Alert archive / South Dakota / Tornado Warnings in 1999

Tornado Warning 21, NWS Aberdeen, SD

July 27, 1999Brown County, South Dakota

NWS Aberdeen, SD issued this tornado warning at Jul 27, 1999, 4:03 PM CDT for Brown County, South Dakota. It was in force for 32 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 27, 1999, 4:03 PM CDT (21:03 UTC)
Expired: Jul 27, 1999, 4:35 PM CDT
In force: 32 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 21:05 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 27, 4:15 PM CDT	Tornado F0	Hecla, SD	A tornado occurred 10 west of Hecla with no damage reported. Path length and width were estimated.

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 27, 2:30 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 9.1 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: 3 J/kg
Mixed-layer CIN: -442 J/kg
Mixed-layer LCL: 1364 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 121 m²/s²
0-3 km storm-relative helicity: 155 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KABR 272105
TORABR
SDC013-272135-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE ABERDEEN SD
403 PM CDT TUE JUL 27 1999

THE NATIONAL WEATHER SERVICE IN ABERDEEN HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHEASTERN BROWN COUNTY IN NORTHEASTERN SOUTH DAKOTA

* UNTIL 435 PM CDT

* AT 402 PM CDT... ABERDEEN DOPPLER RADAR INDICATED A TORNADO 32
  MILES NORTH OF ABERDEEN OR 9 MILES NORTHEAST OF FREDERICK MOVING
  SOUTHEAST AT 10 MPH.
6
* THE TORNADO WILL BE NEAR...
  HECLA      AT 425 PM

GO TO THE BASEMENT OR A SMALL INTERIOR ROOM ON THE LOWEST FLOOR!

AP/RE

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 27, 3:24 PM CDT	Severe Thunderstorm Warning	ABR	Edmunds	51 min
Jul 27, 3:44 PM CDT	Severe Thunderstorm Warning	ABR	Sully	36 min
Jul 27, 4:15 PM CDT	Severe Thunderstorm Warning	ABR	Hyde, Sully	50 min
Jul 27, 4:34 PM CDT	Severe Thunderstorm Warning	ABR	Brown	46 min
Jul 27, 4:48 PM CDT	Severe Thunderstorm Warning	ABR	Marshall	47 min
Jul 27, 4:51 PM CDT	Severe Thunderstorm Warning	ABR	Spink	64 min
Jul 27, 4:58 PM CDT	Severe Thunderstorm Warning	ABR	Faulk	47 min
Jul 27, 5:03 PM CDT	Severe Thunderstorm Warning	ABR	Hand, Hyde	62 min
Jul 27, 5:50 PM CDT	Severe Thunderstorm Warning	ABR	Roberts	50 min
Jul 27, 5:55 PM CDT	Severe Thunderstorm Warning	ABR	Spink	45 min
Jul 27, 6:15 PM CDT	Severe Thunderstorm Warning	ABR	Grant	50 min
Jul 27, 6:23 PM CDT	Severe Thunderstorm Warning	ABR	Clark	47 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.