Alert archive / South Dakota / Severe Thunderstorm Watches in 2015

Severe Thunderstorm Watch 458

July 27, 201523 counties in North Dakota; 27 counties in South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Jul 27, 2015, 10:49 PM CDT for 23 counties in North Dakota; 27 counties in South Dakota. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jul 27, 2015, 10:49 PM CDT (03:49 UTC)
Expired
Jul 28, 2015, 3:51 AM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
65 kt
All 50 counties

Barnes County, ND, Benson County, ND, Bottineau County, ND, Cavalier County, ND, Dickey County, ND, Eddy County, ND, Foster County, ND, Griggs County, ND, Kidder County, ND, LaMoure County, ND, Logan County, ND, McHenry County, ND, McIntosh County, ND, Nelson County, ND, Pierce County, ND, Ramsey County, ND, Ransom County, ND, Rolette County, ND, Sargent County, ND, Sheridan County, ND, Stutsman County, ND, Towner County, ND, Wells County, ND, Aurora County, SD, Beadle County, SD, Brown County, SD, Brule County, SD, Buffalo County, SD, Charles Mix County, SD, Clark County, SD, Codington County, SD, Davison County, SD, Day County, SD, Douglas County, SD, Edmunds County, SD, Faulk County, SD, Gregory County, SD, Hamlin County, SD, Hand County, SD, Hanson County, SD, Hutchinson County, SD, Jerauld County, SD, Kingsbury County, SD, Lake County, SD, Marshall County, SD, McCook County, SD, McPherson County, SD, Miner County, SD, Sanborn County, SD, Spink County, SD

The radar

The Bismarck radar (KBIS), 109 km from the middle of the area, began a volume at 03:49 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
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 27, 11:56 PM CDTSevere Thunderstorm WarningABRBuffalo, Hand, Hughes, Hyde, Lyman49 min
Jul 28, 12:07 AM CDTSevere Thunderstorm WarningFSDAurora, Brule, Charles Mix, Gregory, Jerauld38 min
Jul 28, 12:40 AM CDTSevere Thunderstorm WarningFSDAurora, Beadle, Brule, Jerauld50 min
Jul 28, 12:41 AM CDTSevere Thunderstorm WarningABRBuffalo, Faulk, Hand, Hyde, Spink49 min
Jul 28, 1:00 AM CDTSevere Thunderstorm WarningABRBrown, Edmunds, McPherson60 min
Jul 28, 1:23 AM CDTSevere Thunderstorm WarningABRClark, Day, Spink56 min
Jul 28, 1:50 AM CDTSevere Thunderstorm WarningFSDAurora, Charles Mix, Douglas, Gregory18 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

Bismarck Municip, ND (KBIS), launched 00:00Z, 3.8 hours before the alert went out and 104 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, Bismarck Municip, ND at 00:00Z on 2015-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1379 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, Bismarck Municip, ND at 00:00Z on 2015-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -14 square meters per square second.19395878Sfc1 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
1379 J/kg
Mixed-layer CIN
-136 J/kg
Mixed-layer LCL
2017 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
-14 m²/s²
0-3 km storm-relative helicity
40 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
Jul 28, 1:57 AM CDTMesoscale DiscussionSPCLyon, Sioux2 hr
Jul 28, 3:37 AM CDTMesoscale DiscussionSPCDickinson, Lyon, O'Brien, Osceola, Plymouth, Sioux2 hr
Jul 28, 3:40 PM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Audubon, Cass, Clarke and 25 more2 hr
Jul 28, 5:46 PM CDTSevere Thunderstorm WatchSPCAdair, Adams, Appanoose, Cass, Clarke, Davis and 28 more6 hr
Jul 27, 7:31 PM CDTSevere Thunderstorm WatchSPCAdams, Billings, Bowman, Burke, Burleigh, Divide and 17 more7 hr
Jul 27, 9:19 PM CDTMesoscale DiscussionSPCAdams, Billings, Bowman, Divide, Dunn, Golden Valley and 12 more116 min
Jul 27, 9:41 PM CDTMesoscale DiscussionSPCDickey, LaMoure, McIntosh, Ransom, Sargent3 hr

Nearby

Severe Thunderstorm Watches in South Dakota, 2015Severe Thunderstorm Watches in North Dakota, 2015Every severe thunderstorm watch in 2015

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.