Alert archive / Iowa / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 28, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this severe thunderstorm warning at Jun 20, 1997, 6:29 AM CDT for Sioux County, Iowa. It was in force for 36 min. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Jun 20, 1997, 6:29 AM CDT (11:29 UTC)
- Expired
- Jun 20, 1997, 7:05 AM CDT
- In force
- 36 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Whole counties
County Sioux County, IA
The radar
The Sioux Falls radar (KFSD), 72 km from the middle of the area, began a volume at 11:28 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.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jun 20, 4:15 AM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 20, 5:00 AM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 11.5 hours before the alert went out and 197 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.
- Mixed-layer CAPE
- 1320 J/kg
- Mixed-layer CIN
- -2 J/kg
- Mixed-layer LCL
- 2762 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 37 m²/s²
- 0-3 km storm-relative helicity
- 58 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.4
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KFSD 201129 RRA SVRFSD IAC167-201205- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE SIOUX FALLS SD 629 AM CDT FRI JUN 20 1997 * SEVERE THUNDERSTORM WARNING FOR EASTERN SIOUX COUNTY - IN NORTHWESTERN IOWA * UNTIL 705 AM CDT * SOME AREAS AFFECTED NEWKIRK AROUND 645 AM CDT GRANVILLE AROUND 650 AM CDT HOSPERS AROUND 650 AM CDT * AT 628 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 26 MILES SOUTHWEST OF SIBLEY OR 10 MILES NORTHWEST OF NEWKIRK MOVING EAST AT 35 MPH. WHEN THUNDERSTORMS ARE OCCURRING...PEOPLE SHOULD MOVE INSIDE A STRONG BUILDING. DO NOT STAND BY WINDOWS. DO NOT USE TELEPHONES OR ELECTRICAL APPLIANCES UNTIL THE STORM HAS PASSED UNLESS IN AN EMERGENCY. MOTORISTS SHOULD NOT DRIVE INTO LOW WATER CROSSINGS. HEITKAMP
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.
NWS Sioux Falls, SD wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 19, 8:29 PM CDT, 10 hours earlier.
Area forecast discussion, Jun 19, 8:29 PM CDT, 10 hours before
SOUTH DAKOTA/NORTHWEST IOWA/SOUTHWEST MINNESOTA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SIOUX FALLS SD 830 PM CDT WED JUN 18 1997 SEVERE THUNDERSTORM POTENTIAL HAS NOT DEVELOPED AS WELL AS EARLIER EXPECTED AND SOME ADJUSTMENT TO EARLIER CWA ZONES WILL BE MADE. WILL ADJUST ZONES IN LINE WITH SPC CHANGES TO WATCH AREA WHICH IS ANTICIPATED AROUND 9 PM. WILL LOWER THE POPS FOR LATER TONIGHT FOLLOWING THE THUNDERSTORMS MOVING ALONG THE SOUTHEAST BORDER. POTENTIAL FOR SEVERE THUNDERSTORMS YET THROUGH MIDNIGHT FROM AROUND YANKTON ON EAST INTO NORTHWEST IOWA AS THE THUNDERSTORMS MOVE INTO THAT AREA. .FSD...NONE UMLAND
In the hours before
Special weather statement, Jun 20, 1:45 AM CDT, 4 hours 44 minutes before
IAZ001>003-012>014-020>022-031-032-MNZ089-090-098-200800- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 145 AM CDT FRI JUN 20 1997 ...SEVERE THUNDERSTORM WATCH HAS BEEN ALLOWED TO EXPIRE... SEVERE THUNDERSTORM WATCH NUMBER 482 FOR PARTS OF SOUTHWEST MINNESOTA AND NORTHWEST IOWA HAS BEEN ALLOWED TO EXPIRE. SCATTERED THUNDERSTORMS WILL MOVE ACROSS EAST ACROSS THE AREA THE REST OF TONIGHT...BUT THE STORMS ARE NOT EXPECTED TO BECOME SEVERE. HOWEVER A FEW OF THE STORMS WILL BE STRONG ENOUGH TO PRODUCE HEAVY RAIN...SMALL HAIL...AND GUSTY WINDS. RUBY
Special weather statement, Jun 20, 1:45 AM CDT, 4 hours 44 minutes before
IAZ001>003-012>014-020>022-031-032-MNZ089-090-098-200800- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 145 AM CDT FRI JUN 20 1997 ...CORRECTED FOR EXTRA WORDING IN LINE 3... ...SEVERE THUNDERSTORM WATCH HAS BEEN ALLOWED TO EXPIRE... SEVERE THUNDERSTORM WATCH NUMBER 482 FOR PARTS OF SOUTHWEST MINNESOTA AND NORTHWEST IOWA HAS BEEN ALLOWED TO EXPIRE. SCATTERED THUNDERSTORMS WILL MOVE EAST ACROSS THE AREA FOR THE REST OF TONIGHT...BUT THE STORMS ARE NOT EXPECTED TO BECOME SEVERE. HOWEVER A FEW OF THE STORMS WILL BE STRONG ENOUGH TO PRODUCE HEAVY RAIN...SMALL HAIL...AND GUSTY WINDS. RUBY
Special weather statement, Jun 20, 1:51 AM CDT, 4 hours 38 minutes before
IAZ001>003-012>014-020>022-031-032-MNZ089-090-098-200800- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 145 AM CDT FRI JUN 20 1997 ...CORRECTED FOR EXTRA WORDING IN LINE 3... ...SEVERE THUNDERSTORM WATCH HAS BEEN ALLOWED TO EXPIRE... SEVERE THUNDERSTORM WATCH NUMBER 482 FOR PARTS OF SOUTHWEST MINNESOTA AND NORTHWEST IOWA HAS BEEN ALLOWED TO EXPIRE. SCATTERED THUNDERSTORMS WILL MOVE EAST ACROSS THE AREA FOR THE REST OF ,TONIGHT...BUT THE STORMS ARE NOT EXPECTED TO BECOME SEVERE. HOWEVER A FEW OF THE STORMS WILL BE STRONG ENOUGH TO PRODUCE HEAVY RAIN...SMALL HAIL...AND GUSTY WINDS. RUBY
The office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 20, 2:51 AM CDT | Severe Thunderstorm Warning | FSD | Plymouth | 29 min |
| Jun 20, 3:34 AM CDT | Severe Thunderstorm Warning | FSD | Buena Vista, Cherokee | 31 min |
| Jun 20, 5:54 AM CDT | Severe Thunderstorm Warning | FSD | Lyon, Sioux | 31 min |
| Jun 20, 8:28 AM CDT | Severe Thunderstorm Warning | FSD | O'Brien, Osceola | 32 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 1997Every severe thunderstorm warning in 1997
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; radar from the NEXRAD Level II archive.