Alert archive / South Dakota / Tornado Warnings in 1999

Tornado Warning 14, NWS Aberdeen, SD

July 8, 1999Brown County, South Dakota

NWS Aberdeen, SD issued this tornado warning at Jul 8, 1999, 12:22 AM CDT for Brown County, South Dakota. It was in force for 48 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Jul 8, 1999, 12:22 AM CDT (05:22 UTC)
Expired: Jul 8, 1999, 1:10 AM CDT
In force: 48 min
Issued by: NWS Aberdeen, SD
Area: Whole counties

County Brown County, SD

The radar

The Aberdeen radar (KABR), 16 km from the middle of the area, began a volume at 05:25 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 was reported inside it

Time	Report	Where	Remark
Jul 8, 12:30 AM CDT	Thunderstorm Wind 61	Aberdeen, SD	Winds gusting to 70 mph brought down some large tree branches along with some power lines west of Aberdeen.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 7, 11:30 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 5.4 hours before the alert went out and 77 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 22 J/kg
Mixed-layer CIN: -361 J/kg
Mixed-layer LCL: 2040 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: -4 m²/s²
0-3 km storm-relative helicity: 137 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

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 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 Jul 7, 9:01 PM CDT, 3 hours 21 minutes earlier.

Area forecast discussion, Jul 7, 9:01 PM CDT, 3 hours 21 minutes before

AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST
SOUTH DAKOTA AND WEST CENTRAL MINNESOTA
NATIONAL WEATHER SERVICE ABERDEEN SD
900 PM CDT WED JULY 7 1999

CURRENTLY WATCHING CONVECTION IN WESTERN SOUTH DAKOTA.  CURRENT CAPE
VALUES OF OVER 4K J/KG WITH -8 LIS IN PIR AREA PER LAPS MODEL.  00Z
ABR SOUNDING SHOWS WARM MID LEVEL WITH H7 TEMP OF +11 C.  CURRENT
GOES SOUNDINGS ALSO SHOW WARM MID LEVELS WITH SIMILAR H7 TEMPS.  ETA
SHOWS STRONG WAA ESPECIALLY AT MID LEVEL WHICH SHOULD INHBIT
CONVECTION TRYING TO MOVE INTO OUR CWA.  CURRENT PACKAGE DESCRIBES
SITUATION WELL AND NO CHANGES ARE ANTICIPATED.

.ABR...NONE.
KEEFE

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 7, 10:08 PM CDT	Severe Thunderstorm Warning	ABR	Corson	32 min
Jul 7, 10:19 PM CDT	Severe Thunderstorm Warning	ABR	Campbell	36 min
Jul 7, 11:19 PM CDT	Severe Thunderstorm Warning	ABR	Campbell, McPherson	31 min
Jul 7, 11:50 PM CDT	Tornado Warning	ABR	McPherson	35 min
Jul 8, 12:20 AM CDT	Tornado Warning	ABR	Edmunds	30 min
Jul 8, 12:24 AM CDT	Tornado Warning	ABR	McPherson	36 min
Jul 8, 1:28 AM CDT	Flash Flood Warning	ABR	McPherson	4 hr
Jul 8, 1:46 AM CDT	Severe Thunderstorm Warning	ABR	Brown	64 min
Jul 8, 2:43 AM CDT	Severe Thunderstorm Warning	ABR	Day	62 min

Nearby

Tornado Warnings in South Dakota, 1999 Every tornado warning in 1999 Tornadoes 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.