Alert archive / Minnesota / Mesoscale Discussions in 2016

Mesoscale Discussion 1302

July 16, 201613 counties in Iowa; 23 counties in Minnesota; 5 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 16, 2016, 8:55 PM CDT for 13 counties in Iowa; 23 counties in Minnesota; 5 counties in South Dakota. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued: Jul 16, 2016, 8:55 PM CDT (01:55 UTC)
Expired: Jul 16, 2016, 10:30 PM CDT
In force: 95 min
Issued by: the Storm Prediction Center

All 41 counties

Cerro Gordo County, IA, Clay County, IA, Dickinson County, IA, Emmet County, IA, Hancock County, IA, Kossuth County, IA, Lyon County, IA, Mitchell County, IA, O'Brien County, IA, Osceola County, IA, Palo Alto County, IA, Winnebago County, IA, Worth County, IA, Blue Earth County, MN, Brown County, MN, Cottonwood County, MN, Dodge County, MN, Faribault County, MN, Freeborn County, MN, Jackson County, MN, Le Sueur County, MN, Lincoln County, MN, Lyon County, MN, Martin County, MN, Mower County, MN, Murray County, MN, Nicollet County, MN, Nobles County, MN, Pipestone County, MN, Rice County, MN, Rock County, MN, Scott County, MN, Sibley County, MN, Steele County, MN, Waseca County, MN, Watonwan County, MN, Brookings County, SD, Kingsbury County, SD, Lake County, SD, Minnehaha County, SD, Moody County, SD

The radar

The Sioux Falls radar (KFSD), 123 km from the middle of the area, began a volume at 01:54 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

Minneapolis, MN (KMPX), launched 00:00Z, 1.9 hours before the alert went out and 166 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: 4 J/kg
Mixed-layer CIN: -246 J/kg
Mixed-layer LCL: 1397 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 75 m²/s²
0-3 km storm-relative helicity: 190 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

054 
ACUS11 KWNS 170156
SWOMCD
SPC MCD 170155 
IAZ000-MNZ000-SDZ000-170330-

MESOSCALE DISCUSSION 1302
NWS STORM PREDICTION CENTER NORMAN OK
0855 PM CDT SAT JUL 16 2016

AREAS AFFECTED...EASTERN SD...SOUTHERN MN...NORTHERN IA

CONCERNING...SEVERE THUNDERSTORM WATCH 392...

VALID 170155Z - 170330Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 392
CONTINUES.

SUMMARY...ONGOING SEVERE STORM CLUSTERS FROM EAST-CENTRAL SD TO
SOUTHWEST MN WILL LIKELY MERGE INTO A BROADER CLUSTER THAT SHOULD
PROPAGATE SOUTHEASTWARD TOWARDS NORTHERN IA. DOWNSTREAM WW ISSUANCE
MAY BE NECESSARY BY 03-04Z.

DISCUSSION...LEAD STORM CLUSTER WITH A HISTORY OF MEASURED SEVERE
WINDS IS PROGRESSING SOUTHEAST ALONG THE MN RIVER VALLEY...WHILE A
SLOWER-MOVING SUPERCELL HAS PERSISTED ACROSS CLARK COUNTY SD WITH A
HISTORY OF LARGE HAIL AND A BRIEF TORNADO. CONVECTION IS INCREASING
BETWEEN THESE AREAS AS WELL AS SOUTHWARD ALONG THE MN/SD BORDER
WITHIN A 40-KT LLJ PER FSD VWP DATA. THIS LOW-LEVEL WAA REGIME
SHOULD FOSTER FURTHER CLUSTERING INTO A BROADER MCS AS INDIVIDUAL
UPDRAFTS AMALGAMATE. THIS MCS WILL LIKELY EVOLVE SOUTHEAST ALONG THE
CAPE GRADIENT EVIDENT IN OBJECTIVE ANALYSIS...AND SHOULD RESULT IN A
PRIMARY RISK OF SEVERE WIND DEVELOPING INTO PARTS OF NORTHERN IA AND
PERHAPS SOUTHEAST MN.

..GRAMS/WEISS.. 07/17/2016

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

ATTN...WFO...ARX...MPX...DMX...FSD...ABR...

LAT...LON   44569755 44659713 44389547 44399451 44789426 44659304
            44119254 43439247 42919314 42789405 42939580 43329674
            43769733 44139759 44569755

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 17, 2:06 AM CDT	Mesoscale Discussion	SPC	Audubon, Black Hawk, Boone, Bremer, Buena Vista, Butler and 32 more	2 hr
Jul 17, 7:00 AM CDT	Mesoscale Discussion	SPC	Des Moines, Henry, Louisa	2 hr
Jul 17, 2:35 PM CDT	Mesoscale Discussion	SPC	Cook, Lake	115 min
Jul 16, 7:07 PM CDT	Mesoscale Discussion	SPC	Bennett, Dewey, Haakon, Hughes, Hyde, Jackson and 11 more	83 min
Jul 16, 10:53 PM CDT	Mesoscale Discussion	SPC	Brown, Day, Edmunds, Faulk, McPherson, Marshall and 1 more	67 min

Nearby

Mesoscale Discussions in Minnesota, 2016 Mesoscale Discussions in Iowa, 2016 Mesoscale Discussions in South Dakota, 2016 Every mesoscale discussion in 2016

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.