Alert archive / Minnesota / Mesoscale Discussions in 2017

Mesoscale Discussion 985

June 11, 201722 counties in Minnesota; 10 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2017, 5:51 AM CDT for 22 counties in Minnesota; 10 counties in Wisconsin. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Jun 11, 2017, 5:51 AM CDT (10:51 UTC)
Expired: Jun 11, 2017, 7:15 AM CDT
In force: 84 min
Issued by: the Storm Prediction Center
Chance of a watch: 95%

All 32 counties

Anoka County, MN, Brown County, MN, Carver County, MN, Chisago County, MN, Dakota County, MN, Goodhue County, MN, Hennepin County, MN, Isanti County, MN, Le Sueur County, MN, McLeod County, MN, Meeker County, MN, Nicollet County, MN, Ramsey County, MN, Rice County, MN, Scott County, MN, Sherburne County, MN, Sibley County, MN, Stearns County, MN, Wabasha County, MN, Washington County, MN, Watonwan County, MN, Wright County, MN, Barron County, WI, Buffalo County, WI, Chippewa County, WI, Dunn County, WI, Eau Claire County, WI, Pepin County, WI, Pierce County, WI, Polk County, WI, Rusk County, WI, Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 47 km from the middle of the area, began a volume at 10:53 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.

Severe Thunderstorm Watch 312Jun 11, 6:25 AM CDT

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 10.9 hours before the alert went out and 48 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: 1841 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1879 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 37 m²/s²
0-3 km storm-relative helicity: 126 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 4.0

Open this sounding in Storm Lab

The text

As transmitted.

162 
ACUS11 KWNS 111052
SWOMCD
SPC MCD 111051 
WIZ000-MNZ000-111215-

Mesoscale Discussion 0985
NWS Storm Prediction Center Norman OK
0551 AM CDT Sun Jun 11 2017

Areas affected...central and eastern parts of MN...west-central and
northwest WI

Concerning...Severe potential...Severe Thunderstorm Watch likely 

Valid 111051Z - 111215Z

Probability of Watch Issuance...95 percent

SUMMARY...A severe bow echo will likely move east of WW 311 and
reach the Minneapolis/Saint Paul metro around 9AM CDT.  Corridors of
50-70 mph gusts will yield scattered wind damage.  A new severe
thunderstorm watch will likely be issued by 7AM CDT.

DISCUSSION...Radar mosaic shows a maturing bow echo moving east
around 45 kt across eastern SD with a well-developed comma head and
rear inflow channel.  Very high echo tops (55k ft) associated with
the updrafts within the line indicate ample buoyancy and a
considerable amount of hydrometers suspended aloft which will
translate to severe gusts via 1) momentum transport 2) water
loading, and 3) evaporative cooling---which should enable stronger
downdrafts to punch higher momentum flow to the surface in the form
of 50-70 mph gusts.  It seems the concentration of wind
damage/severe gusts may preferentially favor the western half of the
discussion area as less moisture-rich air infiltrates western WI
prior to squall line passage.

..Smith/Thompson.. 06/11/2017

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

ATTN...WFO...DLH...ARX...MPX...

LAT...LON   45509509 45879279 45749065 44409074 43979468 45509509

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 11, 2:02 AM CDT	Mesoscale Discussion	SPC	Big Stone, Brown, Carver, Chippewa, Kandiyohi, Lac qui Parle and 15 more	58 min
Jun 11, 2:37 AM CDT	Severe Thunderstorm Watch	SPC	Big Stone, Brown, Chippewa, Cottonwood, Kandiyohi, Lac qui Parle and 10 more	5 hr
Jun 11, 4:00 AM CDT	Mesoscale Discussion	SPC	Lincoln, Lyon, Pipestone	60 min
Jun 11, 6:28 AM CDT	Severe Thunderstorm Watch	SPC	Anoka, Benton, Blue Earth, Carver, Chisago, Dakota and 26 more	6 hr
Jun 11, 9:30 AM CDT	Mesoscale Discussion	SPC	Anoka, Chisago, Dakota, Dodge, Fillmore, Goodhue and 10 more	60 min
Jun 11, 6:20 PM CDT	Mesoscale Discussion	SPC	Chisago, Dakota, Dodge, Goodhue, Olmsted, Ramsey and 3 more	2 hr
Jun 10, 8:12 PM CDT	Mesoscale Discussion	SPC	Barron, Chippewa, Dunn, Iron, Pepin, Pierce and 6 more	2 hr
Jun 11, 10:39 AM CDT	Severe Thunderstorm Watch	SPC	Brown, Calumet, Door, Florence, Forest, Kewaunee and 16 more	5 hr
Jun 11, 12:00 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Calumet, Clark, Door, Florence and 24 more	2 hr

Nearby

Mesoscale Discussions in Minnesota, 2017 Mesoscale Discussions in Wisconsin, 2017 Every mesoscale discussion in 2017

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.