Alert archive / Iowa / Mesoscale Discussions in 2024

Mesoscale Discussion 1621

July 14, 202421 counties in Illinois; 31 counties in Iowa; 7 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jul 14, 2024, 7:51 PM CDT for 21 counties in Illinois; 31 counties in Iowa; 7 counties in Wisconsin. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Jul 14, 2024, 7:51 PM CDT (00:51 UTC)
Expired
Jul 14, 2024, 9:15 PM CDT
In force
84 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 534
All 59 counties

Benton County, IA, Black Hawk County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Cedar County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Clayton County, IA, Clinton County, IA, Delaware County, IA, Dubuque County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Grundy County, IA, Hardin County, IA, Iowa County, IA, Jackson County, IA, Jasper County, IA, Johnson County, IA, Jones County, IA, Linn County, IA, Marshall County, IA, Muscatine County, IA, Polk County, IA, Poweshiek County, IA, Scott County, IA, Story County, IA, Tama County, IA, Worth County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, DeKalb County, IL, DuPage County, IL, Grundy County, IL, Henry County, IL, Jo Daviess County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, McHenry County, IL, Ogle County, IL, Rock Island County, IL, Stephenson County, IL, Whiteside County, IL, Will County, IL, Winnebago County, IL, Grant County, WI, Green County, WI, Iowa County, WI, Kenosha County, WI, Lafayette County, WI, Rock County, WI, Walworth County, WI

The radar

The Quad Cities radar (KDVN), 114 km from the middle of the area, began a volume at 00:54 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, 0.9 hours before the alert went out and 117 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 2024-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3951 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 2024-07-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 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
3951 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
993 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
1.7
Supercell composite
10.3

Open this sounding in Storm Lab

The text

As transmitted.

389 
ACUS11 KWNS 150051
SWOMCD
SPC MCD 150051 
ILZ000-WIZ000-IAZ000-150215-

Mesoscale Discussion 1621
NWS Storm Prediction Center Norman OK
0751 PM CDT Sun Jul 14 2024

Areas affected...Upper Midwest

Concerning...Severe Thunderstorm Watch 534...

Valid 150051Z - 150215Z

The severe weather threat for Severe Thunderstorm Watch 534
continues.

SUMMARY...Severe threat will spread across northern
Illinois/southern Wisconsin this evening.

DISCUSSION...Remnant MCV, from an early-day MCS, is moving
east-southeast across central IA. Latest radar/satellite imagery
suggests this long-lived feature is located northwest of CID. Over
the last hour or so, considerable amount of convection has
developed, possibly in response to this MCV. While a few supercells
are currently observed from southwest WI, arcing southwest along the
MS River through the middle portions of ww534, a new MCS may soon
evolve. This developing complex is expected to propagate toward
southern Lake MI with an attendant risk for hail/wind.

..Darrow.. 07/15/2024

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...LOT...MKX...DVN...ARX...DMX...

LAT...LON   43429365 42828780 41098780 41679366 43429365

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 14, 9:36 PM CDTMesoscale DiscussionSPCCook, DuPage, Kankakee, Kendall, Lake, Will54 min
Jul 14, 10:52 PM CDTMesoscale DiscussionSPCBureau, Ford, Grundy, Henry, Iroquois, Knox and 9 more83 min
Jul 14, 11:59 PM CDTSevere Thunderstorm WatchSPCChampaign, Coles, DeWitt, Douglas, Edgar, Logan and 4 more4 hr
Jul 15, 12:54 AM CDTMesoscale DiscussionSPCChampaign, DeWitt, Ford, Fulton, Grundy, Iroquois and 14 more2 hr
Jul 15, 1:59 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 32 more3 hr
Jul 15, 3:18 PM CDTSevere Thunderstorm WatchSPCBureau, Carroll, Fulton, Hancock, Henderson, Henry and 18 more8 hr
Jul 15, 5:26 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, DeKalb, Fulton, Hancock and 19 more2 hr
Jul 15, 6:06 PM CDTMesoscale DiscussionSPCBoone, Bureau, Champaign, Cook, DeKalb, DeWitt and 26 more114 min
Jul 15, 6:53 PM CDTTornado WatchSPCBoone, Bureau, Carroll, Cass, Champaign, Cook and 39 more6 hr
Jul 15, 6:55 PM CDTMesoscale DiscussionSPCBureau, Carroll, Henry, Knox, Lee, Mercer and 6 more95 min
Jul 15, 3:06 PM CDTMesoscale DiscussionSPCAshland, Bayfield, Burnett, Douglas, Florence, Forest and 8 more114 min

Nearby

Mesoscale Discussions in Iowa, 2024Mesoscale Discussions in Illinois, 2024Mesoscale Discussions in Wisconsin, 2024Every mesoscale discussion in 2024

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.