Alert archive / Iowa / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 160, NWS Des Moines, IA

July 26, 2002Marion County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 26, 2002, 10:24 PM CDT for Marion County, Iowa. It was in force for 36 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 26, 2002, 10:24 PM CDT (03:24 UTC)
Expired
Jul 26, 2002, 11:00 PM CDT
In force
36 min
Issued by
NWS Des Moines, IA
Area
Counties, with a storm outline in the text

County Marion County, IA

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 26, 9:40 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 3.4 hours before the alert went out and 223 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-pSkew-T log-p diagram, Davenport, at 00:00Z on 2002-07-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1442 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2002-07-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
1442 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
1194 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
110 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.4

Open this sounding in Storm Lab

The text

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

448 
WUUS53 KDMX 270324
SVRDSM
IAC125-270400-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1024 PM CDT FRI JUL 26 2002

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  MARION COUNTY IN SOUTH CENTRAL IOWA

* UNTIL 1100 PM CDT

* AT 1019 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 4 MILES SOUTHWEST OF KNOXVILLE...OR ABOUT 30
  MILES SOUTHEAST OF DES MOINES...MOVING NORTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE...
  NEAR KNOXVILLE AT 1030 PM
  6 MILES NORTHWEST OF HARVEY AROUND 1040 PM AND
  NEAR PELLA AROUND 1050 PM.

HAIL UP TO THE SIZE OF NICKELS IS LIKELY IN THE WARNED AREA.

DAMAGING WINDS OF 60 TO 70 MILES AN HOUR ARE LIKELY IN THE WARNED
AREA.

MOVE TO AN INTERIOR ROOM AND STAY AWAY FROM WINDOWS. IF YOU LIVE IN A
MOBILE HOME...SEEK SHELTER IN A STURDY BUILDING.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 300 AM SATURDAY
MORNING FOR IOWA.

LAT...LON 4150 9333 4117 9333 4118 9289 4150 9290

JOHNSON

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Des Moines, IA wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 26, 10:09 PM CDT, 15 minutes earlier.

Area forecast discussion, Jul 26, 10:09 PM CDT, 15 minutes before
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DES MOINES IA
1009 PM  CDT FRI JUL 26 2002

QUESTIONS FOR UPDATE WERE SVR AND HVY RAIN POTENTIAL.  SHALLOW AND
DEEP SHEAR CERTAINLY SUFFICIENT FOR EITHER SUPERCELLS OR MULTICELLS
WITH EMBEDDED BOWS OVNGT BUT MAY BE LEANING TWRD THE LATER.  HVY
RAINS COULD BE A GREATER PROBLEM.  KOAX SOUNDING MAY BE CONTAMINATED
SOMEWHAT BUT DEPICTS PWS AOA 2 INCHES...A K INDEX ARND 40...AND A
DEEP WRM CLD LYR.  02Z SFC ANLYS PLACES LOW OVR N CNTRL KS WITH
WRMFNT ALG KS/NE BORDER INTO NRN MON.  PRES FALL CNTR NOW SHIFTING
NWD INTO SD/NE.  RADAR MOSAIC CONTS TO SHOW REGENERATION UPSTREAM
ACRS ERN NE SO TRAINING CELLS WL BE A CONCERN.  00Z SFC GEOSTROPHIC
WNDS PLACE 25-50KT LOW LVL JET INTO FAR NRN KS...AND 00Z RUC/ETA
SOLTIONS VEER THIS OVNGT ACRS SRN IA.  KEPT HVY RAIN MENTION IN ZNS
AND CONSIDERED FLOOD WATCH BUT DID NOT FEEL LOW FLASH FLOOD GUIDANCE
VALUES WHERE WDSPRD ENOUGH TO WARRANT ATTM.  THIS MAY BE SPCLLY TRUE
IF LOW LVL BACLIN ZN LIFTS NWD AS MDLS DEPICT.  MDLS MAY BE A BIT
TOO FAR N...BUT CONSIDERING PRES FALLS AND RADAR TRENDS...HEAVIEST
RAINS MAY LIFT INTO CNTRL PTNS AWAY FM LOWEST FLASH FLOOD GUIDANCE
VALUES.  NO SGFNT CHGS TO RMNDR OF FCST.

.DSM...NONE

SMALL

In the hours before

Local storm report, Jul 26, 9:04 PM CDT, 1 hour 20 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
904 PM CDT FRI JUL 26 2002

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

0900 PM    2 S NEW MARKET            IA   1.75 INCH HAIL
07/26/02   TAYLOR                         REPORTED BY EMERGENCY
                                          MANAGEMENT.

0900 PM    6 S NEW MARKET            IA   1 INCH HAIL
07/26/02   TAYLOR                         REPORTED BY EMERGENCY
                                          MANAGEMENT.
Local storm report, Jul 26, 9:21 PM CDT, 1 hour 3 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
921 PM CDT FRI JUL 26 2002

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

0900 PM    5 W BEDFORD               IA   1.75 INCH HAIL
07/26/02   TAYLOR                         REPORTED BY LAW
                                          ENFORCEMENT OFFICIAL.

0920 PM    BEDFORD                   IA   1.75 INCH HAIL
07/26/02   TAYLOR                         REPORTED BY LAW
                                          ENFORCEMENT OFFICIAL.
Local storm report, Jul 26, 9:22 PM CDT, 1 hour 2 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
922 PM CDT FRI JUL 26 2002

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

0920 PM    BEDFORD                   IA   1 INCH HAIL
07/26/02   TAYLOR                         REPORTED BY EMERGENCY
                                          MANAGEMENT.
Local storm report, Jul 26, 9:30 PM CDT, 54 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
930 PM CDT FRI JUL 26 2002

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

0929 PM    5 SE NEW MARKET           IA   TORNADO
07/26/02   TAYLOR                         REPORTED BY STORM
                                          SPOTTER.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 26, 8:30 PM CDTSevere Thunderstorm WarningDMXTaylor60 min
Jul 26, 8:58 PM CDTTornado WarningDMXTaylor47 min
Jul 26, 11:43 PM CDTSevere Thunderstorm WarningDMXJasper47 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2002Every severe thunderstorm warning in 2002

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.