Alert archive / South Dakota / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 142, NWS Aberdeen, SD
NWS Aberdeen, SD issued this severe thunderstorm warning at Aug 12, 1999, 12:11 AM MDT for Dewey County, South Dakota. It was in force for 64 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, 12:11 AM MDT (06:11 UTC)
- Expired
- Aug 12, 1999, 1:15 AM MDT
- In force
- 64 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 06:12 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, 6.2 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
The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.
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 Aberdeen, SD wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 11, 8:00 PM MDT, 4 hours 11 minutes earlier.
Area forecast discussion, Aug 11, 8:00 PM MDT, 4 hours 11 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, 12:27 AM MDT | Tornado Warning | ABR | Dewey | 33 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
Severe Thunderstorm Warnings in South Dakota, 1999Every severe thunderstorm warning 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.