Alert archive / Iowa / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 12, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this severe thunderstorm warning at Jun 20, 1997, 2:51 AM CDT for Plymouth County, Iowa. It was in force for 29 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
- Jun 20, 1997, 2:51 AM CDT (07:51 UTC)
- Expired
- Jun 20, 1997, 3:20 AM CDT
- In force
- 29 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Whole counties
County Plymouth County, IA
The radar
The Sioux Falls radar (KFSD), 103 km from the middle of the area, began a volume at 07:52 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 |
|---|---|---|---|
| Jun 20, 3:05 AM CDT | Thunderstorm Wind 62 | Le Mars, IA |
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
Omaha, NE (KOAX), launched 00:00Z, 7.9 hours before the alert went out and 158 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.
629 WUUS1 KFSD 200751 RRA SVRFSD IAC149-200820- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE SIOUX FALLS SD 251 AM CDT FRI JUN 20 1997 * SEVERE THUNDERSTORM WARNING FOR PLYMOUTH COUNTY - IN NORTHWESTERN IOWA * UNTIL 320 AM CDT * SOME AREAS AFFECTED LE MARS AROUND 255 AM CDT MERRILL AROUND 255 AM CDT SENEY AROUND 255 AM CDT OYENS AROUND 300 AM CDT REMSEN AROUND 310 AM CDT * AT 247 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 19 MILES NORTH OF SIOUX CITY OR 4 MILES SOUTHWEST OF LE MARS MOVING EAST AT 30 MPH. SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55 MPH... DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS.
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, 6 hours 22 minutes earlier.
Area forecast discussion, Jun 19, 8:29 PM CDT, 6 hours 22 minutes 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
Local storm report, Jun 19, 10:55 PM CDT, 3 hours 56 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1055 PM CDT THU JUN 19 1997
TIME(CDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0910 PM CLAYTON SD 1.25 INCH HAIL
06/19/97 HUTCHINSON 4 MILES SOUTH OF CLAYTON
UMLANDSpecial weather statement, Jun 19, 11:04 PM CDT, 3 hours 47 minutes before
NEZ013-014-SDZ060>062-065>071-200510- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 1104 PM CDT THU JUN 19 1997 THE SEVERE THUNDERSTORM WATCH NUMBER 482 WHICH WAS IN EFFECT FOR EXTREME SOUTHEAST SOUTH DAKOTA AND DAKOTA AND DIXON COUNTIES OF EXTREME NORTHEAST NEBRASKA HAS BEEN CANCELED. THUNDERSTORMS HAVE MOVED OUT OF THE AREA. ADDITIONAL THUNDERSTORMS MAY DEVELOP LATER TONIGHT. UMLAND
Special weather statement, Jun 20, 1:45 AM CDT, 1 hour 6 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, 1 hour 6 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, 1 hour 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, 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, 6:29 AM CDT | Severe Thunderstorm Warning | FSD | Sioux | 36 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.