Alert archive / Iowa / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 251, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Jul 6, 1998, 6:53 PM CDT for Crawford County, Iowa. It was in force for 32 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
- Jul 6, 1998, 6:53 PM CDT (23:53 UTC)
- Expired
- Jul 6, 1998, 7:25 PM CDT
- In force
- 32 min
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
County Crawford County, IA
The radar
The Omaha radar (KOAX), 114 km from the middle of the area, began a volume at 23:55 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 |
|---|---|---|---|
| Jul 6, 5:15 PM CDT | Tornado Watch | SPC | 6 hr |
The nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 11.9 hours before the alert went out and 114 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
- 1215 J/kg
- Mixed-layer CIN
- -143 J/kg
- Mixed-layer LCL
- 979 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 5 m²/s²
- 0-3 km storm-relative helicity
- -19 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 062353 RRA SVRDSM IAC047-070025- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE DES MOINES IA 653 PM CDT MON JUL 6 1998 THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... CRAWFORD COUNTY IN WEST CENTRAL IOWA * UNTIL 725 PM CDT * AT 652 PM CDT... DOPPLER RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS 41 MILES SOUTHEAST OF SIOUX CITY OR 12 MILES WEST OF CHARTER OAK MOVING EAST SOUTHEAST AT 35 MPH. * THIS STORM CAN BE EXPECTED NEAR... RICKETTS BY 706 PM CDT CHARTER OAK BY 707 PM CDT SCHLESWIG BY 716 PM CDT DENISON BY 720 PM CDT DAMAGING WINDS IN EXCESS OF 60 MPH ARE LIKELY. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE WARNING. GO INSIDE A STURDY BUILDING AND STAY AWAY FROM WINDOWS! PYTLAK
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, Jul 6, 4:42 PM CDT, 2 hours 11 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-071100- CENTRAL IOWA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 442 PM CDT MON JUL 6 1998 HAZARD--WIDESPREAD HEAVY RAIN OF 1 TO 3 INCHES AND ISOLATED AMOUNTS UP TO 5. A FEW STORMS COULD ALSO PRODUCE WIND GUSTS TO 80 MPH AND HAIL UP TO GOLFBALL SIZE. AREA OF CONCERN--ALL OF CENTRAL IOWA. TIMING DETAILS--THE HEAVY RAIN THREAT WILL LAST ALL NIGHT AND INTO TUESDAY MORNING. THE SEVERE WEATHER THREAT WILL BE HIGHEST BETWEEN 800 PM AND 300 AM. METEOROLOGICAL COMMENTS--A THUNDERSTORM COMPLEX HAS ALREADY DEVELOPED OVER NORTHEAST NEBRASKA AND SOUTHEAST SOUTH DAKOTA THIS AFTERNOON WITH NUMEROUS SEVERE THUNDERSTORM WARNINGS IN EFFECT. WIND GUSTS UP TO 70 MPH AND 1 INCH DIAMETER HAIL HAVE ALREADY BEEN REPORTED. THIS COMPLEX WILL MOVE INTO IOWA AFTER DARK AS IT FEEDS ON EXTREMELY HIGH MOISTURE VALUES THROUGHOUT THE ATMOSPHERE. PRECIPITABLE WATERS WERE APPROACHING 2 INCHES THIS AFTERNOON WITH SURFACE DEWPOINTS APPROACHING 80 DEGREES. AS THE NIGHT WEARS ON THE THUNDERSTORMS SHOULD BECOME WEAKER...BUT THEY WILL ALSO BEGIN TO TRAIN ALONG AN EAST-WEST STATIONARY FRONT STUCK RIGHT OVER THE HEART OF IOWA. PRECAUTIONS--A FLASH FLOOD WATCH IS ALREADY IN EFFECT FOR THE ENTIRE STATE...AND SEVERE THUNDERSTORM WATCHES MAY BE REQUIRED LATER THIS EVENING. SPOTTER ACTIVATION IS A NEAR CERTAINTY TONIGHT...ESPECIALLY IN THE NORTHWEST HALF OF THE STATE WHERE THE STORMS WILL LIKELY BE AT THEIR STRONGEST LATE THIS EVENING. PYTLAK
Special weather statement, Jul 6, 4:58 PM CDT, 1 hour 55 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-071100- CENTRAL IOWA THUNDERSTORM OUTLOOK...UPDATED NATIONAL WEATHER SERVICE DES MOINES IA 458 PM CDT MON JUL 6 1998 HAZARD--WIDESPREAD HEAVY RAIN OF 1 TO 3 INCHES AND ISOLATED AMOUNTS UP TO 5. A FEW STORMS COULD ALSO PRODUCE WIND GUSTS TO 80 MPH AND HAIL UP TO GOLFBALL SIZE. AREA OF CONCERN--ALL OF CENTRAL IOWA. TIMING DETAILS--THE HEAVY RAIN THREAT WILL LAST ALL NIGHT AND INTO TUESDAY MORNING. THE SEVERE WEATHER THREAT WILL BE HIGHEST BETWEEN 800 PM AND 300 AM. METEOROLOGICAL COMMENTS--A THUNDERSTORM COMPLEX HAS ALREADY DEVELOPED OVER NORTHEAST NEBRASKA AND SOUTHEAST SOUTH DAKOTA THIS AFTERNOON WITH NUMEROUS SEVERE THUNDERSTORM WARNINGS IN EFFECT. WIND GUSTS UP TO 70 MPH AND 1 INCH DIAMETER HAIL HAVE ALREADY BEEN REPORTED. THIS COMPLEX WILL MOVE INTO IOWA AFTER DARK AS IT FEEDS ON EXTREMELY HIGH MOISTURE VALUES THROUGHOUT THE ATMOSPHERE. PRECIPITABLE WATERS WERE APPROACHING 2 INCHES THIS AFTERNOON WITH SURFACE DEWPOINTS APPROACHING 80 DEGREES. AS THE NIGHT WEARS ON THE THUNDERSTORMS SHOULD BECOME WEAKER...BUT THEY WILL ALSO BEGIN TO TRAIN ALONG AN EAST-WEST STATIONARY FRONT STUCK RIGHT OVER THE HEART OF IOWA. PRECAUTIONS--A FLASH FLOOD WATCH IS ALREADY IN EFFECT FOR THE ENTIRE STATE...AND A TORNADO WATCH WILL BE ISSUED FOR NORTHWEST IOWA SHORTLY. SPOTTER ACTIVATION IS A NEAR CERTAINTY TONIGHT...ESPECIALLY IN THE NORTHWEST HALF OF THE STATE WHERE THE STORMS WILL LIKELY BE AT THEIR STRONGEST LATE THIS EVENING. PYTLAK UPDATED TO MENTION IMPENDING TORNADO WATCH IN NORTHWEST IOWA
Nearby
Severe Thunderstorm Warnings in Iowa, 1998Every severe thunderstorm warning in 1998
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.