Alert archive / South Dakota / Tornado Warnings in 1999

Tornado Warning 16, NWS Aberdeen, SD

July 22, 1999Potter County, Sully County, South Dakota

NWS Aberdeen, SD issued this tornado warning at Jul 22, 1999, 5:29 PM CDT for Potter County, Sully County, South Dakota. It was in force for 36 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 22, 1999, 5:29 PM CDT (22:29 UTC)
Expired: Jul 22, 1999, 6:05 PM CDT
In force: 36 min
Issued by: NWS Aberdeen, SD
Area: Whole counties

Counties Potter County, SD, Sully County, SD

What was reported inside it

Time	Report	Where	Remark
Jul 22, 5:30 PM CDT	Tornado F0	Onida, SD	A tornado touched down briefly on a farm southeast of Onida. Over half of the roof of a 40 by 45 foot building was torn off and deposited in a tree belt 200 yards to the north. The south wall of this building was caved in and the north wall was pulled out and

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 nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 10.5 hours before the alert went out and 130 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: 1958 J/kg
Mixed-layer CIN: -260 J/kg
Mixed-layer LCL: 1086 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 104 m²/s²
0-3 km storm-relative helicity: 140 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KABR 222230
TORABR
SDC107-222305-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE ABERDEEN SD
529 PM CDT THU JUL 22 1999

THE NATIONAL WEATHER SERVICE IN ABERDEEN HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHERN POTTER COUNTY IN NORTH CENTRAL SOUTH DAKOTA

* UNTIL 605 PM CDT

* AT 528 PM CDT... ABERDEEN DOPPLER RADAR AND SPOTTER REPORTS
  INDICATED A TORNADO 22 MILES NORTHEAST OF PIERRE MOVING NORTHEAST
  AT 10 MPH.

* THE TORNADfO WILL BE NEAR...

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

&

DH/GS

1 follow-up statement

000 
TTAA00 KABR 222237 RRC
TORABR
SDC119-222305-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING...CORRECTION FOR SULLY COUNTY
NATIONAL WEATHER SERVICE ABERDEEN SD
529 PM CDT THU JUL 22 1999

THE NATIONAL WEATHER SERVICE IN ABERDEEN HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHERN SULLY COUNTY IN NORTH CENTRAL SOUTH DAKOTA

* UNTIL 605 PM CDT

* AT 528 PM CDT... ABERDEEN DOPPLER RADAR AND SPOTTER REPORTS
  INDICATED A TORNADO 22 MILES NORTHEAST OF PIERRE MOVING NORTHEAST
  AT 10 MPH.


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

DH/GS

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 22, 3:19 PM CDT, 2 hours 10 minutes earlier.

Area forecast discussion, Jul 22, 3:19 PM CDT, 2 hours 10 minutes before

AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST
SOUTH DAKOTA AND WEST CENTRAL MINNESOTA
NATIONAL WEATHER SERVICE ABERDEEN SD
315 PM CDT THU JULY 22 1999

TSRAS ALREADY BREAKING THROUGH THE CAP ALONG SFC TROUGH EXTENDING
ACROSS C AND NC SD LATE THIS AFTERNOON. SATELLITE DERIVED PRODUCTS
SHOWED A VERY UNSTABLE AIRMASS ACROSS MOST OF THE ABR CWA WITH LIS DOWN
TO -12 AND CAPES OF 4-6 THOUSAND. HIGH DWPTS IN THE MID TO UPPER 70S
AND TEMPS IN THE 90S TO OVER 100 WERE WEAKENING THE CAP. SATELLITE
PRODUCTS CINH SHOWED THE CAP WEAKENING THE FASTEST IN C SD WHERE TSRAS
ARE PRESENTLY DEVELOPING. ALSO...A GOOD THETA-E RIDGE IS IN PLACE OVER
NE SD AND WC MN. THEREFORE...AS TROUGH MOVES THROUGH TONIGHT...THERE
WILL BE A CHANCE OF TSRAS OVER ALL OF THE AREA. FRIDAY SHOULD AGAIN BE
A HOT DAY WITH LESS HUMIDITY AS DWPTS FALL INTO THE 60S. FOR FRIDAY
NIGHT AND SATURDAY...MDLS SHOW UPPER RIDGE HOLDING IN STRONG WITH UPPER
DISTURBANCES ROLING OVER IT. DUE TO THE TIMING AND STRENGTH OF THESE
WAVES...WILL LEAVE OUT POPS FOR THE CWA FOR FRIDAY NIGHT AND SATURDAY.
FOR SUNDAY THROUGH TUESDAY...THE WEATHER PATTERN CHANGES VERY
LITTLE...EXCEPT FOR ON MONDAY ACROSS NE SD AND WC MN WHERE THE AVN SHOWS
A S/W MOVING OVER THE AREA...SO WILL PUT IN A CHANCE OF TSRAS HERE. DID
NOT STRAY MUCH FROM GUIDANCE TEMPS.

.ABR...NONE.

MOHR

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 22, 3:59 PM CDT	Severe Thunderstorm Warning	ABR	Lyman	46 min
Jul 22, 4:59 PM CDT	Severe Thunderstorm Warning	ABR	Hughes, Stanley	46 min
Jul 22, 5:17 PM CDT	Severe Thunderstorm Warning	ABR	Sully	48 min
Jul 22, 6:01 PM CDT	Flash Flood Warning	ABR	Sully	2 hr
Jul 22, 6:18 PM CDT	Tornado Warning	ABR	McPherson	32 min
Jul 22, 6:38 PM CDT	Tornado Warning	ABR	McPherson	32 min
Jul 22, 6:50 PM CDT	Tornado Warning	ABR	Edmunds	35 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.