Alert archive / South Dakota / Tornado Warnings in 1999

Tornado Warning 22, NWS Aberdeen, SD

July 30, 1999Hamlin County, South Dakota

NWS Aberdeen, SD issued this tornado warning at Jul 30, 1999, 1:55 PM CDT for Hamlin County, South Dakota. It was in force for 35 min. 4 reports 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 30, 1999, 1:55 PM CDT (18:55 UTC)
Expired
Jul 30, 1999, 2:30 PM CDT
In force
35 min
Issued by
NWS Aberdeen, SD
Area
Whole counties

County Hamlin County, SD

What was reported inside it

TimeReportWhereRemark
Jul 30, 2:10 PM CDTHail 2.75Hayti, SD
Jul 30, 2:10 PM CDTHail 0.75Bryant, SD
Jul 30, 2:15 PM CDTHail 2.75Thomas, SD
Jul 30, 2:26 PM CDTHail 1Castlewood, SD

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, 6.9 hours before the alert went out and 99 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-pSkew-T log-p diagram, Aberdeen, SD at 12:00Z on 1999-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 868 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 12:00Z on 1999-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -10 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
868 J/kg
Mixed-layer CIN
-237 J/kg
Mixed-layer LCL
2579 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
-10 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KABR 301856
TORABR
SDC057-301930-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE ABERDEEN SD
155 PM CDT FRI JUL 30 1999

THE NATIONAL WEATHER SERVICE IN ABERDEEN HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHERN HAMLIN COUNTY IN NORTHEASTERN SOUTH DAKOTA

* UNTIL 230 PM CDT

* AT 154 PM CDT... ABERDEEN DOPPLER RADAR INDICATED A TORNADO 13
  MILES SOUTH OF WATERTOWN OR 2 MILES SOUTH OF THOMAS  MOVING
  SOUTHEAST AT 10 MPH.

* THE VTORNADO WILL BE NEAR...
  THOMAS         AT 200 PM CDT
  HAYTI          AT 215 PM CDT

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

DH/RE

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 30, 10:37 AM CDT, 3 hours 18 minutes earlier.

Area forecast discussion, Jul 30, 10:37 AM CDT, 3 hours 18 minutes before
AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST
SOUTH DAKOTA AND WEST CENTRAL MINNESOTA
NATIONAL WEATHER SERVICE ABERDEEN SD
1030 AM CDT FRI JULY 30 1999

CONVECTION STARTING ALONG SURFACE FRONT.  LATEST 88D PICTURE SHOWS
FRONT MOVING THROUGH ABERDEEN.  ABERDEEN LOST 4 DEGREES AS FRONT
PUSHED THROUGH SO SHOULD END CONCERNS ABOUT HEAT ADVISORY.  WILL
UPDATE PACKAGE TO INCREASE CHANCE OF THUNDERSTORM AND LOWER EXPECTED
HIGHS.
v
.ABR...NONE.
KEEFE

In the hours before

Special weather statement, Jul 30, 10:55 AM CDT, 3 hours before
SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE  ABERDEEN SD
1055 AM CDT FRI JUL 30 1999

.A SURFACE LOW AND COLD FRONT IS MOVING THROUGH THE CENTRAL AND WEST
PARTS OF THE AREA.  CONVECTION IS STARTING ALONG THE FRONT.  THESE
STORMS ARE NOT EXPECTED TO BECOME SEVERE IN THE WEST AND CENTRAL BUT
THERE IS A SLIGHT CHANCE OF STORMS BECOMING SEVERE IN THE EAST PART
OF THE ABERDEEN WARNING AREA.

SDZ007-008-011-020-021-023-MNZ039-046-311600-
BIG STONE MN-CODINGTON-DAY-DEUEL-GRANT-MARSHALL-ROBERTS-TRAVERSE MN-
INCLUDING THE CITIES OF BRITTON...CLEAR LAKE...MILBANK...ORTONVILLE...
SISSETON...WATERTOWN...WEBSTER...WHEATON

THUNDERSTORMS WILL LIKELY MOVE THROUGH THE AREA THIS AFTERNOON.
THERE IS A SLIGHT CHANCE THESE STORMS MAY BECOME SEVERE.  SPOTTER
ACTIVATION MAY BE REQUIRED LATE THIS AFTERNOON.

SDZ003>006-009-010-015>019-022-033>037-045-048-051-311600-
BROWN-BUFFALO-CAMPBELL-CLARK-CORSON-DEWEY-EDMUNDS-FAULK-HAMLIN-HAND-
HUGHES-HYDE-JONES-LYMAN-MCPHERSON-POTTER-SPINK-STANLEY-SULLY-
WALWORTH-
INCLUDING THE CITIES OF ABERDEEN...CASTLEWOOD...CLARK...EUREKA...
FAULKTON...FT PIERRE...FT THOMPSON...GETTYSBURG...HIGHMORE...
MCINTOSH...MILLER...MOBRIDGE...MOUND CITY...MURDO...ONIDA...PIERRE...
PRESHO...REDFIELD...ROSCOE...TIMBER LAKE

THUNDERSTORMS ARE OCCURING.  THEY ARE NOT EXPECTED TO BECOME SEVERE.
SPOTTER ACTIVATION IS NOT ANTICIPATED.

KEEFE

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 7:11 PM CDTSevere Thunderstorm WarningABRStanley29 min
Jul 29, 7:16 PM CDTFlash Flood WarningABRStanley3 hr
Jul 29, 7:39 PM CDTSevere Thunderstorm WarningABRLyman46 min
Jul 30, 1:35 PM CDTSevere Thunderstorm WarningABRCodington50 min
Jul 30, 1:47 PM CDTSevere Thunderstorm WarningABRHamlin63 min
Jul 30, 1:58 PM CDTSevere Thunderstorm WarningABRClark47 min
Jul 30, 2:08 PM CDTSevere Thunderstorm WarningABRDeuel47 min
Jul 30, 2:18 PM CDTSevere Thunderstorm WarningABRHamlin47 min
Jul 30, 2:23 PM CDTSevere Thunderstorm WarningABRCodington62 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.