Alert archive / Iowa / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 170, NWS Des Moines, IA

July 6, 2003Audubon County, Cass County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 6, 2003, 12:56 AM CDT for Audubon County, Cass County, Iowa. It was in force for 49 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 6, 2003, 12:56 AM CDT (05:56 UTC)
Expired: Jul 6, 2003, 1:45 AM CDT
In force: 49 min
Issued by: NWS Des Moines, IA
Area: Counties, with a storm outline in the text

Counties Audubon County, IA, Cass County, IA

The radar

The Omaha radar (KOAX), 101 km from the middle of the area, began a volume at 05:59 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.

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.

Issued	Product	Office	Lasted
Jul 5, 11:50 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 5.9 hours before the alert went out and 101 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: 2840 J/kg
Mixed-layer CIN: -46 J/kg
Mixed-layer LCL: 1471 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 133 m²/s²
0-3 km storm-relative helicity: 232 m²/s²
Significant tornado parameter: 1.8
Supercell composite: 11.5

Open this sounding in Storm Lab

The text

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

290 
WUUS53 KDMX 060556
SVRDMX
IAC009-029-060645-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1256 AM CDT SUN JUL 6 2003

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CASS COUNTY IN SOUTHWEST IOWA
  AUDUBON COUNTY IN WEST CENTRAL IOWA

* UNTIL 145 AM CDT

* AT 1252 AM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS FROM 25 MILES NORTHWEST OF KIMBALLTON
  TO 19 MILES WEST OF GRISWOLD...OR FROM 46 MILES NORTHEAST OF
  COUNCIL BLUFFS TO 19 MILES EAST OF COUNCIL BLUFFS...MOVING EAST AT
  55 MPH.

* SEVERE THUNDERSTORMS WILL BE...

  NEAR GRISWOLD AROUND 110 AM...
  NEAR ATLANTIC AROUND 115 AM...
  NEAR GRAY AROUND 120 AM...
  NEAR WIOTA AROUND 125 AM...
  NEAR ANITA MUNICIPAL AIRPORT AROUND 130 AM AND
  NEAR MASSENA AROUND 135 AM.

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

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 500 AM SUNDAY
MORNING FOR SOUTHERN IOWA.

LAT...LON 4187 9555 4154 9551 4112 9561 4117 9471
          4152 9472 4186 9474


$$

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 5, 9:00 PM CDT, 3 hours 56 minutes earlier.

Area forecast discussion, Jul 5, 9:00 PM CDT, 3 hours 56 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
900 PM CDT SAT JUL 5 2003

CUR COMPLEX OVR NEB SIG CONCERN.  PLAN TO ISSUE FFA FM U.S. HWY 30
TO U.S. HWY 20 CORRIDOR.

.DSM...FFA TNGT CNTRL THIRD OF IA

MS JUL 03

Hazardous weather outlook, Jul 5, 10:45 PM CDT, 2 hours 11 minutes before

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-071100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
1045 PM CDT SAT JUL 5 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL IOWA.

.DAY ONE...TONIGHT
AN AREA OF THUNDERSTORMS OVER NEBRASKA WILL ADVANCE EAST INTO IOWA
OVERNIGHT.  IN ADDITION...THERE IS THE POSSIBILITY OF STRONG
THUNDERSTORM DEVELOPMENT OVER SOUTHEAST SOUTH DAKOTA INTO SOUTHWEST
MINNESOTA LATER TONIGHT.  THESE TWO AREAS WILL LIKELY MOVE INTO IOWA
DURING THE PREDAWN HOURS.  THE THREAT OF THUNDERSTORMS WILL INCREASE
OVER THE WESTERN PART OF THE DES MOINES WARNING AREA AROUND 300 AM
OR SO...THEN SPREAD EAST INTO THE MORNING HOURS.  THE MAIN THREAT
FROM THESE STORMS IS FOR DAMAGING WINDS AND HAIL.  ISOLATED
LOCATIONS COULD RECEIVE ONE TO TWO INCHES OF RAINFALL...BUT HEAVY
RAINFALL WILL BE ISOLATED.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

A FRONT STRETCHED ACROSS SOUTHERN IOWA WILL PROVIDE THE FOCUS FOR
RENEWED SHOWER AND THUNDERSTORM DEVELOPMENT MONDAY AFTERNOON. A FEW
SUPERCELL THUNDERSTORMS ARE POSSIBLE...WITH LARGE HAIL AND DAMAGING
WINDS. THERE IS ALSO A CHANCE FOR ANOTHER THUNDERSTORM COMPLEX TO
MOVE ACROSS CENTRAL IOWA MONDAY NIGHT...WITH THE THREAT OF MORE
LOCALLY HEAVY RAIN AND DAMAGING WINDS. CENTRAL IOWA WILL REMAIN
UNDER A SLIGHT RISK FOR SEVERE THUNDERSTORMS TUESDAY
AFTERNOON...MAINLY ACROSS AREAS SOUTH OF HIGHWAY 30. THUNDERSTORMS
ARE POSSIBLE OVER CENTRAL IOWA AGAIN ON WEDNESDAY. LITTLE OR NO
PRECIPITATION IS EXPECTED THURSDAY THROUGH SATURDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS LIKELY TONIGHT NORTH OF HIGHWAY 20...AND
POSSIBLE SOUTH OF HIGHWAY 20. ACTIVATION IS POSSIBLE AGAIN MONDAY
AFTERNOON AND NIGHT OVER ALL OF CENTRAL IOWA.
&&

MORE INFORMATION CAN BE OBTAINED AT WWW.CRH.NOAA.GOV/DMX (ALL LOWER
CASE).

MS JUL 03

In the hours before

Local storm report, Jul 5, 9:33 PM CDT, 3 hours 23 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
0933 PM CDT SAT JUL 05 2003

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

0915 PM    3 SE MALOY                IA   60 MPH TSTORM WIND
07/05/03   RINGGOLD                       4 INCH DIAMETER TREES
                                          DOWNED. TRAINED SPOTTER
                                          REPORT.

BF

Local storm report, Jul 5, 9:36 PM CDT, 3 hours 20 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
0936 PM CDT SAT JUL 05 2003

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

0920 PM    2 NE REDDING              IA   0.88 IN HAIL
07/05/03   RINGGOLD                       TRAINED SPOTTER REPORT.

BF

Local storm report, Jul 5, 9:38 PM CDT, 3 hours 18 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
0938 PM CDT SAT JUL 05 2003

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

0806 PM    ALLERTON                  IA   70 MPH TSTORM WIND
07/05/03   WAYNE                          TREE DOWN ON HOUSE.

BF

Local storm report, Jul 5, 9:41 PM CDT, 3 hours 15 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
0941 PM CDT SAT JUL 05 2003

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

0819 PM    SEYMOUR                   IA   WIND DAMAGE
07/05/03   WAYNE                          12 INCH TREE LIMB REMOVED
                                          FROM HIGHWAY 55.

BF

Local storm report, Jul 5, 11:50 PM CDT, 1 hour 6 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
1150 PM CDT SAT JUL 05 2003

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

1251 AM    10 NE AMES                IA   WIND DAMAGE
07/05/03   STORY                          6 TO 7 INCH TREES DOWN.

BF

Local storm report, Jul 5, 11:53 PM CDT, 1 hour 3 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
1153 PM CDT SAT JUL 05 2003

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

1250 AM    AMES                      IA   WIND DAMAGE
07/05/03   STORY                          NORTH SIDE OF IOWA ST
                                          CAMPUS. 12 INCH TREE DOWN.
                                          REPORTED BY AMATEUR RADIO.

BF

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 5, 7:27 PM CDT	Severe Thunderstorm Warning	DMX	Decatur	63 min
Jul 5, 8:09 PM CDT	Severe Thunderstorm Warning	DMX	Wayne	36 min
Jul 5, 9:04 PM CDT	Severe Thunderstorm Warning	DMX	Ringgold	41 min
Jul 6, 12:09 AM CDT	Severe Thunderstorm Warning	DMX	Crawford	66 min
Jul 6, 1:25 AM CDT	Severe Thunderstorm Warning	DMX	Adair, Guthrie	50 min
Jul 6, 2:13 AM CDT	Severe Thunderstorm Warning	DMX	Hardin	47 min
Jul 6, 4:11 AM CDT	Severe Thunderstorm Warning	DMX	Cass	34 min
Jul 6, 7:20 AM CDT	Severe Thunderstorm Warning	DMX	Dallas	40 min
Jul 6, 7:50 AM CDT	Severe Thunderstorm Warning	DMX	Madison	40 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2003 Every severe thunderstorm warning in 2003

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.