Alert archive / Iowa / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 47, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Jun 20, 1997, 4:39 PM CDT for Warren County, Iowa. It was in force for 31 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, 4:39 PM CDT (21:39 UTC)
- Expired
- Jun 20, 1997, 5:10 PM CDT
- In force
- 31 min
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
County Warren County, IA
The radar
The Des Moines radar (KDMX), 46 km from the middle of the area, began a volume at 21:38 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, 4:49 PM CDT | Hail 0.85 | Indianola, 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 12:00Z, 9.7 hours before the alert went out and 235 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
- 381 J/kg
- Mixed-layer CIN
- -172 J/kg
- Mixed-layer LCL
- 3033 m above ground
- 0-6 km bulk shear
- 46 kt
- 0-1 km storm-relative helicity
- 129 m²/s²
- 0-3 km storm-relative helicity
- 287 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
TTAA00 KDSM 202138 RRA
SVRDSM
IAC181-202210-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
439 PM CDT FRI JUN 20 1997
* SEVERE THUNDERSTORM WARNING FOR
CENTRAL AND NORTHERN WARREN COUNTY - SOUTH CENTRAL IOWA
* UNTIL 510 PM CDT
* SOME AREAS AFFECTED
INDIANOLA
ACKWORTH
CARLISLE
* AT 435 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM 5 MILES SOUTH OF
INDIANOLA OR 20 MILES SOUTH OF DES MOINES MOVING EAST AT 10 MPH.
* THE STORM WILL BE NEAR INDIANOLA AT 445 PM CDT.
THIS IS A DANGEROUS STORM. LARGE HAIL IS LIKELY WITH THIS STORM. DO
NOT GO OUTDOORS.
SCHAFERWhat 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, Jun 20, 11:12 AM CDT, 5 hours 27 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-202015- CENTRAL IOWA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 1113 AM CDT FRI JUN 20 1997 HAZARD--SCATTERED SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 70 MPH...ISOLATED TORNADOES...HAIL TO 1 INCH IN DIAMETER AND HEAVY RAINFALL. TIMING AND AREA OF CONCERN--NORTHERN IOWA INTO EARLY THIS AFTERNOON. 200 PM TO 600 PM OVER THE REMAINDER OF THE STATE. METEOROLOGICAL COMMENTS--SEVERAL OUTFLOW BOUNDARIES HAVE FORMED FROM THE EARLY MORNING THUNDERSTORM ACTIVITY ACROSS NORTHERN AND WESTERN IOWA. THE ONGOING CONVECTION ACROSS NORTHERN IOWA IS FORECAST TO SLOWLY MOVE OUT OF THE STATE BY MID AFTERNOON WHILE SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE OUTFLOW BOUNDARIES IN CENTRAL AND SOUTHERN IOWA. CLOUDINESS FROM THE THUNDERSTORM COMPLEX ACROSS NORTHERN IOWA SHOULD BEGIN TO THIN EARLY THIS AFTERNOON ALLOWING SUNSHINE TO WARM TEMPERATURES WELL INTO THE 80S. SURFACE DEW POINTS WILL BE IN THE LOWER 70S RESULTING IN A VERY UNSTABLE AIR MASS. CAPES ARE FORECAST TO BE AROUND 4000 J/KG WITH PRECIPITABLE WATER VALUES NEAR 1.75 INCHES. ANOTHER IN A SERIES OF FAST MOVING UPPER LEVEL DISTURBANCES IS EXPECTED TO TRACK ACROSS THE NORTHERN PLAINS THIS AFTERNOON AND INTO THE GREAT LAKES TONIGHT. LOW LEVEL CONVERGENCE AND UPPER LEVEL DIVERGENCE WILL INCREASE OVER IOWA AHEAD OF THIS FEATURE THIS AFTERNOON AND EVENING INCREASING THE THREAT FOR THUNDERSTORMS. WIND PROFILES ARE FORECAST TO BE MORE UNIDIRECTIONAL LATER TODAY AND TONIGHT SUGGESTING THE GREATEST THREAT WITH THE THUNDERSTORMS WOULD BE WITH STRAIGHT LINE WIND DAMAGE. HOWEVER...THE SHEAR PROFILE NEAR THE OUTFLOW BOUNDARIES MAY BE ENOUGH TO SUPPORT ISOLATED SUPERCELLS AND TORNADOES. LATE THIS MORNING THE OUTFLOW BOUNDARIES WERE LOCATED FROM SOUTHWEST THROUGH NORTHEAST IOWA...WITH A WEAKER BOUNDARY LOCATED OVER CENTRAL IOWA JUST SOUTH OF DES MOINES. IN ADDITION...ABUNDANT LOW LEVEL MOISTURE WAS PRESENT ACROSS THE STATE AS SURFACE DEW POINTS WERE IN THE MIDDLE 70S ACROSS CENTRAL IOWA. THE THUNDERSTORMS THIS AFTERNOON SHOULD CONSOLIDATE INTO ANOTHER CONVECTIVE COMPLEX TONIGHT BRINGING THE ADDITIONAL THREAT OF EXCESSIVE RAINFALL TO THE SOUTH HALF OF THE STATE. RAINFALL OF FROM 1 TO 3 INCHES IS POSSIBLE BY FRIDAY MORNING WITH ISOLATED AREAS RECEIVING NEARLY 5 INCHES. PRECAUTIONS--SPOTTER ACTIVATION IS LIKELY FOR THIS AFTERNOON AND EVENING. KEEP ABREAST OF THE LATEST SHORT TERM FORECASTS AND CENTRAL IOWA THUNDERSTORM OUTLOOKS THIS AFTERNOON. PERSONS LIVING IN OR NEAR AREAS THAT ARE FLOOD PRONE SHOULD BE ESPECIALLY ALERT OF THE THUNDERSTORMS LATER THIS AFTERNOON AND TONIGHT AS EXCESSIVE RAINFALL IS A DISTINCT POSSIBILITY WITH A FEW OF THE STORMS. SMITH
Special weather statement, Jun 20, 11:13 AM CDT, 5 hours 26 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-202015- CENTRAL IOWA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 1113 AM CDT FRI JUN 20 1997 HAZARD--SCATTERED SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 70 MPH...ISOLATED TORNADOES...HAIL TO 1 INCH IN DIAMETER AND HEAVY RAINFALL. TIMING AND AREA OF CONCERN--NORTHERN IOWA INTO EARLY THIS AFTERNOON. 200 PM TO 600 PM OVER THE REMAINDER OF THE STATE. METEOROLOGICAL COMMENTS--SEVERAL OUTFLOW BOUNDARIES HAVE FORMED FROM THE EARLY MORNING THUNDERSTORM ACTIVITY ACROSS NORTHERN AND WESTERN IOWA. THE ONGOING CONVECTION ACROSS NORTHERN IOWA IS FORECAST TO SLOWLY MOVE OUT OF THE STATE BY MID AFTERNOON WHILE SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE OUTFLOW BOUNDARIES IN CENTRAL AND SOUTHERN IOWA. CLOUDINESS FROM THE THUNDERSTORM COMPLEX ACROSS NORTHERN IOWA SHOULD BEGIN TO THIN EARLY THIS AFTERNOON ALLOWING SUNSHINE TO WARM TEMPERATURES WELL INTO THE 80S. SURFACE DEW POINTS WILL BE IN THE LOWER 70S RESULTING IN A VERY UNSTABLE AIR MASS. CAPES ARE FORECAST TO BE AROUND 4000 J/KG WITH PRECIPITABLE WATER VALUES NEAR 1.75 INCHES. ANOTHER IN A SERIES OF FAST MOVING UPPER LEVEL DISTURBANCES IS EXPECTED TO TRACK ACROSS THE NORTHERN PLAINS THIS AFTERNOON AND INTO THE GREAT LAKES TONIGHT. LOW LEVEL CONVERGENCE AND UPPER LEVEL DIVERGENCE WILL INCREASE OVER IOWA AHEAD OF THIS FEATURE THIS AFTERNOON AND EVENING INCREASING THE THREAT FOR THUNDERSTORMS. WIND PROFILES ARE FORECAST TO BE MORE UNIDIRECTIONAL LATER TODAY AND TONIGHT SUGGESTING THE GREATEST THREAT WITH THE THUNDERSTORMS WOULD BE WITH STRAIGHT LINE WIND DAMAGE. HOWEVER...THE SHEAR PROFILE NEAR THE OUTFLOW BOUNDARIES MAY BE ENOUGH TO SUPPORT ISOLATED SUPERCELLS AND TORNADOES. LATE THIS MORNING THE OUTFLOW BOUNDARIES WERE LOCATED FROM SOUTHWEST THROUGH NORTHEAST IOWA...WITH A WEAKER BOUNDARY LOCATED OVER CENTRAL IOWA JUST SOUTH OF DES MOINES. IN ADDITION...ABUNDANT LOW LEVEL MOISTURE WAS PRESENT ACROSS THE STATE AS SURFACE DEW POINTS WERE IN THE MIDDLE 70S ACROSS CENTRAL IOWA. THE THUNDERSTORMS THIS AFTERNOON SHOULD CONSOLIDATE INTO ANOTHER CONVECTIVE COMPLEX TONIGHT BRINGING THE ADDITIONAL THREAT OF EXCESSIVE RAINFALL TO THE SOUTH HALF OF THE STATE. RAINFALL OF FROM 1 TO 3 INCHES IS POSSIBLE BY FRIDAY MORNING WITH ISOLATED AREAS RECEIVING NEARLY 5 INCHES. PRECAUTIONS--SPOTTER ACTIVATION IS LIKELY FOR THIS AFTERNOON AND EVENING. KEEP ABREAST OF THE LATEST SHORT TERM FORECASTS AND CENTRAL IOWA THUNDERSTORM OUTLOOKS THIS AFTERNOON. PERSONS LIVING IN OR NEAR AREAS THAT ARE FLOOD PRONE SHOULD BE ESPECIALLY ALERT OF THE THUNDERSTORMS LATER THIS AFTERNOON AND TONIGHT AS EXCESSIVE RAINFALL IS A DISTINCT POSSIBILITY WITH A FEW OF THE STORMS. SMITH
Special weather statement, Jun 20, 2:55 PM CDT, 1 hour 44 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-210000- CENTRAL IOWA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 256 PM CDT FRI JUN 20 1997 HAZARD -- SCATTERED SEVERE THUNDERSTORMS...CAPABLE OF PRODUCING WIND GUSTS IN EXCESS OF 70 MPH...HAIL UP TO ONE INCH IN DIAMETER...HEAVY RAIN AND ISOLATED TORNADOES. TIMING AND AREA OF CONCERN -- ISOLATED DEVELOPMENT LATE THIS AFTERNOON AND EVENING WITH WIDESPREAD THUNDERSTORMS EXPECTED ACROSS THE STATE TONIGHT. METEOROLOGICAL COMMENTS -- THE BOUNDARY LEFT OVER FROM THIS MORNINGS CONVECTION WAS LOCATED FROM SOUTHWEST IOWA THROUGH EAST CENTRAL IOWA. MESO ANALYSIS INDICATED A THERMAL RIDGE OVER EXTREME WESTERN WITH A MOISTURE AXIS IN CENTRAL IOWA. THE BEST AREA FOR DEVELOPMENT AT THIS TIME WILL BE IN THE VICINITY OF THE OLD OUTFLOW BOUNDARY BETWEEN THE THERMAL AND MOISTURE AXES. THE 19Z SURFACE ANALYSIS AND RADAR BOTH INDICATED NUMEROUS BOUNDARIES ACROSS THE STATE. ABUNDANT MOISTURE WAS ALSO AVAILABLE WITH DEW POINTS OVER 75 DEGREES ACROSS CENTRAL AND SOUTHERN IOWA...PLACING THE HEAVIEST RAINFALL OVER SOUTHERN IOWA. RAINFALL AMOUNTS WILL AVERAGE FROM ONE TO TWO INCHES OVER THE SOUTHERN HALF OF IOWA...WITH LOCAL AMOUNTS REACHING UP TO FIVE INCHES BY SATURDAY MORNING. ISOLATED THUNDERSTORMS ARE FORECAST TO DEVELOP LATE THIS AFTERNOON ALONG THE OLD OUTFLOW BOUNDARY OVER SOUTHERN IOWA WHERE THE ATMOSPHERE IS EXTREMELY UNSTABLE. THE LOW LEVEL JET WILL INTENSIFY LATE THIS AFTERNOON AND TONIGHT REINFORCING THE CONVERGENCE ALONG THE OUTFLOW BOUNDARY. THE LOW LEVEL WIND PROFILE ALONG THE OUTFLOW BOUNDARY MAY BE SUFFICIENT ENOUGH TO SUPPORT ISOLATED SUPERCELLS. OVERNIGHT...THUNDERSTORMS ARE EXPECTED TO BECOME MORE NUMEROUS ACROSS THE STATE. THE PRIMARY THREAT LATE TONIGHT INTO SATURDAY MORNING WILL BE EXCESSIVE RAINFALL. PRECAUTIONS -- EMERGENCY MANAGERS SHOULD REMAIN ALERT. SPOTTER ACTIVATION MAY BE NEEDED THIS EVENING. STAY TUNED TO LOCAL TV...CABLE TV OR NOAA WEATHER RADIO FOR THE LATEST SHORT-TERM FORECAST AND SEVERE WEATHER OUTLOOK. SCHAFER/SMITH
Special weather statement, Jun 20, 2:56 PM CDT, 1 hour 43 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-210000- CENTRAL IOWA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 256 PM CDT FRI JUN 20 1997 HAZARD -- SCATTERED SEVERE THUNDERSTORMS...CAPABLE OF PRODUCING WIND GUSTS IN EXCESS OF 70 MPH...HAIL UP TO ONE INCH IN DIAMETER...HEAVY RAIN AND ISOLATED TORNADOES. TIMING AND AREA OF CONCERN -- ISOLATED DEVELOPMENT LATE THIS AFTERNOON AND EVENING WITH WIDESPREAD THUNDERSTORMS EXPECTED ACROSS THE STATE TONIGHT. METEOROLOGICAL COMMENTS -- THE BOUNDARY LEFT OVER FROM THIS MORNINGS CONVECTION WAS LOCATED FROM SOUTHWEST IOWA THROUGH EAST CENTRAL IOWA. MESO ANALYSIS INDICATED A THERMAL RIDGE OVER EXTREME WESTERN WITH A MOISTURE AXIS IN CENTRAL IOWA. THE BEST AREA FOR DEVELOPMENT AT THIS TIME WILL BE IN THE VICINITY OF THE OLD OUTFLOW BOUNDARY BETWEEN THE THERMAL AND MOISTURE AXES. THE 19Z SURFACE ANALYSIS AND RADAR BOTH INDICATED NUMEROUS BOUNDARIES ACROSS THE STATE. ABUNDANT MOISTURE WAS ALSO AVAILABLE WITH DEW POINTS OVER 75 DEGREES ACROSS CENTRAL AND SOUTHERN IOWA...PLACING THE HEAVIEST RAINFALL OVER SOUTHERN IOWA. RAINFALL AMOUNTS WILL AVERAGE FROM ONE TO TWO INCHES OVER THE SOUTHERN HALF OF IOWA...WITH LOCAL AMOUNTS REACHING UP TO FIVE INCHES BY SATURDAY MORNING. ISOLATED THUNDERSTORMS ARE FORECAST TO DEVELOP LATE THIS AFTERNOON ALONG THE OLD OUTFLOW BOUNDARY OVER SOUTHERN IOWA WHERE THE ATMOSPHERE IS EXTREMELY UNSTABLE. THE LOW LEVEL JET WILL INTENSIFY LATE THIS AFTERNOON AND TONIGHT REINFORCING THE CONVERGENCE ALONG THE OUTFLOW BOUNDARY. THE LOW LEVEL WIND PROFILE ALONG THE OUTFLOW BOUNDARY MAY BE SUFFICIENT ENOUGH TO SUPPORT ISOLATED SUPERCELLS. OVERNIGHT...THUNDERSTORMS ARE EXPECTED TO BECOME MORE NUMEROUS ACROSS THE STATE. THE PRIMARY THREAT LATE TONIGHT INTO SATURDAY MORNING WILL BE EXCESSIVE RAINFALL. PRECAUTIONS -- EMERGENCY MANAGERS SHOULD REMAIN ALERT. SPOTTER ACTIVATION MAY BE NEEDED THIS EVENING. STAY TUNED TO LOCAL TV...CABLE TV OR NOAA WEATHER RADIO FOR THE LATEST SHORT-TERM FORECAST AND SEVERE WEATHER OUTLOOK. SCHAFER/SMITH
The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 20, 12:48 AM CDT | Severe Thunderstorm Warning | DMX | Cass | 32 min |
| Jun 20, 1:20 AM CDT | Severe Thunderstorm Warning | DMX | Adair, Cass | 50 min |
| Jun 20, 5:02 AM CDT | Severe Thunderstorm Warning | DMX | Webster | 33 min |
| Jun 20, 5:17 AM CDT | Severe Thunderstorm Warning | DMX | Hamilton, Wright | 33 min |
| Jun 20, 5:48 AM CDT | Severe Thunderstorm Warning | DMX | Franklin, Hardin | 32 min |
| Jun 20, 6:09 AM CDT | Severe Thunderstorm Warning | DMX | Butler, Grundy | 36 min |
| Jun 20, 6:45 AM CDT | Severe Thunderstorm Warning | DMX | Black Hawk | 45 min |
| Jun 20, 7:25 AM CDT | Severe Thunderstorm Warning | DMX | Butler | 35 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.