Alert archive / Iowa / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 50, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Jun 20, 1997, 10:30 PM CDT for Franklin County, Iowa. It was in force for 30 min. 2 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
- Jun 20, 1997, 10:30 PM CDT (03:30 UTC)
- Expired
- Jun 20, 1997, 11:00 PM CDT
- In force
- 30 min
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
County Franklin County, IA
The radar
The Des Moines radar (KDMX), 118 km from the middle of the area, began a volume at 03:33 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, 10:40 PM CDT | Thunderstorm Wind 50 | Alexander, IA | |
| Jun 20, 10:40 PM CDT | Hail 0.75 | Alexander, 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 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, 10:00 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Minneapolis, MN (KMPX), launched 00:00Z, 3.5 hours before the alert went out and 237 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
- 7 J/kg
- Mixed-layer CIN
- -198 J/kg
- Mixed-layer LCL
- 1504 m above ground
- 0-6 km bulk shear
- 74 kt
- 0-1 km storm-relative helicity
- -1 m²/s²
- 0-3 km storm-relative helicity
- 321 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.1
The text
As transmitted, in the capitals the NWS used until 2016.
619
WUUS1 KDSM 210329 RRA
SVRDSM
IAC069-210400-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1030 PM CDT FRI JUN 20 1997
* SEVERE THUNDERSTORM WARNING FOR
FRANKLIN COUNTY - NORTH CENTRAL IOWA
* UNTIL 1100 PM CDT
* SOME AREAS AFFECTED
ALEXANDER
CHAPIN
SHEFFIELD
* AT 1025 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM NEAR
ALEXANDER...40 MILES NORTHEAST OF FORT DODGE MOVING NORTHEAST AT 25
MPH.
* THE STORM WILL BE NEAR SHEFFIELD AT 1045 PM CDT.
THIS IS A DANGEROUS STORM. DO NOT GO OUTDOORS.
S2What 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
Local storm report, Jun 20, 6:03 PM CDT, 4 hours 27 minutes before
PRELIMINARY LOCAL STORM REPORT NATIONAL WEATHER SERVICE DES MOINES IA 603 PM CDT FRI JUN 20 1997 TIME(CDT) .....CITY LOCATION..... ST ...EVENT/REMARKS... DATE(CDT) ....COUNTY LOCATION.... 0449 PM INDIANOLA IA 0.85 INCH HAIL 06/20/97 WARREN
Local storm report, Jun 20, 6:05 PM CDT, 4 hours 25 minutes before
PRELIMINARY LOCAL STORM REPORT NATIONAL WEATHER SERVICE DES MOINES IA 603 PM CDT FRI JUN 20 1997 TIME(CDT) .....CITY LOCATION..... ST ...EVENT/REMARKS... DATE(CDT) ....COUNTY LOCATION.... 0449 nPM INDIANOLA IA 0.85 INCH HAIL 06/20/97 WARREN
Special weather statement, Jun 20, 9:35 PM CDT, 55 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-211200- CENTRAL IOWA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 935 PM CDT FRI JUN 20 1997 HAZARD -- NUMEROUS THUNDERSTORMS WITH ISOLATED SEVERE THUNDERSTORMS CAPABLE OF PRODUCING WIND GUSTS IN EXCESS OF 70 MPH...HAIL UP TO TWO INCHES IN DIAMETER...HEAVY RAIN AND ISOLATED TORNADOES. TIMING AND AREA OF CONCERN -- FROM 1100 PM UNTIL 300 AM OVER THE WEST PART OF THE FORECAST AREA AND SOUTH OF U.S. HIGHWAY 20...AFTER 100 AM EAST OF INTERSTATE 35...SOUTH OF U.S. HIGHWAY 20. THE THREAT WILL END OVER WESTERN IOWA BY 300 AM AND OVER THE EAST BY 600 AM. METEOROLOGICAL COMMENTS -- A BOUNDARY LEFT FROM CONVECTION LAST NIGHT EXTENDED FROM SOUTHERN NEBRASKA EAST THROUGH CENTRAL INTO EAST CENTRAL IOWA. IN ADDITION A COLD FRONT EXTENDED FROM THE NORTHEAST CORNER OF THE STATE...SOUTHWEST INTO THE WEST CENTRAL COUNTIES NEAR ONAWA. THE AIRMASS OVER IOWA IS VERY UNSTABLE WITH LIFTED INDICES IN THE -10 TO -15 DEGREE C RANGE. IN ADDITION...CAPE VALUES WERE ON THE ORDER OF 5000 TO 6000 J/KG. THE LATEST SURFACE ANALYSIS SHOWS DEW POINTS TEMPERATURES OF AT LEAST 75 DEGREES OVER THE SOUTHEAST HALF OF THE STATE. A FEW LOCATION WERE AROUND 80. IN ADDITION TO THE MOISTURE...THE LOW LEVEL JET WAS INCREASING THIS EVENING. SPEEDS WERE IN THE 35 TO 40 MPH RANGE BY MID EVENING. INTENSE THUNDERSTORMS WERE FORMING IN TWO AREAS THIS EVENING. ONE WAS OVER WESTERN NEBRASKA...THE SECOND OVER SOUTHEAST AND EAST CENTRAL NEBRASKA. THE TWO AREAS ARE LIKELY TO COMBINE AND ADVANCE EAST LATER TONIGHT. THE GREATEST THREAT OF SEVERE WEATHER WILL BE OVER THE WEST HALF OF IOWA...WITH THE THREAT OVER THE EAST BEING MORE FROM HEAVY RAIN. SPOTTY RAINFALL OF 3 TO 5 INCHES ARE POSSIBLE...ESPECIALLY SOUTH OF A SIOUX CITY TO OTTUMWA LINE. PRECAUTIONS -- EMERGENCY MANAGERS SHOULD REMAIN ALERT AS A WATCH IS LIKELY WITHIN THE NEXT HOUR. 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.
The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 20, 10:14 PM CDT | Severe Thunderstorm Warning | DMX | Wright | 31 min |
| Jun 20, 10:20 PM CDT | Severe Thunderstorm Warning | DMX | Webster | 35 min |
| Jun 20, 11:01 PM CDT | Severe Thunderstorm Warning | DMX | Franklin | 34 min |
| Jun 20, 11:33 PM CDT | Severe Thunderstorm Warning | DMX | Hardin | 32 min |
| Jun 20, 11:39 PM CDT | Severe Thunderstorm Warning | DMX | Butler, Grundy | 31 min |
| Jun 21, 12:04 AM CDT | Severe Thunderstorm Warning | DMX | Grundy, Hardin | 31 min |
| Jun 21, 12:21 AM CDT | Severe Thunderstorm Warning | DMX | Black Hawk, Grundy | 44 min |
| Jun 21, 12:28 AM CDT | Tornado Warning | DMX | Black Hawk | 32 min |
| Jun 21, 1:41 AM CDT | Severe Thunderstorm Warning | DMX | Audubon, Cass | 34 min |
| Jun 21, 2:39 AM CDT | Severe Thunderstorm Warning | DMX | Clarke, Warren | 31 min |
| Jun 21, 2:51 AM CDT | Severe Thunderstorm Warning | DMX | Polk, Warren | 34 min |
| Jun 21, 3:06 AM CDT | Severe Thunderstorm Warning | DMX | Lucas, Marion | 29 min |
| Jun 21, 3:21 AM CDT | Severe Thunderstorm Warning | DMX | Mahaska, Monroe | 34 min |
| Jun 21, 3:53 AM CDT | Severe Thunderstorm Warning | DMX | Wapello | 32 min |
| Jun 21, 4:27 PM CDT | Tornado Warning | DMX | Calhoun, Webster | 33 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.