Alert archive / Iowa / Severe Thunderstorm Warnings in 1993
Severe Thunderstorm Warning 228, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Aug 18, 1993, 3:56 PM CDT for Polk County, Story County, Iowa. It was in force for 64 min.
The area
The counties it named.
The facts
- Issued
- Aug 18, 1993, 3:56 PM CDT (20:56 UTC)
- Expired
- Aug 18, 1993, 5:00 PM CDT
- In force
- 64 min
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
Counties Polk County, IA, Story County, IA
The nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 8.9 hours before the alert went out and 245 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
- 1510 J/kg
- Mixed-layer CIN
- -153 J/kg
- Mixed-layer LCL
- 1800 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 35 m²/s²
- 0-3 km storm-relative helicity
- 20 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.
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, Aug 18, 2:55 PM CDT, 1 hour 1 minute before
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</html>Special weather statement, Aug 18, 3:01 PM CDT, 55 minutes before
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</html>Special weather statement, Aug 18, 3:18 PM CDT, 38 minutes before
IAC153-182115- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DES MOINES IA 319 PM CDT WED AUG 18 1993 ...THUNDERSTORMS ARE DEVELOPING AROUND DES MOINES...BUT SEVERE STORMS ARE MORE LIKELY AFTER 4 PM... AT 315 PM...SCATTERED THUNDERSTORMS HAD POPPED UP ACROSS PARTS OF THE DES MOINES METRO AREA...MAINLY ACROSS EAST SECTIONS. FURTHER TO THE WEST...ABOUT 35 MILES WEST OF DES MOINES...A LINE OF SEVERE THUNDERSTORMS WAS PRODUCING HEAVY RAIN...HAIL AND DAMAGING WINDS. IT IS LIKELY THAT THESE STORMS WILL HOLD TOGETHER AND REACH THE DES MOINES METRO AREA BETWEEN 415 AND 445 PM THIS AFTERNOON. IF YOU PLAN ANY OUTDOOR ACTIVITIES DURING THIS TIME...YOU SHOULD KEEP AN EYE ON THE SKY...KEEP INFORMED TO THE LATEST WEATHER INFORMATION...AND KEEP WITHIN A SHORT DISTANCE OF A SAFE SHELTER. FELDT
Special weather statement, Aug 18, 3:19 PM CDT, 37 minutes before
IAC153-182115- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DES MOINES IA 319 PM CDT WED AUG 18 1993 ...THUNDERSTORMS ARE DEVELOPING AROUND DES MOINES...BUT SEVERE STORMS ARE MORE LIKELY AFTER 4 PM... AT 315 PM...SCATTERED THUNDERSTORMS HAD POPPED UP ACROSS PARTS OF THE DES MOINES METRO AREA...MAINLY ACROSS EAST SECTIONS. FURTHER TO THE WEST...ABOUT 35 MILES WEST OF DES MOINES...A LINE OF SEVERE THUNDERSTORMS WAS PRODUCING HEAVY RAIN...HAIL AND DAMAGING WINDS. IT IS LIKELY THAT THESE STORMS WILL HOLD TOGETHER AND REACH THE DES MOINES METRO AREA BETWEEN 415 AND 445 PM THIS AFTERNOON. IF YOU PLAN ANY OUTDOOR ACTIVITIES DURING THIS TIME...YOU SHOULD KEEP AN EYE ON THE SKY...KEEP INFORMED TO THE LATEST WEATHER INFORMATION...AND KEEP WITHIN A SHORT DISTANCE OF A SAFE SHELTER. FELDT
Special weather statement, Aug 18, 3:46 PM CDT, 10 minutes before
IAC153-182145- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DES MOINES IA 345 PM CDT WED AUG 18 1993 ...SEVERE THUNDERSTORMS ARE LIKELY IN DES MOINES... AT 340 PM...A LINE OF SEVERE THUNDERSTORMS WAS LOCATED 20 MILES WEST OF DES MOINES. THIS AREA OF THUNDERSTORMS WILL PUSH ACROSS THE DES MOINES METRO AREA BETWEEN 415 AND 5 PM. AS THE STORMS PASS...WINDS WILL BE STRONG AND GUSTY...THERE IS A CHANCE FOR HAIL...AND THERE WILL BE VERY HEAVY RAIN. RAINFALL AMOUNTS FROM THESE STORMS COULD REACH AROUND TWO INCHES. MOTORISTS SHOULD DRIVE WITH CAUTION AS THE STORMS MOVE NEAR. IF YOU HAVE OUTDOOR ACTIVITIES PLANNED DURING THIS TIME...YOU MIGHT WANT TO POSTPONE THEM...OR REMAIN NEAR A SHELTER. ...SPECIAL MENTION FOR FAIRGROUND WORKERS...THESE STRONG STORMS ARE LIKELY TO AFFECT THE FAIRGROUNDS. FELDT
Special weather statement, Aug 18, 3:55 PM CDT, 1 minute before
IAZALL-181945- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 355 PM CDT WED AUG 18 1993 ...A FLASH FLOOD WATCH IS IN EFFECT FOR ALL OF IOWA THIS AFTERNOON AND EVENING... ...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR CENTRAL AND SOUTHERN IOWA UNTIL 8 PM... AT 331 PM CDT...AN AREA OF SHOWERS AND INTENSE THUNDERSTORMS D OVER MUCH OF WEST CENTRAL INTO NORTHWEST IOWA. THE SHOWERS AND STORMS WERE GENERALLY WEST OF A LINE FROM 45 MILES WEST OF LAMONI...NEAR BEDFORD TO 20 MILES WEST OF DES MOINES...NEAR DALLAS CENTER TO NEAR MASON CITY. THE STRONGEST STORMS WERE IN A 20 MILE WIDE BAG FROM 45 MILES SOUTHWEST OF DES MOINES...NEAR GREENFIELD TO NEAR FORT DODGE. THESE STORMS WILL PRODUCE TORRENTIAL RAINS...INTENSE THUNDERSTORM WINDS...HAIL AND FREQUENT DEADLY LIGHTNING. ANOTHER AREA OF SHOWERS AND ISOLATED STRONG THUNDERSTORMS WAS OVER PORTIONS OF CENTRAL AND SOUTHEAST IOWA...GENERALLY ALONG AND 20 ILES EITHER SIDE OF A LINE FROM DES MOINES TO BURLINGTON. THE SHOWERS AND STORMS WERE MOVING EAST AT NEARLY 40 MILES AN HOUR. PETERSEN
The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 5:30 AM CDT | Flash Flood Warning | DMX | Iowa | 3 hr |
| Aug 18, 12:53 PM CDT | Severe Thunderstorm Warning | DMX | Johnson, Linn | 22 min |
| Aug 18, 1:21 PM CDT | Severe Thunderstorm Warning | DMX | Crawford | 54 min |
| Aug 18, 2:07 PM CDT | Severe Thunderstorm Warning | DMX | Audubon, Carroll | 53 min |
| Aug 18, 2:14 PM CDT | Severe Thunderstorm Warning | DMX | Sac | 46 min |
| Aug 18, 2:29 PM CDT | Severe Thunderstorm Warning | DMX | Calhoun, Greene | 46 min |
| Aug 18, 2:54 PM CDT | Severe Thunderstorm Warning | DMX | Greene, Guthrie | 51 min |
| Aug 18, 3:11 PM CDT | Severe Thunderstorm Warning | DMX | Adair | 34 min |
| Aug 18, 3:13 PM CDT | Severe Thunderstorm Warning | DMX | Webster | 47 min |
| Aug 18, 3:29 PM CDT | Severe Thunderstorm Warning | DMX | Boone, Dallas, Madison | 46 min |
| Aug 18, 3:38 PM CDT | Flash Flood Warning | DMX | Greene | 3 hr |
| Aug 18, 3:38 PM CDT | Flash Flood Warning | DMX | Greene | 3 hr |
| Aug 18, 4:25 PM CDT | Flash Flood Warning | DMX | Polk | 4 hr |
| Aug 18, 4:25 PM CDT | Severe Thunderstorm Warning | DMX | Warren | 50 min |
| Aug 18, 5:07 PM CDT | Severe Thunderstorm Warning | DMX | Keokuk, Mahaska | 38 min |
| Aug 18, 5:17 PM CDT | Severe Thunderstorm Warning | DMX | Marion | 43 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 1993Every severe thunderstorm warning in 1993
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.