Alert archive / South Dakota / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 64, NWS Aberdeen, SD

July 20, 1987Brown County, South Dakota

NWS Aberdeen, SD issued this severe thunderstorm warning at Jul 20, 1987, 2:31 AM CDT for Brown County, South Dakota. It was in force for 59 min.

The area

The counties it named.

The facts

Issued
Jul 20, 1987, 2:31 AM CDT (07:31 UTC)
Expired
Jul 20, 1987, 3:30 AM CDT
In force
59 min
Issued by
NWS Aberdeen, SD
Area
Whole counties

County Brown County, SD

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Aberdeen, SD (KHON), launched 00:00Z, 7.5 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-pSkew-T log-p diagram, Aberdeen, SD at 00:00Z on 1987-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2687 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 00:00Z on 1987-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 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
2687 J/kg
Mixed-layer CIN
-41 J/kg
Mixed-layer LCL
1437 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
155 m²/s²
Significant tornado parameter
0.4
Supercell composite
3.5

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 severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Jul 19, 10:35 PM CDT, 3 hours 56 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ABERDEEN SD
934 PM CDT SUN JUL 19 1987

AT 930 PM CDT RADAR INDICATED AN INTENSE THUNDERSTORM 35 MILES SOUTHEAST
OF ABERDEEN...NEAR CONDE IN NORTHEAST SOUTH DAKOTA. THIS IS A NEW STORM
THAT HAS DEVELOPED RAPIDLY. MOVEMENT WAS NORTH AT 5 MPH.

PERSONS IN THE PATH OF THIS STORM SHOULD STAY ALERT FOR POSSIBLE SEVERE
WEATHER DEVELOPMENT AND TAKE SHELTER IF NECESSARY.
HUSTON
Special weather statement, Jul 19, 11:46 PM CDT, 2 hours 45 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ABERDEEN SD
1145 PM CDT SUN JUL 19 1987

AT 1140 PM CDT RADAR INDICATED AN INTENSE THUNDERSTORM 25 MILES NORTHEAST
OF ABERDEEN...NEAR CLAREMONT IN NORTHEAST SOUTH DAKOTA. THIS IS STORM
ALSO EXTENDS INTO WESTERN MARSHALL COUNTY. MOVEMENT WAS NORTH AT 10 MPH.

PERSONS IN THE PATH OF THIS STORM SHOULD STAY ALERT FOR POSSIBLE SEVERE
WEATHER DEVELOPMENT AND TAKE SHELTER IF NECESSARY.
HUSTON

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 19, 9:33 PM CDTTornado WarningABRCorson27 min
Jul 19, 10:54 PM CDTTornado WarningABRCorson36 min
Jul 19, 11:01 PM CDTSevere Thunderstorm WarningABRBrown, Day, Spink59 min
Jul 19, 11:13 PM CDTTornado WarningABRCorson32 min
Jul 19, 11:58 PM CDTTornado WarningABRCorson32 min
Jul 20, 12:28 AM CDTSevere Thunderstorm WarningABRBrown62 min
Jul 20, 12:37 AM CDTTornado WarningABRCorson38 min
Jul 20, 12:52 AM CDTSevere Thunderstorm WarningABRSpink38 min
Jul 20, 1:08 AM CDTSevere Thunderstorm WarningABRCampbell67 min
Jul 20, 1:21 AM CDTSevere Thunderstorm WarningABRJones34 min
Jul 20, 1:21 AM CDTSevere Thunderstorm WarningABRHughes, Lyman, Stanley69 min
Jul 20, 1:35 AM CDTSevere Thunderstorm WarningABRBrown, McPherson55 min
Jul 20, 3:03 AM CDTSevere Thunderstorm WarningABRDay, Marshall57 min
Jul 20, 7:52 AM CDTSevere Thunderstorm WarningABRMarshall, Roberts48 min
Jul 20, 5:14 PM CDTSevere Thunderstorm WarningABRClark61 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 1987Every severe thunderstorm warning in 1987

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.