Alert archive / Minnesota / Mesoscale Discussions in 2018

Mesoscale Discussion 752

June 16, 201816 counties in Minnesota; 13 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 16, 2018, 3:06 PM CDT for 16 counties in Minnesota; 13 counties in South Dakota. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Jun 16, 2018, 3:06 PM CDT (20:06 UTC)
Expired
Jun 16, 2018, 4:30 PM CDT
In force
84 min
Issued by
the Storm Prediction Center
Chance of a watch
95%
All 29 counties

Big Stone County, MN, Chippewa County, MN, Douglas County, MN, Grant County, MN, Kandiyohi County, MN, Lac qui Parle County, MN, Lincoln County, MN, Lyon County, MN, Pope County, MN, Renville County, MN, Stearns County, MN, Stevens County, MN, Swift County, MN, Todd County, MN, Traverse County, MN, Yellow Medicine County, MN, Beadle County, SD, Brookings County, SD, Brown County, SD, Clark County, SD, Codington County, SD, Day County, SD, Deuel County, SD, Grant County, SD, Hamlin County, SD, Kingsbury County, SD, Marshall County, SD, Roberts County, SD, Spink County, SD

The radar

The Aberdeen radar (KABR), 142 km from the middle of the area, began a volume at 20:09 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 12:00Z, 8.1 hours before the alert went out and 142 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 12:00Z on 2018-06-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 177 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 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 12:00Z on 2018-06-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 283 square meters per square second.1939Sfc1 km3 km6 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
177 J/kg
Mixed-layer CIN
-361 J/kg
Mixed-layer LCL
1088 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
283 m²/s²
0-3 km storm-relative helicity
383 m²/s²
Significant tornado parameter
0.0
Supercell composite
9.2

Open this sounding in Storm Lab

The text

As transmitted.

930 
ACUS11 KWNS 162006
SWOMCD
SPC MCD 162006 
MNZ000-SDZ000-NDZ000-162130-

Mesoscale Discussion 0752
NWS Storm Prediction Center Norman OK
0306 PM CDT Sat Jun 16 2018

Areas affected...Portions of northeast SD...far southeast ND...and
western MN

Concerning...Severe potential...Tornado Watch likely 

Valid 162006Z - 162130Z

Probability of Watch Issuance...95 percent

SUMMARY...Scattered thunderstorms are expected to develop across the
area around 5-7pm CDT. A few of these storms will be severe, with an
attendant threat of a few tornadoes, damaging winds, and large hail.
A tornado watch will likely be issued by 4pm CDT.

DISCUSSION...Visible satellite imagery shows a cumulus field
expanding/spreading north across the region this afternoon, as the
boundary layer continues to warm/moisten behind earlier convection.
As weak mid-level ascent overspreads the eastern Dakotas from the
west and a low-level jet strengthens into early evening, scattered
thunderstorms are expected to develop along a front stretching from
northeast South Dakota east/northeast into central Minnesota. 

South of this front, very rich moisture and temps in the 80s are
combining with steep lapse rates aloft to yield around 2000-3000
J/kg of MLCAPE currently. Considerable veering of winds with height
will be favorable for supercells, capable of large hail, damaging
winds, and a few tornadoes. A strong tornado or two may be possible,
owing to ample storm-relative helicity accompanying the
strengthening low-level jet. This particular threat may be highly
regulated by RFD evolutions that are characteristic of HP
structures, owing to some weakness in mid-level storm-relative flow.
Regardless, a tornado watch will likely be issued by 4pm CDT.

..Picca/Grams.. 06/16/2018

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

ATTN...WFO...DLH...MPX...FGF...FSD...ABR...

LAT...LON   44209679 44259851 44799875 45559886 46069754 46509502
            46319459 45549439 44439510 44209679

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 16, 8:29 AM CDTMesoscale DiscussionSPCBecker, Beltrami, Clay, Clearwater, Douglas, Grant and 11 more2 hr
Jun 16, 3:38 PM CDTTornado WatchSPCBig Stone, Chippewa, Douglas, Grant, Kandiyohi, Lac qui Parle and 9 more8 hr
Jun 16, 6:21 PM CDTMesoscale DiscussionSPCBenton, Big Stone, Chippewa, Douglas, Grant, Kandiyohi and 13 more114 min
Jun 16, 9:13 AM CDTMesoscale DiscussionSPCBrown, Campbell, Corson, Dewey, Edmunds, Faulk and 4 more92 min
Jun 16, 3:15 PM CDTMesoscale DiscussionSPCBennett, Brule, Buffalo, Edmunds, Faulk, Haakon and 14 more90 min
Jun 16, 3:54 PM CDTSevere Thunderstorm WatchSPCBennett, Buffalo, Edmunds, Faulk, Haakon, Hand and 13 more7 hr
Jun 16, 6:14 PM CDTMesoscale DiscussionSPCBennett, Buffalo, Dewey, Edmunds, Faulk, Haakon and 14 more91 min

Nearby

Mesoscale Discussions in Minnesota, 2018Mesoscale Discussions in South Dakota, 2018Every mesoscale discussion in 2018

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.