Alert archive / North Dakota / Severe Thunderstorm Watches in 2016

Severe Thunderstorm Watch 471

September 7, 201611 counties in Minnesota; 15 counties in North Dakota; 13 counties in South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Sep 7, 2016, 3:19 PM CDT for 11 counties in Minnesota; 15 counties in North Dakota; 13 counties in South Dakota. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Sep 7, 2016, 3:19 PM CDT (20:19 UTC)
Expired
Sep 7, 2016, 9:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 39 counties

Becker County, MN, Big Stone County, MN, Clay County, MN, Grant County, MN, Hubbard County, MN, Mahnomen County, MN, Norman County, MN, Otter Tail County, MN, Traverse County, MN, Wadena County, MN, Wilkin County, MN, Barnes County, ND, Cass County, ND, Dickey County, ND, Emmons County, ND, Foster County, ND, Griggs County, ND, LaMoure County, ND, Logan County, ND, McIntosh County, ND, Ransom County, ND, Richland County, ND, Sargent County, ND, Steele County, ND, Stutsman County, ND, Traill County, ND, Brown County, SD, Clark County, SD, Codington County, SD, Day County, SD, Deuel County, SD, Edmunds County, SD, Faulk County, SD, Grant County, SD, Hamlin County, SD, Marshall County, SD, McPherson County, SD, Roberts County, SD, Spink County, SD

The radar

The Fargo/Grand Forks radar (KMVX), 121 km from the middle of the area, began a volume at 20:21 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
20%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Sep 7, 3:35 PM CDTSevere Thunderstorm WarningFGFRichland55 min
Sep 7, 3:57 PM CDTSevere Thunderstorm WarningFGFClay, Wilkin43 min
Sep 7, 6:42 PM CDTSevere Thunderstorm WarningABRFaulk, Spink48 min
Sep 7, 7:12 PM CDTSevere Thunderstorm WarningABRSpink33 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 8.3 hours before the alert went out and 183 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 2016-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Aberdeen, SD at 12:00Z on 2016-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 29 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1126 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
29 m²/s²
0-3 km storm-relative helicity
134 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 6, 8:16 PM CDTMesoscale DiscussionSPCHouston89 min
Sep 7, 2:11 PM CDTMesoscale DiscussionSPCBecker, Big Stone, Clay, Grant, Norman, Otter Tail and 3 more2 hr
Sep 7, 5:44 PM CDTMesoscale DiscussionSPCBecker, Big Stone, Clay, Douglas, Grant, Norman and 5 more61 min

Nearby

Severe Thunderstorm Watches in North Dakota, 2016Severe Thunderstorm Watches in South Dakota, 2016Severe Thunderstorm Watches in Minnesota, 2016Every severe thunderstorm watch 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.