Alert archive / Iowa / Tornado Warnings in 2009

Tornado Warning 3, NWS Des Moines, IA

April 26, 2009Black Hawk County, Tama County, Iowa

NWS Des Moines, IA issued this tornado warning at Apr 26, 2009, 6:08 PM CDT for Black Hawk County, Tama County, Iowa. It was in force for 37 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
Apr 26, 2009, 6:08 PM CDT (23:08 UTC)
Expired
Apr 26, 2009, 6:45 PM CDT
In force
37 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon

Counties Black Hawk County, IA, Tama County, IA

The radar

The Des Moines radar (KDMX), 142 km from the middle of the area, began a volume at 23:08 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 watch it was issued in

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

IssuedProductOfficeLasted
Apr 26, 5:02 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.1 hours before the alert went out and 165 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 12:00Z on 2009-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2009-04-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 402 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
586 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
402 m²/s²
0-3 km storm-relative helicity
403 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KDMX 262308
TORDMX
IAC013-171-262345-
/O.NEW.KDMX.TO.W.0003.090426T2308Z-090426T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
608 PM CDT SUN APR 26 2009

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  EASTERN BLACK HAWK COUNTY IN NORTHEAST IOWA...
  NORTHEASTERN TAMA COUNTY IN CENTRAL IOWA...

* UNTIL 645 PM CDT

* AT 607 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED 6 MILES NORTHWEST OF DYSART...OR 20 MILES WEST OF
  VINTON...AND MOVING NORTHEAST AT 40 MPH.

* THIS TORNADIC STORM WILL BE NEAR...
  LA PORTE CITY BY 625 PM CDT...
  GILBERTVILLE BY 630 PM CDT...
  RAYMOND...ELK RUN HEIGHTS AND EVANSDALE BY 635 PM CDT...
  DUNKERTON BY 645 PM CDT...

THIS INCLUDES INTERSTATE 380 BETWEEN MILE MARKERS 58 AND 73.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A HAZARDOUS SITUATION. SEEK SHELTER IN A BASEMENT...OR IN AN
INTERIOR ROOM. STAY AWAY FROM WINDOWS. IF YOU ARE OUTSIDE OR IN A
CAR...SEEK SHELTER IN A REINFORCED BUILDING.

&&

LAT...LON 4229 9221 4229 9229 4228 9230 4222 9230
      4217 9237 4222 9248 4262 9229 4255 9208
      4248 9208 4247 9206 4239 9206
TIME...MOT...LOC 2308Z 212DEG 37KT 4222 9240

$$

SMALL
3 follow-up statements
000 
WWUS53 KDMX 262320
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
620 PM CDT SUN APR 26 2009

IAC171-262330-
/O.CAN.KDMX.TO.W.0003.000000T0000Z-090426T2345Z/
TAMA IA-
620 PM CDT SUN APR 26 2009

...THE TORNADO WARNING FOR NORTHEASTERN TAMA COUNTY IS CANCELLED...

LAT...LON 4241 9212 4233 9224 4229 9229 4233 9242
      4262 9229 4255 9208 4248 9208 4247 9206
TIME...MOT...LOC 2320Z 209DEG 36KT 4237 9231

$$

IAC013-262345-
/O.CON.KDMX.TO.W.0003.000000T0000Z-090426T2345Z/
BLACK HAWK IA-
620 PM CDT SUN APR 26 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM CDT FOR EASTERN
BLACK HAWK COUNTY...

AT 618 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO. THIS TORNADO WAS LOCATED 7 MILES SOUTHWEST OF
GILBERTVILLE...OR 10 MILES SOUTH OF WATERLOO...MOVING NORTHEAST AT 40
MPH.

THE TORNADO WILL BE NEAR...
  GILBERTVILLE BY 625 PM CDT...
  ELK RUN HEIGHTS...RAYMOND AND EVANSDALE BY 630 PM CDT...
  DUNKERTON BY 640 PM CDT...

THIS INCLUDES INTERSTATE 380 BETWEEN MILE MARKERS 61 AND 73.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEEK SHELTER IN A BASEMENT...OR IN AN INTERIOR ROOM. STAY AWAY FROM
WINDOWS. IF YOU ARE IN A CAR OR OUTSIDE...SEEK SHELTER IN A
REINFORCED BUILDING.

&&

LAT...LON 4241 9212 4233 9224 4229 9229 4233 9242
      4262 9229 4255 9208 4248 9208 4247 9206
TIME...MOT...LOC 2320Z 209DEG 36KT 4237 9231

$$

DONAVON
000 
WWUS53 KDMX 262334
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
634 PM CDT SUN APR 26 2009

IAC013-262345-
/O.CON.KDMX.TO.W.0003.000000T0000Z-090426T2345Z/
BLACK HAWK IA-
634 PM CDT SUN APR 26 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM CDT FOR EASTERN
BLACK HAWK COUNTY...

AT 634 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO. THIS TORNADO WAS LOCATED NEAR RAYMOND...OR 6
MILES EAST OF WATERLOO...MOVING NORTHEAST AT 35 MPH.

THE TORNADO WILL BE NEAR...
  EVANSDALE BY 635 PM CDT...
  DUNKERTON BY 645 PM CDT...

THIS INCLUDES INTERSTATE 380 BETWEEN MILE MARKERS 63 AND 73.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEEK SHELTER IN A BASEMENT...OR IN AN INTERIOR ROOM. STAY AWAY FROM
WINDOWS. IF YOU ARE IN A CAR OR OUTSIDE...SEEK SHELTER IN A
REINFORCED BUILDING.

&&

LAT...LON 4255 9208 4248 9209 4246 9211 4235 9223
      4242 9238 4262 9229
TIME...MOT...LOC 2334Z 214DEG 30KT 4246 9223

$$

DONAVON
000 
WWUS53 KDMX 262346
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
646 PM CDT SUN APR 26 2009

IAC013-262355-
/O.EXP.KDMX.TO.W.0003.000000T0000Z-090426T2345Z/
BLACK HAWK IA-
646 PM CDT SUN APR 26 2009

...THE TORNADO WARNING FOR EASTERN BLACK HAWK COUNTY EXPIRES AT 645
PM CDT...

THIS INCLUDES INTERSTATE 380 BETWEEN MILE MARKERS 63 AND 73.

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED AND NO LONGER
APPEARED TO BE SEVERE.

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A TORNADO 
WATCH REMAINS IN EFFECT UNTIL MIDNIGHT.

LAT...LON 4255 9208 4248 9209 4246 9211 4235 9223
      4242 9238 4262 9229
TIME...MOT...LOC 2334Z 214DEG 30KT 4246 9223

$$

DONAVON

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 25, 7:28 PM CDTSevere Thunderstorm WarningDMXDallas, Madison, Warren24 min
Apr 25, 9:02 PM CDTRiver Flood WarningDMXDecatur48 hr
Apr 25, 9:02 PM CDTRiver Flood WarningDMXLucas, Wayne5 days
Apr 25, 9:02 PM CDTRiver Flood WarningDMXAppanoose, Wayne55 hr
Apr 25, 9:19 PM CDTAreal Flood AdvisoryDMXAppanoose, Davis, Wapello6 hr
Apr 26, 3:38 AM CDTFlash Flood WatchDMXAdair, Adams, Appanoose, Audubon, Black Hawk, Boone and 34 more24 hr
Apr 26, 7:10 AM CDTRiver Flood WarningDMXTaylor24 hr
Apr 26, 10:40 AM CDTSevere Thunderstorm WarningDMXAdair, Adams, Madison, Union32 min
Apr 26, 1:15 PM CDTRiver Flood WarningDMXPolk, Story27 hr
Apr 26, 1:24 PM CDTRiver Flood WarningDMXMadison, Warren48 hr
Apr 26, 2:09 PM CDTSevere Thunderstorm WarningDMXCass51 min
Apr 26, 3:19 PM CDTRiver Flood WarningDMXMadison, Warren4 days
Apr 26, 3:42 PM CDTSevere Thunderstorm WarningDMXAudubon, Cass48 min
Apr 26, 3:51 PM CDTAreal Flood AdvisoryDMXBlack Hawk, Grundy, Marshall, Tama3 hr
Apr 26, 3:51 PM CDTRiver Flood WarningDMXStory20 hr
Apr 26, 4:08 PM CDTFlash Flood WarningDMXBlack Hawk6 hr
Apr 26, 4:08 PM CDTRiver Flood WarningDMXWarren19 hr
Apr 26, 4:40 PM CDTFlash Flood WarningDMXAdair, Audubon, Cass, Guthrie6 hr
Apr 26, 4:58 PM CDTSevere Thunderstorm WarningDMXAdair, Audubon, Cass, Guthrie47 min
Apr 26, 5:17 PM CDTAreal Flood AdvisoryDMXDallas, Madison, Polk, Warren3 hr
Apr 26, 6:04 PM CDTSevere Thunderstorm WarningDMXClarke, Decatur, Ringgold, Union41 min
Apr 26, 6:23 PM CDTSevere Thunderstorm WarningDMXJasper, Marshall, Poweshiek, Tama37 min
Apr 26, 6:29 PM CDTFlash Flood WarningDMXMarshall6 hr
Apr 26, 6:36 PM CDTSevere Thunderstorm WarningDMXClarke, Decatur, Lucas, Marion, Warren39 min
Apr 26, 6:39 PM CDTSevere Thunderstorm WarningDMXMarion, Polk, Warren51 min
Apr 26, 6:50 PM CDTSevere Thunderstorm WarningDMXAppanoose, Decatur, Lucas, Monroe, Wayne40 min
Apr 26, 6:56 PM CDTSevere Thunderstorm WarningDMXTama26 min
Apr 26, 6:58 PM CDTSevere Thunderstorm WarningDMXMarion47 min
Apr 26, 6:59 PM CDTFlash Flood WarningDMXGrundy, Marshall, Tama6 hr

Nearby

Tornado Warnings in Iowa, 2009Every tornado warning in 2009Tornadoes in 2009

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.