Alert archive / Iowa / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 13, NWS Des Moines, IA

March 21, 2007Palo Alto County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Mar 21, 2007, 6:47 PM CDT for Palo Alto County, Iowa. It was in force for 27 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: Mar 21, 2007, 6:47 PM CDT (23:47 UTC)
Expired: Mar 21, 2007, 7:14 PM CDT
In force: 27 min
Issued by: NWS Des Moines, IA
Area: Counties, with a storm outline in the text

County Palo Alto County, IA

The radar

The Sioux Falls radar (KFSD), 171 km from the middle of the area, began a volume at 23:47 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.

Issued	Product	Office	Lasted
Mar 21, 5:15 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 11.8 hours before the alert went out and 208 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: 529 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 338 m²/s²
0-3 km storm-relative helicity: 323 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 
WUUS53 KDMX 212347
SVRDMX
IAC147-220030-
/O.NEW.KDMX.SV.W.0013.070321T2347Z-070322T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
647 PM CDT WED MAR 21 2007

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN PALO ALTO COUNTY IN NORTHWEST IOWA...

* UNTIL 730 PM CDT

* AT 645 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  EMMETSBURG...OR 25 MILES EAST OF SPENCER...AND MOVING EAST AT 40
  MPH.

* THE SEVERE THUNDERSTORM WILL AFFECT MAINLY RURAL AREAS OF NORTHERN
  PALO ALTO COUNTY...INCLUDING THE TOWNS OF EMMETSBURG AND CYLINDER.

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

LAT...LON 4325 9483 4302 9488 4300 9446 4326 9446

$$

VACHALEK

1 follow-up statement

000 
WWUS53 KDMX 220014
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
714 PM CDT WED MAR 21 2007

IAC147-220024-
/O.CAN.KDMX.SV.W.0013.000000T0000Z-070322T0030Z/
PALO ALTO IA-
714 PM CDT WED MAR 21 2007

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN PALO ALTO COUNTY HAS
BEEN CANCELLED...

AT 712 PM CDT...WEATHER SERVICE DOPPLER RADAR INDICATED THAT THE 
THUNDERSTORMS WHICH PROMPTED THE WARNING HAVE MOVED OUT OF THE 
AREA...AND NO LONGER POSE AN IMMEDIATE THREAT TO LIFE OR PROPERTY. 
THEREFORE...THE SEVERE THUNDERSTORM WARNING HAS BEEN CANCELLED.

IF SEVERE WEATHER OCCURRED IN YOUR AREA...PLEASE REPORT IT TO LOCAL 
LAW ENFORCEMENT FOR RELAY TO THE NATIONAL WEATHER SERVICE.

LAT...LON 4325 9483 4302 9488 4300 9446 4326 9446

$$

VACHALEK

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 21, 7:11 AM CDT	Severe Thunderstorm Warning	DMX	Cass	23 min
Mar 21, 8:34 AM CDT	Severe Thunderstorm Warning	DMX	Madison	29 min
Mar 21, 8:48 AM CDT	Severe Thunderstorm Warning	DMX	Dallas	42 min
Mar 21, 9:06 AM CDT	Severe Thunderstorm Warning	DMX	Polk	54 min
Mar 21, 9:58 AM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marshall, Story	47 min
Mar 21, 10:03 AM CDT	Severe Thunderstorm Warning	DMX	Dallas, Polk	57 min
Mar 21, 10:44 AM CDT	Severe Thunderstorm Warning	DMX	Story	46 min
Mar 21, 11:46 AM CDT	Severe Thunderstorm Warning	DMX	Marshall	29 min
Mar 21, 11:54 AM CDT	Severe Thunderstorm Warning	DMX	Wapello	36 min
Mar 21, 6:00 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	60 min
Mar 21, 6:27 PM CDT	Severe Thunderstorm Warning	DMX	Emmet, Kossuth	63 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2007 Every severe thunderstorm warning 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.