Alert archive / Iowa / Flash Flood Warnings in 1993
Flash Flood Warning 112, NWS Des Moines, IA
NWS Des Moines, IA issued this flash flood warning at Aug 18, 1993, 4:25 PM CDT for Polk County, Iowa. It was in force for 4 hr.
The area
The counties it named.
The facts
- Issued
- Aug 18, 1993, 4:25 PM CDT (21:25 UTC)
- Expired
- Aug 18, 1993, 8:00 PM CDT
- In force
- 4 hr
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
County Polk County, IA
The nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 9.4 hours before the alert went out and 236 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
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KDSM 182124 FFWDSM IAC153-190100- BULLETIN - EBS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE DES MOINES IA 425 PM CDT WED AUG 18 1993 THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A FLASH FLOOD WARNING EFFECTIVE UNTIL 800 PM CDT FOR PEOPLE IN THE FOLLOWING LOCATION(S)... IN CENTRAL IOWA ...POLK COUNTY AT 420 PM CDT...A LINE OF SEVERE THUNDERSTORMS CONTINUED OVER POLK COUNTY...PRODUCING GUSTY WINDS...AND EXTREMELY HEAVY RAIN. THESE STORMS HAVE ALREADY PRODUCED 1 TO 1 1/2 INCHES OF RAIN ALONG AND NEAR WALNUT CREEK AND ADDITIONAL RAINFALL IS LIKELY...WITH SOME AREAS RECEIVING AROUND 2 INCHES OF RAIN. THIS EXTREME RAINFALL WILL CAUSE ADDITIONAL RISES ALONG AREA CREEKS AND STREAMS...INCLUDING WALNUT CREEK...BEAVER CREEK...JORDAN CREEK AND FOUR MILE CREEK. PEOPLE LIVING NEAR THESE CREEKS SHOULD PREPARE TO MOVE TO HIGHER GROUND IF FLOODING IS OBSERVED. A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS IMMINENT. MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS BRIDGES...DIPS...OR LOW SPOTS IF WATER COVERS THE ROADWAY. NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL ONE...ON FOOT. TO ESCAPE RISING WATER MOVE UP TO HIGHER GROUND. KALLMAN
What forecasters said that day
The local office's own words before this flash flood 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, 3:18 PM CDT, 1 hour 7 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, 1 hour 6 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, 39 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, 30 minutes 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
Special weather statement, Aug 18, 4:09 PM CDT, 16 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038- 039-040-182200- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE WATERLOO IA 410 PM CDT WED AUG 18 1993 ...SEVERE THUNDERSTORM WATCH FOR PORTIONS OF EAST CENTRAL IOWA... A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED ROUGHLY FOR AREAS ALONG AND SOUTH OF HIGHWAY 20 INCLUDING WATERLOO...GRUNDY CENTER...AND THE INDEPENDENCE AREA THROUGH 8 PM TONIGHT. AT 400 PM RADAR INDICATED INTENSE SHOWERS AND THUNDERSTORMS FROM CENTRAL INTO NORTH CENTRAL IOWA. THESE STORMS WERE MOVING EAST AT 35 MILES AN HOUR. ANOTHER SMALL AREA OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUED ALONG THE MISSISSIPPI RIVER TO THE SOUTH OF HIGHWAY 18. SHOWERS AND THUNDERSTORMS WITH BRIEF HEAVY RAIN...SMALL HAIL AND WIND GUST TO 40 MILES AN HOUR ARE GOING TO MOVE INTO THE MASON CITY...HAMPTON AND ST. ANSGAR AREAS THROUGH 5 PM AND WILL CONTINUE IN THE FOREST CITY AND GARNER AREAS THROUGH THE EARLY EVENINGZ HOURS. A FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE ENTIRE STATE. STAY TUNED TO NOAA WEATHER RADIO...LOCAL WEATHER RADIO AND TELEVISION FOR ADDITIONAL UPDATES AND POSSIBLE WARNINGS. TRS/PABST
Special weather statement, Aug 18, 4:09 PM CDT, 16 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038- 039-040-182200- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE WATERLOO IAED AUG 18 1993 ...SEVERE THUNDERSTORM WATCH FOR PORTIONS OF EAST CENTRAL IOWA... A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED ROUGHLY FOR AREAS ALONG AND SOUTH OF HIGHWAY 20 INCLUDING WATERLOO...GRUNDY CENTER...AND THE INDEPENDENCE AREA THROUGH 8 PM TONIGHT. AT INDICATED INTENSE SHOWERS AND THUNDERSTORMS FROM CENTRAL INTO NORTH CENTRAL IOWA. THESE STORMS WERE MOVING EAST AT 35 MILES AN HOUR. ANOTHER SMALL AREA OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUED ALONG THE MISSISSIPPI RIVER TO THE SOUTH OF HIGHWAY 18. SHOWERS AND T HEAVY RAIN...SMALL HAIL AND WIND GUST TO 40 MILES AN HOUR ARE GOING TO MOVE INTO THE MASON CITY...HAMPTON AND ST. ANSGAR AREAS THROUGH 5 PM AND WILL CONTINUE IN THE FOREST CITY AND GARNER AREAS THROUGH THE EARLY EVENING HOURS. A FLASH FLOOD WATCH REMAINS IN EFFECT FORTATE. STAY TUNED TO NOAA WEATHER RADIO...LOCAL WEATHER RADIO AND TELEVISION FOR ADDITIONAL UPDATES AND POSSIBLE WARNINGS. TRS/PABST
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, 3:56 PM CDT | Severe Thunderstorm Warning | DMX | Polk, Story | 64 min |
| 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
Flash Flood Warnings in Iowa, 1993Every flash flood 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.