Alert archive / South Dakota / Tornado Warnings in 2020
Tornado Warning 10, NWS Rapid City, SD
NWS Rapid City, SD issued this tornado warning at Aug 4, 2020, 6:39 PM CDT for Tripp County, South Dakota. It was in force for 51 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
- Aug 4, 2020, 6:39 PM CDT (23:39 UTC)
- Expired
- Aug 4, 2020, 7:30 PM CDT
- In force
- 51 min
- Issued by
- NWS Rapid City, SD
- Area
- Storm-based polygon
- Tornado
- Radar indicated
- Hail
- 1.5 in
County Tripp County, SD
The radar
The North Platte radar (KLNX), 164 km from the middle of the area, began a volume at 23:42 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
N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 11.7 hours before the alert went out and 253 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1267 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- 106 m²/s²
- 0-3 km storm-relative helicity
- 168 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.1
What forecasters said that day
The local office's own words before this tornado 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 tornado warning went out at Aug 4, 5:55 PM CDT, 44 minutes earlier.
Area forecast discussion, Aug 4, 5:55 PM CDT, 44 minutes before
Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 455 PM MDT Tue Aug 4 2020 .DISCUSSION...(This Evening Through Tuesday) Issued at 119 PM MDT Tue Aug 4 2020 Upper level analysis shows compact shortwave pushing eastward across southern Saskatchewan with trough axis extending southward into the northern plains. Surface trough axis extends from developing low pressure across NE Colorado this afternoon. Modest MUCAPE (1000-2500 J/kg) will be in place this afternoon and evening, although shear will be marginal. Broad upper level ascent via shortwave trough coupled with convergent flow along the southern Black Hills will provide impetus for thunderstorm development. The overall environment will be conducive to a few strong to severe storms through the evening before tapering off later tonight. Widespread severe weather is not anticipated this evening. Northwest flow continues Wednesday with chances for a storm or two through the day Wednesday, mainly across SW SD, although the best chances will remain to our northeast and south of the forecast area. Mid-level warm air advection spreads into the northern Plains overnight Wednesday as upper level ridge builds Thursday into Friday. Temperatures will warm back into the upper 80s to 90s for most locations to end the week. Southwesterly flow aloft becomes the dominant pattern moving into the weekend with embedded waves rippling through the flow. While the best upper level forcing will remain well off to the north, orographic forcing coupled with subtle waves will likely be enough to support at least a small chance of thunderstorms each day Thursday through the weekend. A thermal ridge will be in place across the region Thursday into Friday, with warm air aloft and subsequent capping concerns likely limiting more widespread storms. Additionally, bulk shear looks rather weak through Saturday (20 to 35 knots), further limiting overall severe potential. At this point, greatest likelihood for showers and storms looks to remain across south-central into eastern SD each day where higher quality boundary layer moisture will be in place. Westerly to southwesterly flow will continue through the weekend into next week with temperatures near normal and generally dry conditions expected. Dry westerly flow will likely result in elevated fire weather concerns beginning this weekend. At this point winds look to remain below criteria, however minimum daily RH values will likely fall into the teens, particularly across SW SD and NE WY this weekend into early next week. && .AVIATION...(For the 00Z TAFS Through 00Z Wednesday Evening) Issued At 453 PM MDT Tue Aug 4 2020 Isolated thunderstorms over northwest SD, as well as south central SD, will dissipate this evening. Brief MVFR/IFR conditions in stronger storms. Outside of storms, VFR conditions expected through the period. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && DISCUSSION...Eagan AVIATION...Johnson
Hazardous weather outlook, Aug 4, 12:43 PM CDT, 5 hours 56 minutes before
Hazardous Weather Outlook...UPDATED National Weather Service Rapid City SD 1143 AM MDT Tue Aug 4 2020 SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-051300- 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- 1143 AM MDT Tue Aug 4 2020 /1243 PM CDT Tue Aug 4 2020/ This Hazardous Weather Outlook is for all of western and south central South Dakota. .DAY ONE...This Afternoon and Tonight Isolated severe thunderstorms with large hail and strong wind gusts are possible this afternoon and early evening. .DAYS TWO THROUGH SEVEN...Wednesday through Monday Thunderstorms are possible through the weekend but widespread severe weather is not expected. .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 WYZ054>058-071-051300- Northern Campbell-Southern Campbell-Western Crook- Wyoming Black Hills-Weston-Northeastern Crook- 1143 AM MDT Tue Aug 4 2020 This Hazardous Weather Outlook is for northeastern Wyoming and the Black Hills of Wyoming. .DAY ONE...This Afternoon and Tonight Isolated thunderstorms are possible this afternoon but are not expect to become severe. .DAYS TWO THROUGH SEVEN...Wednesday through Monday Thunderstorms are possible through the weekend but widespread severe weather is not expected. .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
Local storm report, Aug 4, 6:30 PM CDT, 9 minutes before
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html>The office that day
Everything else NWS Rapid City, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 3, 8:23 PM CDT | Special Weather Statement | UNR | Lawrence | 37 min |
| Aug 3, 8:38 PM CDT | Special Weather Statement | UNR | Butte | 52 min |
| Aug 3, 9:12 PM CDT | Special Weather Statement | UNR | Butte | 48 min |
| Aug 4, 5:57 PM CDT | Severe Thunderstorm Warning | UNR | Tripp | 63 min |
| Aug 3, 7:34 PM CDT | Special Weather Statement | UNR | Crook | 41 min |
| Aug 3, 7:35 PM CDT | Special Weather Statement | UNR | Weston | 40 min |
| Aug 3, 8:18 PM CDT | Special Weather Statement | UNR | Crook | 42 min |
Nearby
Tornado Warnings in South Dakota, 2020Every tornado warning in 2020Tornadoes in 2020
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.