Alert archive / Iowa / Tornado Warnings in 2007

Tornado Warning 35, NWS Des Moines, IA

August 21, 2007Humboldt County, Pocahontas County, Iowa

NWS Des Moines, IA issued this tornado warning at Aug 21, 2007, 7:49 PM CDT for Humboldt County, Pocahontas County, Iowa. It was in force for 41 min. 5 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 21, 2007, 7:49 PM CDT (00:49 UTC)
Expired: Aug 21, 2007, 8:30 PM CDT
In force: 41 min
Issued by: NWS Des Moines, IA
Area: Counties, with a storm outline in the text

Counties Humboldt County, IA, Pocahontas County, IA

The radar

The Des Moines radar (KDMX), 143 km from the middle of the area, began a volume at 00:50 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.

What was reported inside it

Time	Report	Where	Remark
Aug 21, 7:58 PM CDT	TSTM WND GST 70	1 N Plover, IA	HEAVY RAIN
Aug 21, 8:02 PM CDT	TSTM WND DMG	Rolfe, IA	POWER POLES DOWN AND TREES DOWN BETWEEN ROLFE AND PLOVER
Aug 21, 8:02 PM CDT	TSTM WND GST 70	1 N Rolfe, IA	60 TO 70 MPH ESTIMATED WINDS AND HEAVY RAIN
Aug 21, 8:02 PM CDT	TSTM WND GST 80	5 N Rolfe, IA	TREES DOWN
Aug 21, 8:07 PM CDT	TSTM WND DMG	3 N Bradgate, IA	OUTBUILDINGS, GRAIN BINS, TREES DOWN.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

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

Issued	Product	Office	Lasted
Aug 21, 6:47 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 0.8 hours before the alert went out and 231 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: 1298 m above ground
0-6 km bulk shear: 65 kt
0-1 km storm-relative helicity: 8 m²/s²
0-3 km storm-relative helicity: 453 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 
WFUS53 KDMX 220048
TORDMX
IAC091-151-220130-
/O.NEW.KDMX.TO.W.0035.070822T0049Z-070822T0130Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
749 PM CDT TUE AUG 21 2007

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHWESTERN HUMBOLDT COUNTY IN NORTH CENTRAL IOWA...
  NORTHEASTERN POCAHONTAS COUNTY IN NORTHWEST IOWA...

* UNTIL 830 PM CDT.

* AT 746 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR PLOVER...OR
  ABOUT 33 MILES SOUTHEAST OF SPENCER...MOVING EAST AT 25 MPH.

* THE TORNADO WILL BE NEAR...
  ROLFE BY 755 PM CDT...
  BRADGATE BY 805 PM CDT...
  OTTOSEN BY 810 PM CDT...

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.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 200 AM CDT WEDNESDAY MORNING
FOR NORTHWESTERN IOWA.

LAT...LON 4291 9470 4292 9448 4292 9447 4292 9431
      4291 9431 4274 9435 4280 9474
TIME...MOT...LOC 0049Z 280DEG 25KT 4287 9459

$$

KINNEY

2 follow-up statements

000 
WWUS53 KDMX 220101
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
800 PM CDT TUE AUG 21 2007

IAC091-151-220130-
/O.CON.KDMX.TO.W.0035.000000T0000Z-070822T0130Z/
POCAHONTAS IA-HUMBOLDT IA-
800 PM CDT TUE AUG 21 2007

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 830 PM CDT FOR
NORTHWESTERN HUMBOLDT AND NORTHEASTERN POCAHONTAS COUNTIES...

AT 758 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO.  THIS TORNADO WAS LOCATED NEAR ROLFE...OR ABOUT
29 MILES NORTHWEST OF FORT DODGE...MOVING EAST AT 25 MPH.

THE TORNADO WILL BE NEAR...
  BRADGATE AND OTTOSEN BY 810 PM CDT...

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.

IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING 
DESTRUCTIVE STRAIGHT LINE WINDS OF 70 MPH. AT 759 PM...LAW 
ENFORCEMENT SPOTTERS REPORTED 70 MPH JUST NORTHEAST OF PLOVER.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 200 AM CDT WEDNESDAY MORNING
FOR NORTHWESTERN IOWA.

THIS IS A DANGEROUS STORM. TAKE SHELTER IMMEDIATELY.

LAT...LON 4291 9470 4292 9448 4292 9447 4292 9431
      4291 9431 4274 9435 4280 9474
TIME...MOT...LOC 0100Z 280DEG 25KT 4286 9449

$$

JUNGBLUTH

000 
WWUS53 KDMX 220133
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
831 PM CDT TUE AUG 21 2007

IAC091-151-220145-
/O.EXP.KDMX.TO.W.0035.000000T0000Z-070822T0130Z/
POCAHONTAS IA-HUMBOLDT IA-
831 PM CDT TUE AUG 21 2007

...THE TORNADO WARNING FOR NORTHEASTERN POCAHONTAS COUNTY EXPIRES 
AT 830 PM CDT...

...THE TORNADO WARNING FOR NORTHWEST HUMBOLDT COUNTY HAS BEEN 
REPLACED BY A SEVERE THUNDERSTORM WARNING...

AT 828 PM CDT...WEATHER SERVICE DOPPLER RADAR INDICATED THAT THE
THUNDERSTORMS WHICH PROMPTED THE WARNING HAVE MOVED OUT OF THE AREA.
THEREFORE...THE TORNADO WARNING HAS BEEN ALLOWED TO EXPIRE.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 200 AM CDT WEDNESDAY MORNING
FOR NORTHERN IOWA.

LAT...LON 4291 9470 4292 9448 4292 9447 4292 9431
      4291 9431 4274 9435 4280 9474
TIME...MOT...LOC 0101Z 280DEG 25KT 4286 9448

$$

KINNEY

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 21, 7:16 PM CDT	Severe Thunderstorm Warning	DMX	Palo Alto	59 min
Aug 21, 7:40 PM CDT	Flash Flood Warning	DMX	Palo Alto	6 hr
Aug 21, 8:04 PM CDT	Severe Thunderstorm Warning	DMX	Kossuth	56 min
Aug 21, 8:07 PM CDT	Severe Thunderstorm Warning	DMX	Humboldt	53 min
Aug 21, 8:24 PM CDT	Flash Flood Warning	DMX	Winnebago, Worth	6 hr
Aug 21, 8:24 PM CDT	Severe Thunderstorm Warning	DMX	Humboldt, Pocahontas, Webster	66 min
Aug 21, 8:29 PM CDT	Severe Thunderstorm Warning	DMX	Humboldt	46 min
Aug 21, 8:33 PM CDT	Flash Flood Warning	DMX	Franklin, Humboldt, Wright	6 hr
Aug 21, 8:33 PM CDT	Flash Flood Warning	DMX	Franklin, Humboldt, Pocahontas, Wright	6 hr
Aug 21, 8:55 PM CDT	Severe Thunderstorm Warning	DMX	Hamilton, Wright	65 min
Aug 21, 9:42 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo	38 min
Aug 21, 10:00 PM CDT	Severe Thunderstorm Warning	DMX	Butler	60 min
Aug 21, 10:06 PM CDT	Flash Flood Warning	DMX	Webster	6 hr
Aug 21, 10:13 PM CDT	Flash Flood Warning	DMX	Bremer, Butler	6 hr
Aug 21, 10:13 PM CDT	Severe Thunderstorm Warning	DMX	Sac	47 min
Aug 21, 10:21 PM CDT	River Flood Warning	DMX	Humboldt	5 days
Aug 21, 10:21 PM CDT	River Flood Warning	DMX	Cerro Gordo, Floyd, Worth	42 hr
Aug 21, 11:07 PM CDT	Flash Flood Warning	DMX	Webster	6 hr
Aug 21, 11:16 PM CDT	Flash Flood Warning	DMX	Grundy, Hardin	6 hr
Aug 21, 11:17 PM CDT	Flash Flood Warning	DMX	Grundy, Hamilton, Hardin	6 hr
Aug 21, 11:32 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	28 min
Aug 22, 3:20 AM CDT	River Flood Warning	DMX	Webster	66 hr
Aug 22, 5:55 AM CDT	River Flood Warning	DMX	Black Hawk	4 days
Aug 22, 5:55 AM CDT	River Flood Warning	DMX	Black Hawk	4 days
Aug 22, 9:57 AM CDT	Severe Thunderstorm Warning	DMX	Sac	48 min
Aug 22, 11:33 AM CDT	Flash Flood Warning	DMX	Calhoun, Sac	6 hr

Nearby

Tornado Warnings in Iowa, 2007 Every tornado warning in 2007 Tornadoes in 2007

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.