Alert archive / Iowa / Mesoscale Discussions in 2015

Mesoscale Discussion 1313

July 6, 20156 counties in Iowa; Nobles County, Rock County, Minnesota; 4 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 6, 2015, 1:01 AM CDT for 6 counties in Iowa; Nobles County, Rock County, Minnesota; 4 counties in South Dakota. It was in force for 29 min.

The area

The outline as issued.

The facts

Issued: Jul 6, 2015, 1:01 AM CDT (06:01 UTC)
Expired: Jul 6, 2015, 1:30 AM CDT
In force: 29 min
Issued by: the Storm Prediction Center

Counties Dickinson County, IA, Lyon County, IA, O'Brien County, IA, Osceola County, IA, Plymouth County, IA, Sioux County, IA, Nobles County, MN, Rock County, MN, Clay County, SD, Lincoln County, SD, Turner County, SD, Union County, SD

The radar

The Sioux Falls radar (KFSD), 53 km from the middle of the area, began a volume at 06:01 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 nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 6.0 hours before the alert went out and 218 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2259 J/kg
Mixed-layer CIN: -104 J/kg
Mixed-layer LCL: 1549 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 97 m²/s²
0-3 km storm-relative helicity: 341 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 26.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

113 
ACUS11 KWNS 060601
SWOMCD
SPC MCD 060601 
MNZ000-IAZ000-SDZ000-NEZ000-060630-

MESOSCALE DISCUSSION 1313
NWS STORM PREDICTION CENTER NORMAN OK
0101 AM CDT MON JUL 06 2015

AREAS AFFECTED...SERN SD / NWRN IA / EXTREME SWRN MN

CONCERNING...SEVERE THUNDERSTORM WATCH 393...

VALID 060601Z - 060630Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 393
CONTINUES.

SUMMARY...THE WIND DAMAGE THREAT MAY EXTEND BEYOND THE ERN BOUND OF
SEVERE WATCH 393.

DISCUSSION...KFSD RADAR SHOWED RAPID TORNADOGENESIS WITH A
MESOVORTEX AROUND 0520Z /PER 50 KT ROTATIONAL VELOCITY AND CC
MINIMUM/ AS A GUST FRONT FROM LEADING CONVECTION OVER SWRN MN/SERN
SD INTERSECTED THE BOWING SEGMENT.  THE OVERALL CONVECTIVE
ORGANIZATION IS PARTLY ASSOCIATED WITH A WELL-DEVELOPED MCV IN THE
TRAILING STRATIFORM REGION NEAR THE KEYA PAHA COUNTY NEB/TRIPP
COUNTY SD BORDER.  AS THE COLD POOL CONTINUES TO MOVE E/SEWD ACROSS
THE TRI-STATE AREA...AN APPRECIABLY MOIST BOUNDARY LAYER /SURFACE
DEWPOINTS IN THE LOWER 70S/ AMIDST A VEERING FLOW REGIME WILL
SUPPORT THE NOTION FOR ADDITIONAL STRONG TO SEVERE STORM ACTIVITY. 
THE PRIMARY WIND DAMAGE RISK WILL LIKELY BE ASSOCIATED WITH THE
BOWING SEGMENT AND ANY SUBSEQUENT MESOVORTICES THAT MANAGE TO
DEVELOP.  AS A RESULT OF THIS EXPECTED RISK...A WATCH
EXTENSION-IN-AREA OR A NEW WATCH MAY BE NEEDED TO ADDRESS THE
EVOLVING THREAT.

..SMITH.. 07/06/2015

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...FSD...OAX...

LAT...LON   43519714 43709622 43819534 43349498 42879548 42719625
            42769726 43519714

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 5, 7:24 PM CDT	Mesoscale Discussion	SPC	Lyon, Osceola, Sioux	2 hr
Jul 5, 7:42 PM CDT	Severe Thunderstorm Watch	SPC	Buena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 5 more	8 hr
Jul 5, 9:57 PM CDT	Mesoscale Discussion	SPC	Lyon	2 hr
Jul 5, 7:04 PM CDT	Severe Thunderstorm Watch	SPC	Aitkin, Carlton, Cass, Crow Wing, Itasca, Pine and 1 more	4 hr
Jul 5, 9:34 PM CDT	Mesoscale Discussion	SPC	Aitkin, Carlton, Cass, Crow Wing, Saint Louis	86 min
Jul 5, 8:45 PM CDT	Mesoscale Discussion	SPC	Aurora, Beadle, Bennett, Brule, Buffalo, Charles Mix and 13 more	90 min

Nearby

Mesoscale Discussions in Iowa, 2015 Mesoscale Discussions in South Dakota, 2015 Mesoscale Discussions in Minnesota, 2015 Every mesoscale discussion in 2015

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.