Alert archive / Iowa / Tornado Warnings in 2011

Tornado Warning 5, NWS Omaha, NE

March 22, 2011Montgomery County, Iowa

NWS Omaha, NE issued this tornado warning at Mar 22, 2011, 5:08 PM CDT for Montgomery County, Iowa. It was in force for 22 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 22, 2011, 5:08 PM CDT (22:08 UTC)
Expired: Mar 22, 2011, 5:30 PM CDT
In force: 22 min
Issued by: NWS Omaha, NE
Area: Storm-based polygon

County Montgomery County, IA

The radar

The Omaha radar (KOAX), 115 km from the middle of the area, began a volume at 22:09 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 22, 2:03 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 10.1 hours before the alert went out and 115 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: 486 J/kg
Mixed-layer CIN: -475 J/kg
Mixed-layer LCL: 777 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 477 m²/s²
0-3 km storm-relative helicity: 501 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.

274 
WFUS53 KOAX 222208
TOROAX
IAC137-222245-
/O.NEW.KOAX.TO.W.0005.110322T2208Z-110322T2245Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
508 PM CDT TUE MAR 22 2011

THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHEASTERN MONTGOMERY COUNTY IN SOUTHWEST IOWA...

* UNTIL 545 PM CDT

* AT 504 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED 5 MILES SOUTHEAST OF ELLIOTT...OR 48 MILES NORTH
  OF TARKIO...AND MOVING NORTHEAST AT 55 MPH.

* LOCATIONS IMPACTED INCLUDE...
  GRANT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4103 9511 4116 9515 4116 9493 4116 9492
      4107 9493
TIME...MOT...LOC 2208Z 237DEG 49KT 4113 9502

$$

MAYES

1 follow-up statement

762 
WWUS53 KOAX 222230
SVSOAX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
530 PM CDT TUE MAR 22 2011

IAC137-222240-
/O.CAN.KOAX.TO.W.0005.000000T0000Z-110322T2245Z/
MONTGOMERY IA-
530 PM CDT TUE MAR 22 2011

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

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED
AREA.

LAT...LON 4103 9511 4116 9515 4116 9493 4116 9492
      4107 9493
TIME...MOT...LOC 2230Z 237DEG 49KT 4129 9468

$$

MAYES

The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 22, 4:10 PM CDT	Severe Thunderstorm Warning	OAX	Fremont, Mills	50 min
Mar 22, 4:48 PM CDT	Severe Thunderstorm Warning	OAX	Harrison	42 min
Mar 22, 4:53 PM CDT	Tornado Warning	OAX	Harrison	37 min
Mar 22, 4:57 PM CDT	Severe Thunderstorm Warning	OAX	Montgomery, Pottawattamie	33 min
Mar 22, 5:03 PM CDT	Tornado Warning	OAX	Harrison, Pottawattamie	27 min
Mar 22, 5:19 PM CDT	Tornado Warning	OAX	Shelby	26 min
Mar 22, 5:31 PM CDT	Tornado Warning	OAX	Harrison, Shelby	29 min

Nearby

Tornado Warnings in Iowa, 2011 Every tornado warning in 2011 Tornadoes in 2011

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.