Alert archive / Iowa / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 10, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at May 7, 1997, 10:16 AM CDT for Palo Alto County, Pocahontas County, Iowa. It was in force for 44 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
- May 7, 1997, 10:16 AM CDT (15:16 UTC)
- Expired
- May 7, 1997, 11:00 AM CDT
- In force
- 44 min
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
Counties Palo Alto County, IA, Pocahontas County, IA
The radar
The Des Moines radar (KDMX), 153 km from the middle of the area, began a volume at 15:20 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 nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 3.3 hours before the alert went out and 225 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 963 m above ground
- 0-6 km bulk shear
- 46 kt
- 0-1 km storm-relative helicity
- 155 m²/s²
- 0-3 km storm-relative helicity
- 202 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 5.1
The text
As transmitted, in the capitals the NWS used until 2016.
000
TTAA00 KDSM 071516 RRA
SVRDSM
IAC147-151-071600-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1016 AM CDT WED MAY 7 1997
* SEVERE THUNDERSTORM WARNING FOR
SOUTHERN PALO ALTO COUNTY - NORTH CENTRAL IOWA
POCAHONTAS COUNTY - NORTHWESTERN IOWA
* UNTIL 1100 AM CDT
* SOME AREAS AFFECTED
LAURENS
HAVELOCK
POCAHONTAS
ALONG HIGHWAY 3
* AT 1013 AM CDT RADAR INDICATED A SEVERE THUNDERSTORM JUST ENTERING
WEST POCAHONTAS COUNTY...OR...30 MILES SOUTHEAST OF SPENCER MOVING
EAST AT 35 MPH.
* THE STORM WILL BE NEAR POCAHONTAS BY AROUND 1030 AM.
THIS IS A DANGEROUS STORM. DO NOT GO OUTDOORS.
A WIND GUST TO 70 MPH WAS REPORTED AT ALBERT CITY...30 MILES SOUTH OF
SPENCER.
FELDT
&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, May 7, 5:05 AM CDT, 5 hours 11 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-071700- CENTRAL IOWA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 505 AM CDT WED MAY 7 1997 HAZARD--SCATTERED BUT WEAK THUNDERSTORMS THIS MORNING. THUNDERSTORMS WILL THEN REDEVELOP AND FORM INTO A SQUALL LINE THIS AFTERNOON AND EVENING.. THE STRONGEST CELLS ON THE LINE MAY PRODUCE UP TO DIME SIZE HAIL AND WIND GUSTS UP TO 50 MPH. AREA OF CONCERN--THE ENTIRE DES MOINES COUNTY WARNING AREA. TIMING DETAILS--SCATTERED THUNDERSTORMS WILL AFFECT THE AREA THROUGH LATE MORNING...WITH REDEVELOPMENT EXPECTED AFTER 200 PM OVER WESTERN IOWA. THE LINE WILL THEN MOVE ACROSS THE STATE...EXITING THE WATERLOO AND OTTUMWA AREAS BY MID EVENING. METEOROLOGICAL COMMENTS--THUNDERSTORMS OVER IOWA THIS MORNING WERE IN ADVANCE OF A WARM FRONT EXTENDING FROM WESTERN NEBRASKA INTO NORTHERN MISSOURI. THE WARM FRONT WILL MOVE NORTH THIS MORNING AS A COLD FRONT OVER THE HIGH PLAINS BEGINS TO MOVE EAST. UPPER LEVEL SUPPORT AND INSTABILITY WILL REMAIN LACKING FOR THE STORMS THIS MORNING...KEEPING THE THREAT OF HAIL OR STRONG WINDS TO A MINIMUM. HOWEVER...CONDITIONS WILL CHANGE LATER TODAY AS WIND FIELDS THROUGHOUT THE ATMOSPHERE INCREASE ALONG AND AHEAD OF THE APPROACHING COLD FRONT. TEMPERATURES WILL ALSO COOL SLIGHTLY IN THE UPPER LEVELS AS SURFACE TEMPERATURES AND HUMIDITIES CLIMB. THE MAIN FORECAST QUESTION SURROUNDS THE AMOUNT OF SUN THE AREA MAY RECEIVE THIS AFTERNOON. IT APPEARS SKIES WILL REMAIN MOSTLY CLOUDY... KEEPING INSTABILITY SOMEWHAT MARGINAL. THERE IS A CHANCE...HOWEVER... THAT THE SUN WILL BREAK OUT FOR AN EXTENDED PERIOD OF TIME AHEAD OF THE COLD FRONT. IF THAT HAPPENS...THE ATMOSPHERE WOULD BECOME VERY UNSTABLE AND CAUSE THE EXPECTED SQUALL LINE TO STRENGTHEN. LARGE HAIL...DAMAGING WINDS...AND EVEN AN ISOLATED TORNADO OR TWO WOULD THEN BE POSSIBLE. PRECAUTIONS--SPOTTER ACTIVATION WILL NOT BE NEEDED THIS MORNING. HOWEVER...BECAUSE THE SITUATION THIS AFTERNOON AND EVENING IS NOT CERTAIN AS YET...FUTURE FORECASTS AND OUTLOOKS SHOULD BE MONITORED CLOSELY. THE NEXT OUTLOOK WILL BE ISSUED AROUND 1100 AM. PYTLAK
Special weather statement, May 7, 5:06 AM CDT, 5 hours 10 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-071700- CENTRAL IOWA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 505 AM CDT WED MAY 7 1997 HAZARD--SCATTERED BUT WEAK THUNDERSTORMS THIS MORNING. THUNDERSTORMS WILL THEN REDEVELOP AND FORM INTO A SQUALL LINE THIS AFTERNOON AND EVENING.. THE STRONGEST CELLS ON THE LINE MAY PRODUCE UP TO DIME SIZE HAIL AND WIND GUSTS UP TO 50 MPH. AREA OF CONCERN--THE ENTIRE DES MOINES COUNTY WARNING AREA. TIMING DETAILS--SCATTERED THUNDERSTORMS WILL AFFECT THE AREA THROUGH LATE MORNING...WITH REDEVELOPMENT EXPECTED AFTER 200 PM OVER WESTERN IOWA. THE LINE WILL THEN MOVE ACROSS THE STATE...EXITING THE WATERLOO AND OTTUMWA AREAS BY MID EVENING. METEOROLOGICAL COMMENTS--THUNDERSTORMS OVER IOWA THIS MORNING WERE IN ADVANCE OF A WARM FRONT EXTENDING FROM WESTERN NEBRASKA INTO NORTHERN MISSOURI. THE WARM FRONT WILL MOVE NORTH THIS MORNING AS A COLD FRONT OVER THE HIGH PLAINS BEGINS TO MOVE EAST. UPPER LEVEL SUPPORT AND INSTABILITY WILL REMAIN LACKING FOR THE STORMS THIS MORNING...KEEPING THE THREAT OF HAIL OR STRONG WINDS TO A MINIMUM. HOWEVER...CONDITIONS WILL CHANGE LATER TODAY AS WIND FIELDS THROUGHOUT THE ATMOSPHERE INCREASE ALONG AND AHEAD OF THE APPROACHING COLD FRONT. TEMPERATURES WILL ALSO COOL SLIGHTLY IN THE UPPER LEVELS AS SURFACE TEMPERATURES AND HUMIDITIES CLIMB. THE MAIN FORECAST QUESTION SURROUNDS THE AMOUNT OF SUN THE AREA MAY RECEIVE THIS AFTERNOON. IT APPEARS SKIES WILL REMAIN MOSTLY CLOUDY... KEEPING INSTABILITY SOMEWHAT MARGINAL. THERE IS A CHANCE...HOWEVER... THAT THE SUN WILL BREAK OUT FOR AN EXTENDED PERIOD OF TIME AHEAD OF THE COLD FRONT. IF THAT HAPPENS...THE ATMOSPHERE WOULD BECOME VERY UNSTABLE AND CAUSE THE EXPECTED SQUALL LINE TO STRENGTHEN. LARGE HAIL...DAMAGING WINDS...AND EVEN AN ISOLATED TORNADO OR TWO WOULD THEN BE POSSIBLE. PRECAUTIONS--SPOTTER ACTIVATION WILL NOT BE NEEDED THIS MORNING. HOWEVER...BECAUSE THE SITUATION THIS AFTERNOON AND EVENING IS NOT CERTAIN AS YET...FUTURE FORECASTS AND OUTLOOKS SHOULD BE MONITORED CLOSELY. THE NEXT OUTLOOK WILL BE ISSUED AROUND 1100 AM. PYTLAK
The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 7, 3:18 PM CDT | Severe Thunderstorm Warning | DMX | Crawford | 32 min |
| May 7, 3:48 PM CDT | Severe Thunderstorm Warning | DMX | Crawford | 17 min |
| May 7, 4:04 PM CDT | Severe Thunderstorm Warning | DMX | Carroll | 31 min |
| May 7, 4:29 PM CDT | Severe Thunderstorm Warning | DMX | Audubon | 31 min |
| May 7, 4:47 PM CDT | Severe Thunderstorm Warning | DMX | Adams | 33 min |
| May 7, 4:59 PM CDT | Severe Thunderstorm Warning | DMX | Audubon | 36 min |
| May 7, 5:41 PM CDT | Severe Thunderstorm Warning | DMX | Marion, Warren | 34 min |
| May 7, 5:52 PM CDT | Severe Thunderstorm Warning | DMX | Dallas, Guthrie | 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.