Alert archive / Iowa / Flash Flood Warnings in 2012
Flash Flood Warning 12, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this flash flood warning at May 27, 2012, 7:22 PM CDT for Lyon County, Plymouth County, Sioux County, Iowa; Clay County, Lincoln County, Union County, South Dakota. It was in force for 7 hr. 2 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- May 27, 2012, 7:22 PM CDT (00:22 UTC)
- Expired
- May 28, 2012, 2:13 AM CDT
- In force
- 7 hr
- Issued by
- NWS Sioux Falls, SD
- Area
- Storm-based polygon
- Flood severity
- None
Counties Lyon County, IA, Plymouth County, IA, Sioux County, IA, Clay County, SD, Lincoln County, SD, Union County, SD
The radar
The Sioux Falls radar (KFSD), 54 km from the middle of the area, began a volume at 00:26 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| May 27, 8:02 PM CDT | FLASH FLOOD | Rock Valley, IA | WATTER RUNNING RAPIDLY DOWN THE ROAD. |
| May 27, 8:30 PM CDT | FLASH FLOOD | Rock Valley, IA | WATER OVER ROAD MAKING MAINSTREET IMPASSIBLE AND HIGHWAY 18 IS DOWN TO ONE LANE |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 0.4 hours before the alert went out and 202 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
- 849 J/kg
- Mixed-layer CIN
- -92 J/kg
- Mixed-layer LCL
- 2094 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 81 m²/s²
- 0-3 km storm-relative helicity
- 138 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.4
The text
As transmitted, in the capitals the NWS used until 2016.
107 WGUS53 KFSD 280022 FFWFSD IAC119-149-167-SDC027-083-127-280630- /O.NEW.KFSD.FF.W.0012.120528T0022Z-120528T0630Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE SIOUX FALLS SD 722 PM CDT SUN MAY 27 2012 THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A * FLASH FLOOD WARNING FOR... EASTERN CLAY COUNTY IN SOUTHEAST SOUTH DAKOTA NORTHERN UNION COUNTY IN SOUTHEAST SOUTH DAKOTA NORTHWESTERN PLYMOUTH COUNTY IN NORTHWEST IOWA SOUTHEASTERN LINCOLN COUNTY IN SOUTHEAST SOUTH DAKOTA SOUTHWESTERN LYON COUNTY IN NORTHWEST IOWA WESTERN SIOUX COUNTY IN NORTHWEST IOWA * UNTIL 130 AM CDT MONDAY * AT 716 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. RAIN FALL OF ONE TO ONE AND A HALF INCHES FELL EARLIER THIS EVENING AND AN ADDITIONAL ONE TO TWO INCHES WILL BE POSSIBLE. THIS WARNING INCLUDES NEWTON HILLS STATE PARK. * RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE... BERESFORD...CANTON...HAWARDEN...AKRON...ALCESTER...ALVORD...DOON... FAIRVIEW...HUDSON...INWOOD...NEWTON HILLS STATE PARK AND ROCK VALLEY. PRECAUTIONARY/PREPAREDNESS ACTIONS... DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. FLOODING IS OCCURRING OR IS IMMINENT. IT IS IMPORTANT TO KNOW WHERE YOU ARE RELATIVE TO STREAMS...RIVERS...OR CREEKS WHICH CAN BECOME KILLERS IN HEAVY RAINS. CAMPERS AND HIKERS SHOULD AVOID STREAMS OR CREEKS. && LAT...LON 4339 9616 4270 9648 4282 9702 4335 9665 $$
2 follow-up statements
286 WGUS53 KFSD 280325 FFWFSD IAC119-149-167-SDC027-083-127-280730- /O.EXT.KFSD.FF.W.0012.000000T0000Z-120528T0730Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE SIOUX FALLS SD 1025 PM CDT SUN MAY 27 2012 THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS EXTENDED THE * FLASH FLOOD WARNING FOR... EASTERN CLAY COUNTY IN SOUTHEAST SOUTH DAKOTA NORTHERN UNION COUNTY IN SOUTHEAST SOUTH DAKOTA NORTHWESTERN PLYMOUTH COUNTY IN NORTHWEST IOWA SOUTHEASTERN LINCOLN COUNTY IN SOUTHEAST SOUTH DAKOTA SOUTHWESTERN LYON COUNTY IN NORTHWEST IOWA WESTERN SIOUX COUNTY IN NORTHWEST IOWA * UNTIL 230 AM CDT * AT 1016 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. RADAR INDICATES ONE TO THREE INCHES OF RAINFALL HAS FALLEN OVER THE WARNED AREA. THIS COMBINED WITH TWO TO FOUR INCHES OF RAINFALL EARLY THIS WEEK WILL CREATE FLOODING ACROSS THE AREA. AN ADDITIONAL HALF AN INCH TO INCH OF RAINFALL IS EXPECTED ACROSS THE AREA. * RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE... BERESFORD...CANTON...HAWARDEN...AKRON...ALCESTER...ALVORD...DOON... FAIRVIEW...HUDSON...INWOOD...NEWTON HILLS STATE PARK AND ROCK VALLEY. PRECAUTIONARY/PREPAREDNESS ACTIONS... BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. DO NOT ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING. FLOODING IS OCCURRING OR IS IMMINENT. IT IS IMPORTANT TO KNOW WHERE YOU ARE RELATIVE TO STREAMS...RIVERS...OR CREEKS WHICH CAN BECOME KILLERS IN HEAVY RAINS. CAMPERS AND HIKERS SHOULD AVOID STREAMS OR CREEKS. && LAT...LON 4339 9616 4270 9648 4282 9702 4335 9665 $$ BT
523 WGUS73 KFSD 280713 FFSFSD FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 213 AM CDT MON MAY 28 2012 IAC119-149-167-SDC027-083-127-280728- /O.CAN.KFSD.FF.W.0012.000000T0000Z-120528T0730Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ SIOUX IA-PLYMOUTH IA-LYON IA-LINCOLN SD-CLAY SD-UNION SD- 213 AM CDT MON MAY 28 2012 ...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR NORTHERN UNION... EASTERN CLAY...SOUTHEASTERN LINCOLN...SOUTHWESTERN LYON... NORTHWESTERN PLYMOUTH AND WESTERN SIOUX COUNTIES IS CANCELLED... EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. STREAMS AND CREEKS IN THE WARNED AREA HAVE RECEDED OR WERE BEGINNING TO RECEDE...ENDING THE FLOOD THREAT. IF FLOODING WAS OBSERVED PLEASE RELAY YOUR REPORT TO LOCAL LAW ENFORCEMENT OR TO THE NATIONAL WEATHER SERVICE IN SIOUX FALLS. LAT...LON 4339 9616 4270 9648 4282 9702 4335 9665 $$ CHENARD
The office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 27, 7:11 PM CDT | Severe Thunderstorm Warning | FSD | Plymouth, Sioux | 34 min |
| May 27, 7:31 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, Plymouth, Sioux | 29 min |
| May 27, 7:54 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, O'Brien, Osceola, Sioux | 36 min |
| May 27, 8:19 PM CDT | Flash Flood Warning | FSD | Lyon, Osceola | 7 hr |
| May 27, 8:54 PM CDT | Severe Thunderstorm Warning | FSD | Dickinson | 36 min |
| May 27, 9:18 PM CDT | Severe Thunderstorm Warning | FSD | Plymouth | 27 min |
| May 27, 9:42 PM CDT | Severe Thunderstorm Warning | FSD | Plymouth, Woodbury | 10 min |
| May 28, 5:35 AM CDT | River Flood Warning | FSD | Lyon | 52 hr |
| May 28, 5:35 AM CDT | River Flood Warning | FSD | Clay | 71 hr |
| May 28, 5:35 AM CDT | River Flood Warning | FSD | Clay | 8 days |
| May 28, 5:35 AM CDT | River Flood Warning | FSD | Buena Vista, Clay | 9 days |
| May 27, 9:32 PM CDT | Flash Flood Warning | FSD | Clay, Union | 4 hr |
Nearby
Flash Flood Warnings in Iowa, 2012Flash Flood Warnings in South Dakota, 2012Every flash flood warning in 2012
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.