Alert archive / South Dakota / Tornado Warnings in 1999
Tornado Warning 23, NWS Aberdeen, SD
NWS Aberdeen, SD issued this tornado warning at Aug 12, 1999, 12:27 AM MDT for Dewey County, South Dakota. It was in force for 33 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 12, 1999, 12:27 AM MDT (06:27 UTC)
- Expired
- Aug 12, 1999, 1:00 AM MDT
- In force
- 33 min
- Issued by
- NWS Aberdeen, SD
- Area
- Whole counties
County Dewey County, SD
The radar
The Bismarck radar (KBIS), 180 km from the middle of the area, began a volume at 06:28 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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Aug 11, 9:45 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Bismarck Municip, ND (KBIS), launched 00:00Z, 6.5 hours before the alert went out and 180 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
- 1951 J/kg
- Mixed-layer CIN
- -69 J/kg
- Mixed-layer LCL
- 806 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 126 m²/s²
- 0-3 km storm-relative helicity
- 265 m²/s²
- Significant tornado parameter
- 1.7
- Supercell composite
- 13.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KABR 120628 RRA TORABR SDC041-120700- BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE ABERDEEN SD 127 AM CDT THU AUG 12 1999 THE NATIONAL WEATHER SERVICE IN ABERDEEN HAS ISSUED A * TORNADO WARNING FOR... DEWEY COUNTY IN NORTH CENTRAL SOUTH DAKOTA * UNTIL 100 AM MDT (200 AM CDT) * AT 1226 AM MDT... ABERDEEN DOPPLER RADAR INDICATED A TORNADO 29 MILES SOUTHWEST OF MOBRIDGE OR 11 MILES SOUTHEAST OF TIMBER LAKE MOVING EAST AT 30 MPH. * THE TORNADO WILL BE NEAR... WHITEHORSE AT 1240 AM CDT IF YOU ARE IN A MULTIPLE STORY BUILDING...GO TO A SMALL INTERIOR ROOM AWAY FROM WINDOWS. JL/KH
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 Aberdeen, SD wrote its last area forecast discussion before this tornado warning went out at Aug 11, 8:00 PM MDT, 4 hours 27 minutes earlier.
Area forecast discussion, Aug 11, 8:00 PM MDT, 4 hours 27 minutes before
AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA NATIONAL WEATHER SERVICE ABERDEEN SD 9 PM CDT WED AUG 11 1999 CURRENT RADAR AND SATELITTE SHOWING VERY LITTLE CONVECTIVE ACTIVITY IN ABERDEEN COUNTY WARNING AREA. MSAS HAS LOW CENTER IN WEST CENTRAL SOUTH DAKOTA WITH WARM FRONT ALONG NORTH AND SOUTH DAKOTA BORDER. POTENTIAL IS STRONG ENOUGH TO STAY WITH CURRENT FORECAST AS LOW LEVEL JET STRENGTHENS. WILL UPDATE CURRENT PACKAGE FOR MINOR WORDING. .ABR...NONE. KEEFE
The office that day
Everything else NWS Aberdeen, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 11, 9:44 PM MDT | Severe Thunderstorm Warning | ABR | Corson | 61 min |
| Aug 11, 10:44 PM MDT | Severe Thunderstorm Warning | ABR | Corson | 61 min |
| Aug 11, 11:11 PM MDT | Severe Thunderstorm Warning | ABR | Dewey | 64 min |
| Aug 11, 11:44 PM MDT | Severe Thunderstorm Warning | ABR | Corson | 61 min |
| Aug 12, 12:11 AM MDT | Severe Thunderstorm Warning | ABR | Dewey | 64 min |
| Aug 12, 12:44 AM MDT | Severe Thunderstorm Warning | ABR | Corson | 61 min |
| Aug 12, 12:47 AM MDT | Severe Thunderstorm Warning | ABR | Walworth | 63 min |
| Aug 12, 1:05 AM MDT | Severe Thunderstorm Warning | ABR | Campbell | 65 min |
| Aug 12, 4:03 AM MDT | Severe Thunderstorm Warning | ABR | Brown, Spink | 47 min |
| Aug 12, 4:26 AM MDT | Tornado Warning | ABR | Brown, Spink | 49 min |
Nearby
Tornado Warnings in South Dakota, 1999Every tornado warning in 1999Tornadoes in 1999
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.