Alert archive / South Dakota / Mesoscale Discussions in 2019

Mesoscale Discussion 1539

July 20, 20194 counties in Iowa; 13 counties in Minnesota; 23 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 20, 2019, 5:02 AM CDT for 4 counties in Iowa; 13 counties in Minnesota; 23 counties in South Dakota. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued
Jul 20, 2019, 5:02 AM CDT (10:02 UTC)
Expired
Jul 20, 2019, 6:30 AM CDT
In force
88 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 40 counties

Dickinson County, IA, Emmet County, IA, Lyon County, IA, Osceola County, IA, Brown County, MN, Cottonwood County, MN, Jackson County, MN, Lincoln County, MN, Lyon County, MN, Martin County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Redwood County, MN, Rock County, MN, Watonwan County, MN, Yellow Medicine County, MN, Aurora County, SD, Beadle County, SD, Brookings County, SD, Charles Mix County, SD, Clark County, SD, Davison County, SD, Deuel County, SD, Douglas County, SD, Gregory County, SD, Hamlin County, SD, Hanson County, SD, Hutchinson County, SD, Jerauld County, SD, Kingsbury County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Sanborn County, SD, Spink County, SD, Turner County, SD

The radar

The Sioux Falls radar (KFSD), 40 km from the middle of the area, began a volume at 10:00 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

Aberdeen, SD (KABR), launched 00:00Z, 10.0 hours before the alert went out and 176 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, Aberdeen, SD at 00:00Z on 2019-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 769 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, Aberdeen, SD at 00:00Z on 2019-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -86 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
769 J/kg
Mixed-layer CIN
-200 J/kg
Mixed-layer LCL
1190 m above ground
0-6 km bulk shear
70 kt
0-1 km storm-relative helicity
-86 m²/s²
0-3 km storm-relative helicity
118 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-4.3

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
Jul 20, 5:51 AM CDTSevere Thunderstorm WatchSPCClay, Dickinson, Lyon, O'Brien, Osceola, Sioux5 hr
Jul 20, 7:40 AM CDTMesoscale DiscussionSPCCerro Gordo, Chickasaw, Clay, Dickinson, Emmet, Floyd and 12 more95 min
Jul 20, 9:05 AM CDTSevere Thunderstorm WatchSPCAllamakee, Bremer, Butler, Cerro Gordo, Chickasaw, Clayton and 15 more7 hr
Jul 20, 10:05 AM CDTMesoscale DiscussionSPCBuena Vista, Butler, Cerro Gordo, Chickasaw, Emmet, Floyd and 14 more115 min
Jul 20, 4:40 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Boone, Carroll, Cass and 21 more95 min
Jul 20, 4:58 PM CDTSevere Thunderstorm WatchSPCAdair, Adams, Appanoose, Audubon, Cass, Cedar and 30 more5 hr
Jul 20, 6:54 PM CDTMesoscale DiscussionSPCAppanoose, Clarke, Davis, Decatur, Des Moines, Henry and 11 more66 min
Jul 20, 9:34 AM CDTMesoscale DiscussionSPCHouston, Winona116 min
Jul 19, 10:33 PM CDTMesoscale DiscussionSPCButte, Corson, Custer, Dewey, Fall River, Haakon and 15 more87 min
Jul 19, 11:48 PM CDTSevere Thunderstorm WatchSPCButte, Corson, Dewey, Edmunds, Faulk, Haakon and 12 more5 hr
Jul 20, 2:00 AM CDTMesoscale DiscussionSPCButte, Corson, Dewey, Haakon, Hughes, Lawrence and 4 more60 min
Jul 20, 4:02 AM CDTMesoscale DiscussionSPCEdmunds, Faulk, Haakon, Hand, Hughes, Hyde and 4 more58 min

Nearby

Mesoscale Discussions in South Dakota, 2019Mesoscale Discussions in Minnesota, 2019Mesoscale Discussions in Iowa, 2019Every mesoscale discussion in 2019

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.