Alert archive / South Dakota / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 69, NWS Rapid City, SD

July 4, 2017Pennington County, South Dakota

NWS Rapid City, SD issued this severe thunderstorm warning at Jul 4, 2017, 1:59 PM MDT for Pennington County, South Dakota. It was in force for 28 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 4, 2017, 1:59 PM MDT (19:59 UTC)
Expired
Jul 4, 2017, 2:27 PM MDT
In force
28 min
Issued by
NWS Rapid City, SD
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Pennington County, SD

The radar

The Rapid City radar (KUDX), 13 km from the middle of the area, began a volume at 20:02 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

Bismarck Municip, ND (KBIS), launched 12:00Z, 8.0 hours before the alert went out and 349 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 12:00Z on 2017-07-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1122 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 12:00Z on 2017-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 square meters per square second.1939Sfc1 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
1122 J/kg
Mixed-layer CIN
-283 J/kg
Mixed-layer LCL
1795 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
79 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Rapid City, SD wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 4, 11:00 AM MDT, 2 hours 59 minutes earlier.

Area forecast discussion, Jul 4, 11:00 AM MDT, 2 hours 59 minutes before
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Hazardous weather outlook, Jul 4, 2:27 AM MDT, 11 hours 32 minutes before
Hazardous Weather Outlook
National Weather Service Rapid City SD
227 AM MDT Tue Jul 4 2017

SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058-
071-051300-
Harding-Perkins-Butte-Northern Meade Co Plains-Ziebach-
Northern Black Hills-Northern Foot Hills-Rapid City-
Southern Foot Hills-Central Black Hills-Southern Black Hills-
Custer Co Plains-Pennington Co Plains-Haakon-Fall River-
Oglala Lakota-Jackson-Bennett-Mellette-Todd-Tripp-
Sturgis/Piedmont Foot Hills-Southern Meade Co Plains-
Hermosa Foot Hills-Northern Campbell-Southern Campbell-
Western Crook-Wyoming Black Hills-Weston-Northeastern Crook-
227 AM MDT Tue Jul 4 2017 /327 AM CDT Tue Jul 4 2017/

This Hazardous weather outlook is for western South Dakota and
Northeastern Wyoming.

.DAY ONE...Today and Tonight

Isolated to scattered thunderstorms are expected this afternoon
mainly across the Black Hills area and western South Dakota. A
few strong thunderstorms with small hail and gusty winds are
possible.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Hot and dry weather is expected this week. Daily minimum relative
humidities will average 15 to 25 percent. The warmest days will
be Wednesday and Thursday with temperatures reaching well into
the 90s to near 100. Elevated fire danger will result.

Isolated to scattered thunderstorms are also expected Thursday
into early next week. A few strong thunderstorms with small hail
and gusty winds are possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today.

&&

Stay tuned to NOAA weather radio for further updates...or check
our web site at weather.gov/rapidcity

In the hours before

Special weather statement, Jul 4, 1:46 PM MDT, 13 minutes before
Special Weather Statement
National Weather Service Rapid City SD
146 PM MDT TUE JUL 4 2017

SDZ024-026-028-072-042030-
Northern Black Hills SD-Central Black Hills SD-
Sturgis/Piedmont Foot Hills SD-Rapid City SD-
146 PM MDT TUE JUL 4 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN MEADE...SOUTHEASTERN
LAWRENCE AND CENTRAL PENNINGTON COUNTIES UNTIL 230 PM MDT...

At 145 PM MDT, Doppler radar was tracking a strong thunderstorm near
Johnson Siding, or 9 miles west of Rapid City, moving east at 15 mph.

Dime size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Southwestern Rapid City, Black Hawk, Summerset, Johnson Siding, Nemo,
Hisega and Pactola Reservoir.

This Includes Interstate 90 in South Dakota between Mile Markers 51
and 56.

LAT...LON 4410 10356 4422 10354 4416 10323 4397 10332
TIME...MOT...LOC 1945Z 288DEG 13KT 4413 10343

Pojorlie

The office that day

Everything else NWS Rapid City, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 3, 6:48 PM MDTSpecial Weather StatementUNRBennett57 min
Jul 4, 1:46 PM MDTSpecial Weather StatementUNRLawrence44 min
Jul 4, 2:22 PM MDTSpecial Weather StatementUNRPerkins38 min
Jul 4, 2:42 PM MDTSpecial Weather StatementUNRLawrence48 min
Jul 4, 3:12 PM MDTSpecial Weather StatementUNRPerkins48 min
Jul 4, 3:34 PM MDTSevere Thunderstorm WarningUNRMeade, Perkins, Ziebach56 min
Jul 4, 4:01 PM MDTSpecial Weather StatementUNRCuster44 min
Jul 4, 4:26 PM MDTSevere Thunderstorm WarningUNRMeade, Perkins, Ziebach49 min
Jul 4, 5:44 PM MDTSpecial Weather StatementUNRMeade46 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2017Every severe thunderstorm warning 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.