Alert archive / Iowa / Flash Flood Warnings in 1993
Flash Flood Warning 71, NWS Des Moines, IA
NWS Des Moines, IA issued this flash flood warning at Jul 17, 1993, 5:44 AM CDT for Story County, Iowa. It was in force for 3 hr.
The area
The counties it named.
The facts
- Issued
- Jul 17, 1993, 5:44 AM CDT (10:44 UTC)
- Expired
- Jul 17, 1993, 8:45 AM CDT
- In force
- 3 hr
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
County Story County, IA
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 10.7 hours before the alert went out and 254 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
- 646 J/kg
- Mixed-layer CIN
- -84 J/kg
- Mixed-layer LCL
- 987 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 80 m²/s²
- 0-3 km storm-relative helicity
- 231 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KDSM 171045 FFWDSM IAC169-171345- BULLETIN - EBS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE DES MOINES IA 544 AM CDT SAT JUL 17 1993 THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A FLASH FLOOD WARNING EFFECTIVE UNTIL 900 AM CDT FOR PEOPLE IN THE FOLLOWING LOCATION(S)... IN CENTRAL IOWA ...STORY COUNTY AT 530 AM CDT SQUAW CREEK WAS OVER THE FLOOD STAGE OF SEVEN FEET. MORE THAN 2.5 INCHES OF RAIN HAS FALLEN IN THE COUNTY...AND DUE TO THE HIGHLY SATURATED GROUND CONDITIONS ALL RAINFALL WILL RUNOFF RAPIDLY. THOUGH THE RIGHT BANK OF THE CREEK WILL NOT OVERFLOW UNTIL 11 FEET IS REACHED THE RAPID NATURE OF THE CREEK TO FLOOD WILL ALLOW LITTLE TIME BETWEEN STAGES. HEAVY RAINS CONTINUED IN THE COUNTY AND IN THE SQUAW CREEK BASIN. BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE DANGERS OF FLOODS AND FLASH FLOODS. IF FLASH FLOODING IS OBSERVED...ACT QUICKLY. MOVE UP TO ESCAPE FLOOD@ WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.
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, Jul 17, 4:23 AM CDT, 1 hour 21 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038- 039-040-141025- SPECIAL WEATHER STATEMENT...CORRECTION FOR WORDING NATIONAL WEATHER SERVICE WATERLOO IA 415 AM CDT SAT JUL 17 1993 ...THUNDERSTORMS ARE MOVING INTO NORTHEAST IOWA... AT 415 AM RADAR INDICATED STRONG THUNDERSTORM CELLS OVER WATERLOO. ANOTHER STRONG CELL WAS IN THE RURAL AREA 10 MILES NORTHWEST OF WATERLOO AND ANOTHER STORM WAS 10 MILES NORTH OF WATERLOO NEAR WAVERLY. THE STORMS WERE MOVING TO THE NORTHEAST AT 15 TO 20 MILES AN HOUR. SHOWERS AND THUNDERSTORMS COVER AN AREA FROM WATERLOO... NORTHWEST TO MASON CITY TO CHARLES CITY...35 MILES NORTH OF WATERLOO. ANOTHER AREA OF SHOWERS AND THUNDERSTORMS WILL AGAIN AFFECT AREAS TO THE WEST OF HIGHWAY 218 BETWEEN 430 AND 530 AM. SHOWERS AND THUNDERSTORMS WILL MOVE INTO THE INDEPENDENCE...WEST UNION AND FAYETTE AREAS BETWEEN 430 AND 530 AM AND WILL PRODUCE BRIEF HEAVY RAIN...GUSTY WINDS AND DEADLY LIGHTNINxG. DP
Special weather statement, Jul 17, 4:23 AM CDT, 1 hour 21 minutes before
IAZ047-048-171100- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DES MOINES IA 415 AM CDT SAT JUL 17 1993 ...CONCERNING HEAVY RAINS OVER STORY AND BOONE COUNTIES... SINCE MIDNIGHT SEVERAL LINES OF THUNDERSTORMS HAVE MOVED OVER MUCH OF STORY AND BOONE COUNTIES IN CENTRAL IOWA. CHECKING WITH LAW ENFORCEMENT OFFICIALS IN THOSE COUNTIES THERE WERE NO KNOWN PROBLEMS WITH ROADS...RIVERS...OR CREEKS. HOWEVER WITH THE SATURATED GROUND CONDITIONS IN THE STATE...WATER FROM HEAVY RAINFALL COULD POOL OR FILL A SMALL CREEK QUITE RAPIDLY. THEREFORE REMEMBER RULE ONE OF FLOOD SAFETY - DO NOT ATTEMPT TO WALK OR DRIVE THROUGH MOVING OR STANDING WATER OF UNKNOWN DEPTH...ESPECIALLY AT NIGHT. CALLS TO RIVER GAGES IN THE AREA DO NOT INDICATE ANY RAPID RISES OR OVERFLOW AT THIS TIME. PEOPLE IN THOSE COUNTIES SHOULD REMAIN ALERT AND TAKE NECESSARY ACTION IF NEEDED. FORSTER
Special weather statement, Jul 17, 4:43 AM CDT, 1 hour 1 minute before
IAZALL-171040- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 443 AM CDT SAT JUL 17 1993 AT 430 AM CDT...WIDELY SCATTERED STRONG THUNDERSTORMS AND SCATTERED SHOWERS CONTINUED OVER A LARGE PART OF IOWA. A 70 MILE WIDE AREA OF WIDELY SCATTERED STRONG STORMS CONTINUED OVER THE NORTH HALF OF IOWA...CENTERED FROM 20 MILES SOUTHWEST OF FORT DODGE TO NEAR WATERLOO. OTHER STRONG STORMS WERE LOCATED 35 TO 45 MILES NORTHEAST OF SIOUX CITY NEAR PRIMGHAR...AND ALSO 30 MILES NORTHEAST OF OTTUMWA NEAR KEOTA. SOME OF THESE STORMS WERE PRODUCING VERY HEAVY RAIN...FREQUENT LIGHTNING AND POSSIBLY SOME SMALL HAIL. THE STORMS AND SHOWERS OVER THE NORTH HALF OF IOWA WERE MOVING NORTHEAST AT 20 MILES AN HOUR. OVER SOUTHEAST IOWA THE STORMS AND SHOWERS WERE MOVING EAST AT AROUND 10 MILES AN HOUR. KALLMAN
Special weather statement, Jul 17, 4:44 AM CDT, 1 hour before
IAZALL-171040- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 443 AM CDT SAT JUL 17 1993 AT 430 AM CDT...WIDELY SCATTERED STRONG THUNDERSTORMS AND SCATTERED SHOWERS CONTINUED OVER A LARGE PART OF IOWA. A 70 MILE WIDE AREA OF WIDELY SCATTERED STRONG STORMS CONTINUED OVER THE NORTH HALF OF IOWA...CENTERED FROM 20 MILES SOUTHWEST OF FORT DODGE TO NEAR WATERLOO. OTHER STRONG STORMS WERE LOCATED 35 TO 45 MILES NORTHEAST OF SIOUX CITY NEAR PRIMGHAR...AND ALSO 30 MILES NORTHEAST OF OTTUMWA NEAR KEOTA. SOME OF THESE STORMS WERE PRODUCING VERY HEAVY RAIN...FREQUENT LIGHTNING AND POSSIBLY SOME SMALL HAIL. THE STORMS AND SHOWERS OVER THE NORTH HALF OF IOWA WERE MOVING NORTHEAST AT 20 MILES AN HOUR. OVER SOUTHEAST IOWA THE STORMS AND SHOWERS WERE MOVING EAST AT AROUND 10 MILES AN HOUR. KALLMAN
Special weather statement, Jul 17, 5:42 AM CDT, 2 minutes before
IAZALL-171140- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 542 AM CDT SAT JUL 17 1993 AT 530 AM CDT...WIDELY SCATTERED STRONG THUNDERSTORMS AND SCATTERED SHOWERS WERE OCCURRING OVER THE NORTHEAST TWO-THIRDS OF IOWA...GENERALLY NORTHEAST OF A LINE FROM SIOUX CITY TO THE IOWA/MISSOURI BORDER SOUTH OF OTTUMWA. WIDELY SCATTERED STRONG STORMS WITH HEAVY RAIN WERE LOCATED IN A 40 MILE WIDE BAND CENTERED FROM 15 MILES NORTH OF DES MOINES TO 30 MILES NORTHWEST OF MASON CITY. ANOTHER AREA OF STRONG STORMS WAS 30 MILES WIDE AND CENTERED FROM 25 MILES SOUTH OF SPENCER NEAR STORM LAKE TO 25 MILES NORTHWEST OF SPENCER AT THE IOWA/MINNESOTA BORDER. THE STORMS WERE PRODUCING VERY HEAVY RAIN...AS WELL AS FREQUENT LIGHTNING AND POSSIBLY SMALL HAIL. MOVEMENT WAS NORTHEAST AT 25 MILES AN HOUR...EXCEPT OVER SOUTHEAST IOWA WHERE THE STORMS AND SHOWERS WERE MOVING EAST AT 15 MILES AN HOUR. / KALLMAN
Special weather statement, Jul 17, 5:42 AM CDT, 2 minutes before
IAZALL-171140- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 542 AM CDT SAT JUL 17 1993 AT 530 AM CDT...WIDELY SCATTERED STRONG THUNDERSTORMS AND SCATTERED SHOWERS WERE OCCURRING OVER THE NORTHEAST TWO-THIRDS OF IOWA...GENERALLY NORTHEAST OF A LINE FROM SIOUX CITY TO THE IOWA/MISSOURI BORDER SOUTH OF OTTUMWA. WIDELY SCATTERED STRONG STORMS WITH HEAVY RAIN WERE LOCATED IN A 40 MILE WIDE BAND CENTERED FROM 15 MILES NORTH OF DES MOINES TO 30 MILES NORTHWEST OF MASON CITY. ANOTHER AREA OF STRONG STORMS WAS 30 MILES WIDE AND CENTERED FROM 25 MILES SOUTH OF SPENCER NEAR STORM LAKE TO 25 MILES NORTHWEST OF SPENCER AT THE IOWA/MINNESOTA BORDER. THE STORMS WERE PRODUCING VERY HEAVY RAIN...AS WELL AS FREQUENT LIGHTNING AND POSSIBLY SMALL HAIL. MOVEMENT WAS NORTHEAST AT 25 MILES AN HOUR...EXCEPT OVER SOUTHEAST IOWA WHERE THE STORMS AND SHOWERS WERE MOVING EAST AT 15 MILES AN HOUR. / KALLMAN
The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 17, 6:35 AM CDT | Flash Flood Warning | DMX | Hardin, Marshall | 3 hr |
| Jul 17, 9:20 AM CDT | Flash Flood Warning | DMX | Polk | 3 hr |
| Jul 17, 2:00 PM CDT | Flash Flood Warning | DMX | Marshall | 4 hr |
| Jul 17, 3:42 PM CDT | Severe Thunderstorm Warning | DMX | Benton | 33 min |
| Jul 17, 5:00 PM CDT | Severe Thunderstorm Warning | DMX | Linn | 30 min |
| Jul 17, 6:03 PM CDT | Flash Flood Warning | DMX | Buchanan | 3 hr |
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.