Alert archive / North Dakota / Mesoscale Discussions in 2017

Mesoscale Discussion 974

June 9, 20177 counties in Minnesota; 22 counties in North Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 9, 2017, 3:26 PM CDT for 7 counties in Minnesota; 22 counties in North Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jun 9, 2017, 3:26 PM CDT (20:26 UTC)
Expired: Jun 9, 2017, 5:30 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 29 counties

Clay County, MN, Kittson County, MN, Marshall County, MN, Norman County, MN, Pennington County, MN, Polk County, MN, Red Lake County, MN, Barnes County, ND, Benson County, ND, Bottineau County, ND, Cass County, ND, Cavalier County, ND, Eddy County, ND, Foster County, ND, Grand Forks County, ND, Griggs County, ND, McHenry County, ND, Nelson County, ND, Pembina County, ND, Pierce County, ND, Ramsey County, ND, Rolette County, ND, Sheridan County, ND, Steele County, ND, Stutsman County, ND, Towner County, ND, Traill County, ND, Walsh County, ND, Wells County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 94 km from the middle of the area, began a volume at 20:27 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 309Jun 9, 4:55 PM CDT

The nearest sounding before it

Bismarck Municip, ND (KBIS), launched 12:00Z, 8.4 hours before the alert went out and 199 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1764 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 310 m²/s²
0-3 km storm-relative helicity: 390 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

592 
ACUS11 KWNS 092026
SWOMCD
SPC MCD 092026 
MNZ000-NDZ000-092230-

Mesoscale Discussion 0974
NWS Storm Prediction Center Norman OK
0326 PM CDT Fri Jun 09 2017

Areas affected...Northern and eastern North Dakota into northwest
Minnesota

Concerning...Severe potential...Watch likely 

Valid 092026Z - 092230Z

Probability of Watch Issuance...80 percent

SUMMARY...A cluster of thunderstorms is expected to form around 22Z
over north central North Dakota, and grow upscale into eastern North
Dakota into northwest Minnesota this evening. Large hail and
damaging winds are likely.

DISCUSSION...Visible imagery shows a CU field increasing in size and
depth near the warm front over northern ND, and extending southward
within the surface warm axis where temperatures have risen into the
mid 90s. Meanwhile, a weak surface low/trough will continue to
deepen and shift eastward with time, further increasing convergence.
This increasing lift and continued heating, combined with strong
warm advection should result in storm formation by around 22Z across
north central ND. The strong southerly low-level jet will favor a
southeastward storm motion via propagation, as cells grow upscale
with increasing damaging wind threat. Large boundary layer
temperature/dewpoint spreads as seen on 19Z BIS sounding should
further favor outflow production.

..Jewell/Hart.. 06/09/2017

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

ATTN...WFO...FGF...BIS...

LAT...LON   47600060 48210133 48730134 49060100 49069652 48709616
            48189604 47379602 46859637 46729690 46809800 46869879
            47199960 47600060

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 9, 4:58 PM CDT	Severe Thunderstorm Watch	SPC	Kittson, Marshall, Pennington, Polk, Red Lake	7 hr

Nearby

Mesoscale Discussions in North Dakota, 2017 Mesoscale Discussions in Minnesota, 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.