Alert archive / Iowa / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 2, NWS Sioux Falls, SD

March 21, 2007Buena Vista County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Mar 21, 2007, 6:56 PM CDT for Buena Vista County, Iowa. It was in force for 19 min. 1 report 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
Mar 21, 2007, 6:56 PM CDT (23:56 UTC)
Expired
Mar 21, 2007, 7:15 PM CDT
In force
19 min
Issued by
NWS Sioux Falls, SD
Area
Counties, with a storm outline in the text

County Buena Vista County, IA

The radar

The Des Moines radar (KDMX), 157 km from the middle of the area, began a volume at 23:59 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.

What was reported inside it

TimeReportWhereRemark
Mar 21, 7:00 PM CDTHAIL 17 Se Sioux Rapids, IAPUBLIC REPORT

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.

IssuedProductOfficeLasted
Mar 21, 5:15 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 11.9 hours before the alert went out and 193 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, Omaha, NE at 12:00Z on 2007-03-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 316 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 12:00Z on 2007-03-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 284 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
316 J/kg
Mixed-layer CIN
-260 J/kg
Mixed-layer LCL
503 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
284 m²/s²
0-3 km storm-relative helicity
321 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.2

Open this sounding in Storm Lab

The text

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

000 
WUUS53 KFSD 212357
SVRFSD
IAC021-220015-
/O.NEW.KFSD.SV.W.0002.070321T2356Z-070322T0015Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
656 PM CDT WED MAR 21 2007

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN BUENA VISTA COUNTY IN NORTHWEST IOWA

* UNTIL 715 PM CDT

* AT 656 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL.  THIS
  STORM WAS LOCATED 6 MILES SOUTHWEST OF MARATHON...OR ABOUT 13 MILES
  NORTHEAST OF STORM LAKE...MOVING EAST AT 25 MPH.  ANOTHER RAPIDLY
  DEVELOPING STORM WAS LOCATED 5 MILES WEST OF NEWELL...MOVING EAST
  AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  MARATHON AROUND 700 PM CDT...
  NEWELL AROUND 705 PM CDT...

THIS EXTENDS THE PREVIOUS WARNING FOR BUENA VISTA COUNTY.  AT 650 PM 
CDT...NICKEL SIZE HAIL WAS REPORTED 1 MILE SOUTHEAST OF REMBRANDT BY 
THE PUBLIC.

THIS STORM HAS A HISTORY OF PRODUCING LARGE HAIL. GO INSIDE A STURDY
BUILDING AND STAY AWAY FROM WINDOWS.

LAT...LON 4285 9512 4256 9513 4256 9492 4291 9493

$$

CHAPMAN
1 follow-up statement
000 
WWUS53 KFSD 220015
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
715 PM CDT WED MAR 21 2007

IAC021-220024-
/O.EXP.KFSD.SV.W.0002.000000T0000Z-070322T0015Z/
BUENA VISTA IA-
715 PM CDT WED MAR 21 2007

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN BUENA VISTA COUNTY
EXPIRES AT 715 PM CDT...

THE THUNDERSTORM EAST OF MARATHON HAS WEAKENED AND EXITED THE 
COUNTY...AND WAS NO LONGER SEVERE. A SECOND STORM WAS LOCATED
ABOUT 5 MILES EAST OF NEWELL...WITH SMALL HAIL STILL POSSIBLE 
THROUGH 730 PM CDT IN FAR SOUTHEASTERN PORTIONS OF BUENA VISTA 
COUNTY.

LAT...LON 4285 9512 4256 9513 4256 9492 4291 9493

$$

CHAPMAN

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 21, 6:31 PM CDTSevere Thunderstorm WarningFSDBuena Vista29 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2007Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.