Alert archive / Iowa / Flash Flood Warnings in 1996

Flash Flood Warning 3, NWS Sioux Falls, SD

June 20, 1996Plymouth County, Iowa

NWS Sioux Falls, SD issued this flash flood warning at Jun 20, 1996, 11:06 PM CDT for Plymouth County, Iowa. It was in force for 114 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: Jun 20, 1996, 11:06 PM CDT (04:06 UTC)
Expired: Jun 21, 1996, 1:00 AM CDT
In force: 114 min
Issued by: NWS Sioux Falls, SD
Area: Whole counties

County Plymouth County, IA

The radar

The Sioux Falls radar (KFSD), 103 km from the middle of the area, began a volume at 04:06 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 nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 4.1 hours before the alert went out and 158 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 2363 J/kg
Mixed-layer CIN: -22 J/kg
Mixed-layer LCL: 1424 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 112 m²/s²
0-3 km storm-relative helicity: 276 m²/s²
Significant tornado parameter: 2.1
Supercell composite: 19.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KFSD 210407
FFWFSD
IAC149-210600-

BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1106 PM CDT THU JUN 20 1996

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS SD HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL 100 AM CDT
FOR PEOPLE IN THE FOLLOWING COUNTY...

IN NORTHWEST IOWA

   ...PLYMOUTH COUNTY
 
AT 1055 PM CDT RAINFALL OF 1.2 INCHES IN 15 MINUTES WERE REPORTED AT
THE PLYMOUTH COUNTY EMERGENCY OPERATIONS CENTER IN LEMARS BRINGING
THEIR TOTAL RAINFALL SINCE 9 AM TO 6 INCHES.  SIOUX FALLS
DOPPLER RADAR ESTIMATES THAT 1 TO 3 INCHES OF RAIN HAS FALLEN SINCE
8 PM.

THE INTERSECTION OF HIGHWAYS 75 AND 3 IN LEMARS WAS REPORTED
UNDERWATER AS WELL AS SECTIONS OF HIGHWAY 75 SOUTH TOWARD SIOUX
CITY.  CREEKS COUNTY WIDE WERE REPORTED OUT OF THEIR BANKS.

OCCASIONAL THUNDERSTORMS ARE EXPECTED TO CONTINUE IN THE PLYMOUTH
COUNTY AREA THROUGH 1 AM. ANY ADDITIONAL RAINFALL WILL AGGREVATE THE
CURRENT FLOODING SITUATION.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGER OF FLOODING   DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER
COVERS THE ROADWAY.  THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR
CAR TO CROSS SAFELY.  VEHICLES CAUGHT IN RISING WATER SHOULD BE
ABANDONED QUICKLY.  MOVE TO HIGHER GROUND.

RUBY/CHAPMAN

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, Jun 20, 10:11 PM CDT, 55 minutes before

SDZ050-057>071-210400-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1011 PM CDT THU JUN 20 1996

...THE TORNADO WATCH FOR SOUTHEAST AND SOUTH CENTRAL SOUTH DAKOTA
HAS EXPIRED...

WITH THE THREAT OF SEVERE WEATHER DIMINISHED THE TORNADO WATCH THAT
WAS IN EFFECT FOR SOUTH CENTRAL AND SOUTHEAST SOUTH DAKOTA HAS
EXPIRED. THUNDERSTORMS ARE EXPECTED TO REDEVELOP LATER TONIGHT WITH
HEAVY RAIN THE BIGGEST THREAT FOR THE AREA.  HOWEVER...THERE WILL
STILL BE THE POTENTIAL FOR A FEW OF THE THUNDERSTORMS TO BECOME
SEVERE.

BRYAN

Local storm report, Jun 20, 10:45 PM CDT, 21 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE  SIOUX FALLS SD
1043 PM CDT THU JUN 20 1996

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0220 PM    HOMER                     NE   1.75 INCH HAIL
06/20/96   DAKOTA

0228 PM    1W MISSION                SD   0.75 INCH HAIL
06/20/96   TODD

0300 PM    5 MI N ELK POINT          SD   1.00 INCH HAIL
06/20/96   UNION

0340 PM    SERGEANT BLUFF            IA   1.25 INCH HAIL
06/20/96   WOODBURY

0345 PM    HORNICK                   IA   1.75 INCH HAIL
06/20/96   WOODBURY

0526 PM    ADRIAN                    MN   0.75 INCH HAIL
06/20/96   NOBLES

0603 PM    STICKNEY                  SD   1.75 INCH HAIL
06/20/96   AURORA

0638 PM    MITCHELL                  SD   1.00 INCH HAIL
06/20/96   DAVISON

0640 PM    STORM LAKE                IA   1.75 INCH HAIL
06/20/96   BUENA VISTA

0703 PM    10 MI N MITCHELL          SD  > 1.75 INCH HAIL
06/20/96   DAVISON

0744 PM    2 MI SE LAKESIDE          IA   0.88 INCH HAIL
06/20/96   BUENA VISTA

BR

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 20, 7:17 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee	33 min
Jun 20, 7:42 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista	33 min
Jun 20, 8:31 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth	34 min

Nearby

Flash Flood Warnings in Iowa, 1996 Every flash flood warning in 1996

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.