calhoun, Carroll, Cass and 15 more91 min
Jun 20, 8:51 PM CDTSevere Thunderstorm WatchSPCAdair, Adams, Cass, Fremont, Mills, Montgomery and 4 more6 hr
Jun 20, 11:28 PM CDTMesoscale DiscussionSPCAdair, Adams, Cass, Decatur, Fremont, Harrison and 8 more92 min
Jun 21, 1:57 AM CDTMesoscale DiscussionSPCAdams, Fremont, Mills, Montgomery, Page, Ringgold and 2 more63 min

Nearby

Mesoscale Discussions in Illinois, 2014Mesoscale Discussions in Iowa, 2014Mesoscale Discussions in Missouri, 2014Every mesoscale discussion in 2014

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.