Alert archive / Minnesota / Mesoscale Discussions in 2018

Mesoscale Discussion 749

June 16, 201817 counties in Minnesota; Richland County, North Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 16, 2018, 8:29 AM CDT for 17 counties in Minnesota; Richland County, North Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jun 16, 2018, 8:29 AM CDT (13:29 UTC)
Expired
Jun 16, 2018, 10:30 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Becker County, MN, Beltrami County, MN, Clay County, MN, Clearwater County, MN, Douglas County, MN, Grant County, MN, Hubbard County, MN, Koochiching County, MN, Lake of the Woods County, MN, Mahnomen County, MN, Norman County, MN, Otter Tail County, MN, Red Lake County, MN, Stevens County, MN, Traverse County, MN, Wadena County, MN, Wilkin County, MN, Richland County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 128 km from the middle of the area, began a volume at 13:29 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

International Fa, MN (KINL), launched 12:00Z, 1.5 hours before the alert went out and 254 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, International Fa, MN at 12:00Z on 2018-06-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1060 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, International Fa, MN at 12:00Z on 2018-06-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -78 square meters per square second.193958Sfc1 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
1060 J/kg
Mixed-layer CIN
-274 J/kg
Mixed-layer LCL
548 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
-78 m²/s²
0-3 km storm-relative helicity
54 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.9

Open this sounding in Storm Lab

The text

As transmitted.

350 
ACUS11 KWNS 161330
SWOMCD
SPC MCD 161329 
MNZ000-SDZ000-NDZ000-161530-

Mesoscale Discussion 0749
NWS Storm Prediction Center Norman OK
0829 AM CDT Sat Jun 16 2018

Areas affected...Portions of Minnesota and extreme southeast North
Dakota

Concerning...Severe potential...Watch unlikely 

Valid 161329Z - 161530Z

Probability of Watch Issuance...20 percent

SUMMARY...A line of strong to locally severe storms may continue
north/northeast through at least 10am CDT, posing a threat of a few
strong/damaging gusts and perhaps isolated hail reports. However,
due to the localized nature of the threat and uncertainty regarding
the persistence of the line, watch issuance is not currently
expected.

DISCUSSION...A leading line/trailing stratiform convective system
has organized across parts of North Dakota and Minnesota this
morning and is progressing north/northeast around 35 kt. Although
12Z soundings and mesoanalysis suggest notable mixed-layer
inhibition is present, low-level stability does not appear large
enough to prevent stronger downdraft momentum from reaching the
surface. Recent observed gusts around 45-55 mph seem to confirm this
thinking. 

The presence of aforementioned convective inhibition casts some
uncertainty on the maintenance of this system, but steep mid-level
lapse rates, ample effective shear, and northeasterly low-level flow
(i.e., into the line) may maintain convective intensity through
mid/late morning. The strongest cells, capable of locally damaging
winds and perhaps isolated severe hail, would likely be focused
along a theta-e ridge axis from west-central to north-central
Minnesota. Nonetheless, watch issuance is not currently anticipated
due to uncertainty regarding the persistence/organization of this
threat.

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

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

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

LAT...LON   46059723 46509741 47079707 47909620 48659539 48789496
            48749462 48509361 47549402 46619467 45819501 45509572
            45779683 45919705 46059723

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 16, 3:06 PM CDTMesoscale DiscussionSPCBig Stone, Chippewa, Douglas, Grant, Kandiyohi, Lac qui Parle and 10 more84 min
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 DiscussionSPCDickey, Emmons, LaMoure, Logan, McIntosh92 min

Nearby

Mesoscale Discussions in Minnesota, 2018Mesoscale Discussions in North 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.