Alert archive / Iowa / Severe Thunderstorm Warnings in 2004

Severe Thunderstorm Warning 169, NWS Des Moines, IA

May 23, 2004Mahaska County, Poweshiek County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 23, 2004, 12:35 AM CDT for Mahaska County, Poweshiek County, Iowa. It was in force for 55 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: May 23, 2004, 12:35 AM CDT (05:35 UTC)
Expired: May 23, 2004, 1:30 AM CDT
In force: 55 min
Issued by: NWS Des Moines, IA
Area: Counties, with a storm outline in the text

Counties Mahaska County, IA, Poweshiek County, IA

The radar

The Des Moines radar (KDMX), 95 km from the middle of the area, began a volume at 05:35 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
May 22, 10:40 PM CDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 5.6 hours before the alert went out and 314 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: 2882 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 1091 m above ground
0-6 km bulk shear: 64 kt
0-1 km storm-relative helicity: 51 m²/s²
0-3 km storm-relative helicity: 260 m²/s²
Significant tornado parameter: 4.2
Supercell composite: 16.7

Open this sounding in Storm Lab

The text

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

741 
WUUS53 KDMX 230535
SVRDMX
IAC123-157-230630-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1235 AM CDT SUN MAY 23 2004

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  POWESHIEK COUNTY IN CENTRAL IOWA
  MAHASKA COUNTY IN SOUTH CENTRAL IOWA

* UNTIL 130 AM CDT

* AT 1230 AM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS FROM 8 MILES NORTHWEST OF GRINNELL TO
  21 MILES SOUTHWEST OF LEIGHTON...OR FROM 45 MILES NORTHEAST OF DES
  MOINES TO 36 MILES SOUTHEAST OF DES MOINES...MOVING EAST AT 50 MPH.

* SEVERE THUNDERSTORMS WILL BE...

  NEAR SEARSBORO AROUND 1240 AM...
  NEAR NEW SHARON AROUND 1245 AM...
  NEAR MONTEZUMA AROUND 1250 AM...
  NEAR BROOKLYN AROUND 1255 AM...
  NEAR KEOMAH VILLAGE AROUND 100 AM AND
  NEAR OSKALOOSA MUNICIPAL AIRPORT AROUND 105 AM.

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

GO TO A BASEMENT OR SMALL INTERIOR ROOM. EXTENSIVE DAMAGE IS LIKELY.
EVACUATE MOBILE HOMES...AND SEEK SHELTER IN A STURDY BUILDING. SEVERE
STRAIGHT LINE WINDS CAN SOUND LIKE A TORNADO...AND PRODUCE SIMILAR
DAMAGE.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 4 AM CDT SUNDAY MORNING FOR 
IOWA.

LAT...LON 4185 9276 4151 9274 4150 9286 4117 9287
      4117 9243 4152 9244 4153 9232 4184 9232

$$

COGIL

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 May 22, 2:09 PM CDT, 10 hours 26 minutes earlier.

Area forecast discussion, May 22, 2:09 PM CDT, 10 hours 26 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
209 PM CDT SAT MAY 22 2004

.DISCUSSION...
MAIN CONCERNS FOR EARLY IN THE FORECAST PERIOD WILL BE CONVECTION
THROUGH MONDAY. TODAY OUTFLOW BOUNDARY FROM MORNING CONVECTION
BEGINNING TO ERODE OVER NORTHERN MISSOURI WITH A MORE SOUTHERLY PUSH
BECOMING APPARENT. NEXT IN ROUND OF SHORTWAVES NOW ENTERING MIDWEST.
STATIONARY BOUNDARY OVER NORTHERN IOWA BEGINNING TO SAG SOUTH WITH
BOUNDARIES PRIMED TO CONVERGE. EXPLOSIVE THUNDERSTORM DEVELOPMENT
APPEARS LIKELY AND FROM 18Z OAX SOUNDING...CAP IS ERODING.
SUPERCELLS ARE LIKELY WITHIN THE FIRST SEVERAL HOURS OF INITIATION
LATE THIS AFTERNOON AND EVENING. LARGE HAIL AND TORNADOES WILL BE
THE MAIN THREATS EARLY ON. HEAVY RAIN WILL BE A CONCERN WITH THE
POSSIBILITY OF TRAINING STORMS EARLY. 65-70KT 850MB JET CRANKS UP
TONIGHT WITH GOOD CONVERGENCE OVER IOWA AND PLENTY OF MOISTURE FEED.
CONVECTION SHOULD FORM INTO AN MCS AND TRAVEL ACROSS THE
NORTHWESTERN 2/3 OF THE FORECAST AREA. WIDESPREAD 1-2 INCH AMOUNTS
LIKELY WITH LOCALLY HEAVIER POSSIBLE.  LOW TRACKS ACROSS CNTRL IA
SUNDAY...POSSIBLE THUNDERSTORMS DEVELOPING ALONG COLD FRONT ACROSS
EAST. MORE THUNDERSTORMS EXPECTED MONDAY AS NEXT SYSTEM ARRIVES.

ACTIVITY FINALLY COMES TO AN END BY TUESDAY WITH COOLER AND DRY
CONDITIONS EXPECTED. KEPT NEXT CHANCE FOR PRECIPITATION FRIDAY.
ENSEMBLES NOT IN AGREEMENT ON SHORTWAVE TOWARDS THE END OF THE WEEK
AND REMAIN CONSISTENT FOR END OF EXTENDED PERIOD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...FLOOD WATCH TONIGHT NORTH OF
INTERSTATE 80.

&&

DONAVON

Hazardous weather outlook, May 22, 3:27 PM CDT, 9 hours 8 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
327 PM CDT SAT MAY 22 2004

IAZ004>007-015>017-024>028-036>039-048>050-060>062-231100-
BLACK HAWK-BREMER-BUTLER-CERRO GORDO-EMMET-FRANKLIN-GRUNDY-HAMILTON-
HANCOCK-HARDIN-HUMBOLDT-JASPER-KOSSUTH-MARSHALL-PALO ALTO-POLK-
POWESHIEK-STORY-TAMA-WINNEBAGO-WORTH-WRIGHT-
327 PM CDT SAT MAY 22 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MUCH OF CENTRAL AND NORTHERN
IOWA...NORTH AND EAST OF A LINE FROM EMMETSBURG...TO DES MOINES...TO
GRINNELL.

.DAY ONE...TONIGHT

THERE IS A MODERATE RISK OF SEVERE WEATHER FROM 6 PM TONIGHT
THROUGH THE REST OF THE NIGHT.  THREATS INCLUDE VERY LARGE HAIL AND
DAMAGING STRAIGHT LINE WINDS. ISOLATED TORNADOES ARE ALSO POSSIBLE
DURING THE EVENING HOURS. FLASH FLOODING IS ALSO POSSIBLE...
ESPECIALLY ACROSS AREAS ALONG AND NORTH OF HIGHWAY 20 THAT WERE HARD
HIT BY RECENT RAINS. ISOLATED 3 TO 5 INCH RAINFALL TOTALS ARE
POSSIBLE BY SUNDAY MORNING.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

A THUNDERSTORM COMPLEX...WITH SOME EMBEDDED SEVERE
THUNDERSTORMS POSSIBLE...WILL LIKELY BE ONGOING EARLY SUNDAY
MORNING. SEVERE WEATHER IS POSSIBLE AGAIN SUNDAY AFTERNOON AND
MONDAY AFTERNOON AND NIGHT.

.SPOTTER ACTIVATION STATEMENT...

SPOTTER ACTIVATION WILL BE NEEDED TONIGHT FOR BOTH SEVERE WEATHER AND
FLOODING REPORTS. SPOTTER ACTIVATION MAY ALSO BE NEEDED AGAIN ON
SUNDAY AND MONDAY.

IAZ023-033>035-044>047-057>059-231100-
AUDUBON-BOONE-CALHOUN-CARROLL-CRAWFORD-DALLAS-GREENE-GUTHRIE-
POCAHONTAS-SAC-WEBSTER-
327 PM CDT SAT MAY 22 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR A PORTION OF WEST
CENTRAL INTO CENTRAL IOWA...ALONG AND WEST OF A LINE FROM AUDUBON...
TO PERRY...TO POCAHONTAS.

.DAY ONE...TONIGHT

THERE IS A MODERATE RISK OF SEVERE WEATHER FROM 600 PM THROUGH
THE NIGHT. THREATS INCLUDE VERY LARGE HAIL AND DAMAGING STRAIGHT LINE
WINDS. CONDITIONS ARE ALSO VERY FAVORABLE FOR TORNADOES DURING THE
EVENING. FLASH FLOODING IS ALSO POSSIBLE...ESPECIALLY ACROSS AREAS
ALONG AND NORTH OF HIGHWAY 20 THAT WERE HARD HIT BY RECENT RAINS.
ISOLATED 3 TO 5 INCH RAINFALL TOTALS ARE POSSIBLE BY SUNDAY MORNING.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SEVERE THUNDERSTORMS ARE POSSIBLE MONDAY AFTERNOON AND NIGHT.

.SPOTTER ACTIVATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED TONIGHT FOR BOTH SEVERE
WEATHER AND FLOODING REPORTS. SPOTTER ACTIVATION MAY ALSO BE NEEDED
MONDAY AFTERNOON AND NIGHT.

IAZ073>075-084>086-092>097-231100-
APPANOOSE-DAVIS-DECATUR-LUCAS-MAHASKA-MARION-MONROE-RINGGOLD-TAYLOR-
WAPELLO-WARREN-WAYNE-
327 PM CDT SAT MAY 22 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MUCH OF SOUTHERN IOWA.

.DAY ONE...TONIGHT

THERE IS A MODERATE RISK OF SEVERE WEATHER FROM 600 PM TONIGHT
THROUGH THE REST OF THE NIGHT.  THREATS INCLUDE VERY LARGE HAIL AND
DAMAGING STRAIGHT LINE WINDS.  CONDITIONS ARE ALSO FAVORABLE FOR
STRONG TORNADOES.  EVENING HOURS. ISOLATED FLASH FLOODING CANNOT BE
RULED OUT...BUT IS NOT LIKELY.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SEVERE THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON AND AGAIN
MONDAY AFTERNOON AND NIGHT.

.SPOTTER ACTIVATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TONIGHT. SPOTTER ACTIVATION MAY ALSO
BE NEEDED AGAIN ON SUNDAY AFTERNOON AND MONDAY.

IAZ070>072-081>083-231100-
ADAIR-ADAMS-CASS-CLARKE-MADISON-UNION-
327 PM CDT SAT MAY 22 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR A PORTION OF SOUTHERN IOWA.

.DAY ONE...TONIGHT

THERE IS A MODERATE RISK OF SEVERE WEATHER FROM 600 PM THIS
EVENING THROUGH THE REST OF THE NIGHT.  THREATS INCLUDE VERY LARGE
HAIL AND DAMAGING STRAIGHT LINE WINDS. CONDITIONS ARE ALSO VERY
FAVORABLE FOR STRONG TORNADOES DURING THE EVENING. ISOLATED FLASH
FLOODING CANNOT BE RULED OUT...BUT IS NOT LIKELY.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SEVERE WEATHER IS POSSIBLE MONDAY AFTERNOON AND NIGHT.

.SPOTTER ACTIVATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED TONIGHT. SPOTTER ACTIVATION
MAY ALSO BE NEEDED MONDAY AFTERNOON AND NIGHT.

In the hours before

Local storm report, May 22, 11:56 PM CDT, 39 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
1156 PM CDT SAT MAY 22 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

1137 PM     TSTM WND GST     7 W MOUNT AYR           40.71N 94.37W
05/22/2004  75 MPH           RINGGOLD           IA   TRAINED SPOTTER

1139 PM     TSTM WND DMG     2 N LENOX               40.91N 94.56W
05/22/2004                   ADAMS              IA   EMERGENCY MNGR

            POWER LINES DOWN. BUILDING AND BARN DAMAGE.

1145 PM     TSTM WND GST     3 W ST. CHARLES         41.29N 93.86W
05/22/2004  106 MPH          MADISON            IA   TRAINED SPOTTER

            MEASURED WINDSPEED.

&&

SS

Local storm report, May 23, 12:17 AM CDT, 18 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
1217 AM CDT SUN MAY 23 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

1133 PM     TORNADO          ADAIR                   41.50N 94.64W
05/22/2004                   ADAIR              IA   LAW ENFORCEMENT

            TORNADO SITED HIGHWAY 25 AND 320TH STREET IN ADAIR

&&

REESE

Local storm report, May 23, 12:20 AM CDT, 15 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
1220 AM CDT SUN MAY 23 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

1202 AM     TSTM WND DMG     BEVINGTON               41.36N 93.79W
05/23/2004                   WARREN             IA   FIRE DEPT/RESCUE

            LARGE TREES DOWN AND PERSONAL INJURIES IN BEVINGTON AND
            MARTINSDALE

&&

REESE

Local storm report, May 23, 12:24 AM CDT, 11 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
1224 AM CDT SUN MAY 23 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

1030 PM     TORNADO          3 W LEWIS               41.31N 95.14W
05/22/2004                   CASS               IA   EMERGENCY MNGR

            TORNADO CONFIRMED 3 MI WEST OF LEWIS, HGHWAY 71. TWO
            FARMSTEAD HOMES, ONE LOST WINDOWS, THE OTHER OVERWHELMING
            LOSS.

&&

REESE

Local storm report, May 23, 12:28 AM CDT, 7 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
1228 AM CDT SUN MAY 23 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

1215 AM     TSTM WND DMG     MASSENA                 41.25N 94.77W
05/23/2004                   CASS               IA   TRAINED SPOTTER

            LARGE 3 FOOT TREES DOWN.

&&

REESE

Local storm report, May 23, 12:29 AM CDT, 6 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
1229 AM CDT SUN MAY 23 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

1150 PM     TSTM WND GST     2 N CUMMING             41.51N 93.76W
05/22/2004  65 MPH           POLK               IA   BROADCAST MEDIA

1201 AM     TORNADO          1 ENE SPRING HILL       41.42N 93.63W
05/23/2004                   WARREN             IA   AMATEUR RADIO

&&

JAW

The office that day

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

Issued	Product	Office	Counties	Lasted
May 22, 7:00 PM CDT	Tornado Warning	DMX	Adair	30 min
May 22, 7:01 PM CDT	Tornado Warning	DMX	Adair	29 min
May 22, 7:04 PM CDT	Severe Thunderstorm Warning	DMX	Audubon	26 min
May 22, 7:06 PM CDT	Tornado Warning	DMX	Polk, Story	54 min
May 22, 7:10 PM CDT	Tornado Warning	DMX	Dallas, Guthrie	50 min
May 22, 7:13 PM CDT	Flash Flood Warning	DMX	Boone, Story	92 min
May 22, 7:14 PM CDT	Tornado Warning	DMX	Audubon	31 min
May 22, 7:14 PM CDT	Tornado Warning	DMX	Greene, Guthrie	46 min
May 22, 7:23 PM CDT	Tornado Warning	DMX	Madison	37 min
May 22, 7:31 PM CDT	Tornado Warning	DMX	Guthrie	44 min
May 22, 7:49 PM CDT	Tornado Warning	DMX	Jasper, Marshall	56 min
May 22, 7:51 PM CDT	Tornado Warning	DMX	Dallas	39 min
May 22, 7:57 PM CDT	Tornado Warning	DMX	Story	33 min
May 22, 8:18 PM CDT	Tornado Warning	DMX	Polk	57 min
May 22, 8:21 PM CDT	Flash Flood Warning	DMX	Audubon, Boone, Carroll, Dallas, Greene, Guthrie and 4 more	16 hr
May 22, 8:29 PM CDT	Tornado Warning	DMX	Dallas	16 min
May 22, 8:31 PM CDT	Severe Thunderstorm Warning	DMX	Dallas, Guthrie	44 min
May 22, 8:41 PM CDT	Tornado Warning	DMX	Tama	49 min
May 22, 8:43 PM CDT	Tornado Warning	DMX	Marshall	47 min
May 22, 9:09 PM CDT	Tornado Warning	DMX	Polk, Story	36 min
May 22, 9:14 PM CDT	Tornado Warning	DMX	Dallas	31 min
May 22, 9:16 PM CDT	Severe Thunderstorm Warning	DMX	Audubon	44 min
May 22, 9:27 PM CDT	Tornado Warning	DMX	Marshall, Tama	63 min
May 22, 9:31 PM CDT	Flash Flood Warning	DMX	Tama	15 hr
May 22, 10:00 PM CDT	Severe Thunderstorm Warning	DMX	Cass	45 min
May 22, 10:14 PM CDT	Severe Thunderstorm Warning	DMX	Black Hawk	46 min
May 22, 10:22 PM CDT	Flash Flood Warning	DMX	Black Hawk	16 hr
May 22, 10:23 PM CDT	Severe Thunderstorm Warning	DMX	Polk, Story	52 min
May 22, 10:24 PM CDT	Severe Thunderstorm Warning	DMX	Adair	36 min
May 22, 10:46 PM CDT	Severe Thunderstorm Warning	DMX	Cass	29 min
May 22, 10:48 PM CDT	Severe Thunderstorm Warning	DMX	Adams, Taylor	57 min
May 22, 10:55 PM CDT	Severe Thunderstorm Warning	DMX	Guthrie	50 min
May 22, 10:57 PM CDT	Severe Thunderstorm Warning	DMX	Adair	48 min
May 22, 11:09 PM CDT	Severe Thunderstorm Warning	DMX	Madison, Ringgold, Union	51 min
May 22, 11:20 PM CDT	Severe Thunderstorm Warning	DMX	Dallas	55 min
May 22, 11:31 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Decatur	44 min
May 22, 11:36 PM CDT	Severe Thunderstorm Warning	DMX	Polk, Warren	54 min
May 22, 11:54 PM CDT	Tornado Warning	DMX	Warren	36 min
May 23, 12:07 AM CDT	Tornado Warning	DMX	Jasper, Marion	53 min
May 23, 12:22 AM CDT	Severe Thunderstorm Warning	DMX	Lucas	23 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2004 Every severe thunderstorm warning in 2004

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.