Alert archive / Iowa / Flash Flood Warnings in 1986

Flash Flood Warning 1, NWS Des Moines, IA

May 9, 1986Dallas County, Polk County, Iowa

NWS Des Moines, IA issued this flash flood warning at May 9, 1986, 8:29 PM CDT for Dallas County, Polk County, Iowa. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: May 9, 1986, 8:29 PM CDT (01:29 UTC)
Expired: May 9, 1986, 11:00 PM CDT
In force: 3 hr
Issued by: NWS Des Moines, IA
Area: Whole counties

Counties Dallas County, IA, Polk County, IA

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 1.5 hours before the alert went out and 217 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 3570 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 72 m²/s²
0-3 km storm-relative helicity: 110 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 100131
FFWDSM
IAC153-049-100400-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
829 PM CDT FRI MAY 9 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A FLASH FLOOD WARNING
EFFECTIVE UNTIL 1100 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES OF

CENTRAL IOWA...WESTERN POLK AND EASTERN DALLAS

A FLASH FLOOD WARNING MEANS FLOODING IS IMINENT OR IS OCCURRING.
TAKE NECESSARY PRECAUTIONS IMMEDIATELY.

AT 815 PM REPORTS WERE BEING RECEIVED OF EXTREMELY HEAVY RAIN IN
NORTHWEST POLK COUNTY AND EASTERN DALLAS COUNTY..THAT WAS RAPIDLY
SWELLING CREEKS AND STREAMS IN THAT AREA.

AT 824 PM RADAR INDICATED THAT THE SAME THUNDERSTORM CELL THAT WAS
PRODUCING THE TORNADOES ON THE BORDER OF POLK AND DALLAS COUNTIES
WAS SLOWING DOWN.  THE HEAVY RAIN ASSOCIATED WITH THIS STORM HAS
CONTINUED EVEN AS THE STORM HAS SLOWED.

PEOPLE IN THE WALNUT CREEK AREA..AND NEAR OTHER CREEKS AND STREAMS
IN THIS VICINITY..SHOULD BE AWARE OF RAPIDLY RISING WATERS.

PEOPLE LIVING IN FLOOD PRONE AREAS SHOULD MOVE TO HIGHER GROUND AT
ONCE.  ACT QUICKLY..AS FLOOD WATERS OFTEN RISE VERY RAPIDLY.

DOWD

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

Local storm report, May 9, 4:01 PM CDT, 4 hours 28 minutes before

SEVERE LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
400 PM CDT FRI MAY 9 1986

ADDITIONAL STORM REPORTS FROM THE SEVERE WEATHER ON MAY 8 1986

330 PM CDT...LARGE BUILDING BEING CONSTRUCTED JUST WEST OF LAKE RATHBUN
             IN APPANOOSE COUNTY WAS DESTROYED BY WIND.

350 PM CDT...SHERIFF OF MONROE COUNTY SAID TORNADO ORIGINALLY REPORTED
             2 MILES SOUTH IF ALBIA THAT TOOK ROOF OFF BUILDING WAS WIND
             DAMAGE.

403 PM CDT...LUCAS COUNTY SHERIFF SAID LIGHT POLES AND TREES WERE BLOWN
             DOWN NEAR THE TOWN OF RUSSELL WHICH IS 7 MILES EAST OF
             CHARITON.

435 PM CDT...ROOF BLOWN OFF MACHINE SHED 2 MILES SOUTHEAST OF KNOXVILLE..
             IN MARION COUNTY.  REPORT FROM COUNTY SHERIFF.
435 PM CDT...2 LARGE TREES BLOWN DOWN ON HOUSE AND BROKE POWER LINES IN
             CARLISLE..JUST SOUTHEAST OF DES MOINES.  REPORT FROM NATIONAL
             WEATHER SERVICE EMPLOYEE.

438 PM CDT...MARION COUNTY SHERIFF REPORTED SEVERAL TREES AND LARGE TREE
             LIMBS DOWN.

440 PM CDT...MARION COUNTY..PELLA POLICE REPORTED SEVERAL TREES AND POWER
             LINES DOWN.

ADAMS

Special weather statement, May 9, 6:47 PM CDT, 1 hour 42 minutes before

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
647 PM CDT FRI MAY 9 1986

...A SEVERE THUNDERSTORMS WATCH IS IN EFFECT FOR A LARGE PART OF IOWA
UNTIL MIDNIGHT...

NO SEVERE WEATHER WAS REPORTED IN THE STATE BETWEEN 545 AND 645 PM CDT

AT 631 PM CDT...
VERY STRONG THUNDERSTORMS WERE SCATTERED OVER CENTRAL IOWA.  THE MOST
INTENSE STORMS WERE LOCATED ABOUT 15 MILES NORTHEAST AND 10 MILES EAST
OF DES MOINES.  THESE STORMS WERE PRODUCING PEA TO MARBLE SIZE HAIL AND
VERY HEAVY RAIN.

MEANWHILE..STRONG THUNDERSTORMS WERE MOVING INTO IOWAS SOUTH CENTRAL
COUNTIES BETWEEN LAMONI AND CENTERVILLE.

IN ADDITION..WIDELY SCATTERED SHOWERS AND THUNDERSHOWERS DOT THE NORTH
CENTRAL AND NORTHEAST COUNTIES OF THE STATE.
\
ALL OF THE RAIN WAS MOVING NORTH AT 25 MILES AN HOUR.

SCHUMACHER/SIECZYNSKI

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 9, 7:09 PM CDT	Severe Thunderstorm Warning	DMX	Dallas, Polk	21 min
May 9, 7:15 PM CDT	Tornado Warning	DMX	Dallas, Polk	30 min
May 9, 7:45 PM CDT	Tornado Warning	DMX	Dallas, Polk	30 min
May 9, 7:53 PM CDT	Severe Thunderstorm Warning	DMX	Webster	37 min
May 9, 7:58 PM CDT	Tornado Warning	DMX	Webster	32 min
May 9, 8:16 PM CDT	Tornado Warning	DMX	Dallas, Polk	44 min
May 9, 8:47 PM CDT	Tornado Warning	DMX	Boone	43 min
May 9, 9:02 PM CDT	Tornado Warning	DMX	Dallas, Polk	28 min
May 9, 10:08 PM CDT	Severe Thunderstorm Warning	DMX	Ringgold, Taylor	22 min

Nearby

Flash Flood Warnings in Iowa, 1986 Every flash flood warning in 1986

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.