Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 42, NWS Omaha, NE

April 14, 2012Cass County, Nebraska; Fremont County, Mills County, Iowa

NWS Omaha, NE issued this severe thunderstorm warning at Apr 14, 2012, 5:35 PM CDT for Cass County, Nebraska; Fremont County, Mills County, Iowa. It was in force for 25 min. 2 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: Apr 14, 2012, 5:35 PM CDT (22:35 UTC)
Expired: Apr 14, 2012, 6:00 PM CDT
In force: 25 min
Issued by: NWS Omaha, NE
Area: Storm-based polygon
Hail: 0.75 in
Wind: 70.0 mph

Counties Fremont County, IA, Mills County, IA, Cass County, NE

The radar

The Omaha radar (KOAX), 68 km from the middle of the area, began a volume at 22:35 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
Apr 14, 5:35 PM CDT	TORNADO	Thurman, IA	75 PERCENT OF THE TOWN OF THURMAN WAS DESTROYED. THE TOWN HAS BEEN EVACUATED WITH AN EMERGENCY SHELTER IN A NEARBY TOWN. NO POWER IN THE TOWN. NO MAJOR INJURIES.
Apr 14, 5:54 PM CDT	TSTM WND GST 65	1 S Hastings, IA	MEASURED ON A HOME WEATHER STATION. TREE SNAPPED OFF JUST ABOVE GRADE AND MANY LIMBS SNAPPED AND THROWN.

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

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 3 storm reports to this severe thunderstorm warning; the first came 5 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

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

Issued	Product	Office	Lasted
Apr 14, 12:00 PM CDT	Tornado Watch PDS	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 10.6 hours before the alert went out and 69 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: 1847 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 2 m²/s²
0-3 km storm-relative helicity: 89 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.

330 
WUUS53 KOAX 142235
SVROAX
IAC071-129-NEC025-142300-
/O.NEW.KOAX.SV.W.0042.120414T2235Z-120414T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
535 PM CDT SAT APR 14 2012

THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EAST CENTRAL CASS COUNTY IN EASTERN NEBRASKA...
  NORTHWESTERN FREMONT COUNTY IN SOUTHWESTERN IOWA...
  MILLS COUNTY IN SOUTHWESTERN IOWA...

* UNTIL 600 PM CDT

* AT 531 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS 
  INDICATED A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING 
  DESTRUCTIVE WINDS IN EXCESS OF 70 MPH. THESE STORMS WERE LOCATED 
  ALONG A LINE EXTENDING FROM 16 MILES SOUTH OF PLATTSMOUTH TO 6 
  MILES EAST OF UNION...OR ALONG A LINE EXTENDING FROM 34 MILES 
  SOUTH OF OMAHA TO 54 MILES NORTHWEST OF MOUND CITY...AND MOVING 
  NORTHEAST AT 50 MPH. 

* LOCATIONS IMPACTED INCLUDE...
  PLATTSMOUTH...GLENWOOD...MALVERN...PACIFIC JUNCTION...TABOR...
  SILVER CITY...THURMAN...
  HASTINGS AND RANDOLPH. 

THIS INCLUDES INTERSTATE 29 BETWEEN MILE MARKERS 20 AND 35.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. ALTHOUGH 
NOT IMMEDIATELY LIKELY...IF A TORNADO IS SPOTTED...ACT QUICKLY AND 
MOVE TO A PLACE OF SAFETY IN A STURDY STRUCTURE...SUCH AS A 
BASEMENT OR SMALL INTERIOR ROOM.

&&

A TORNADO WATCH REMAINS IN EFFECT UNTIL 700 PM CDT SATURDAY 
EVENING FOR SOUTHWESTERN IOWA...NORTHWESTERN MISSOURI AND EASTERN 
NEBRASKA.

LAT...LON 4078 9584 4079 9586 4101 9594 4111 9583
      4115 9543 4091 9539
TIME...MOT...LOC 2231Z 236DEG 43KT 4100 9589 4078 9581 
WIND...HAIL 70MPH <.75IN

$$

BOUSTEAD/MAYES

2 follow-up statements

607 
WWUS53 KOAX 142248
SVSOAX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
548 PM CDT SAT APR 14 2012

IAC071-142310-
/O.CAN.KOAX.TO.W.0004.000000T0000Z-120414T2300Z/
FREMONT IA-
548 PM CDT SAT APR 14 2012

...THE TORNADO WARNING FOR NORTHWESTERN FREMONT COUNTY IS 
CANCELLED...

THE ROTATION WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE 
LIMITS...AND NO LONGER APPEARS CAPABLE OF PRODUCING A TORNADO. 
THEREFORE THE WARNING HAS BEEN CANCELLED. 

ADDITIONAL SEVERE THUNDERSTORM DEVELOPMENT REMAINS 
POSSIBLE...AND A TORNADO WATCH REMAINS IN EFFECT UNTIL 700 PM.

REMEMBER...A SEVERE THUNDERSTORM WARNING STILL REMAINS IN EFFECT 
FOR NORTHWEST FREMONT COUNTY UNTIL 600 PM...AND FOR THE REST OF 
FREMONT COUNTY UNTIL 615 PM.

LAT...LON 4081 9565 4076 9581 4079 9583 4086 9568
TIME...MOT...LOC 2246Z 246DEG 42KT 4080 9580 

$$

BOUSTEAD/MAYES

997 
WWUS53 KOAX 142301
SVSOAX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
601 PM CDT SAT APR 14 2012

IAC071-129-142310-
/O.EXP.KOAX.SV.W.0042.000000T0000Z-120414T2300Z/
MILLS IA-FREMONT IA-
601 PM CDT SAT APR 14 2012

...THE SEVERE THUNDERSTORM WARNING FOR MILLS AND EXTREME NORTH 
CENTRAL FREMONT COUNTIES HAS EXPIRED...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAVE MOVED OUT OF 
THE AREA. THEREFORE THE WARNING HAS BEEN ALLOWED TO EXPIRE.  A 
SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR MILLS COUNTY UNTIL 
630 PM.

ADDITIONAL SEVERE THUNDERSTORM DEVELOPMENT REMAINS POSSIBLE...AND 
A TORNADO WATCH REMAINS IN EFFECT UNTIL 700 PM.

LAT...LON 4091 9539 4083 9568 4102 9581 4111 9583
      4115 9543
TIME...MOT...LOC 2300Z 236DEG 43KT 4109 9571 4088 9558 

$$

BOUSTEAD/MAYES

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Omaha, NE wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 14, 2:55 PM CDT, 2 hours 40 minutes earlier.

Area forecast discussion, Apr 14, 2:55 PM CDT, 2 hours 40 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
255 PM CDT SAT APR 14 2012

.DISCUSSION...

SIGNIFICANT CONVECTIVE EVENT WILL CONTINUE THROUGH THE EVENING
ACROSS THE AREA WITH DRY SLOT WORKING IN AFTER MIDNIGHT AND
EXTENDING THROUGH SUNDAY MORNING. COLD FRONT MOVES THROUGH MOST OF
THE AREA SUNDAY AFTERNOON WITH SOME LINGERING SHOWERS MAINLY
OVER THE NORTHERN HALF OF THE FORECAST AREA SUNDAY AFTERNOON INTO
SUNDAY EVENING. GUSTY NORTHWEST WINDS ALSO LIKELY ON SUNDAY WITH
POTENTIAL FOR A WIND ADVISORY BUT WILL PASS TO LATER SHIFTS TO
HANDLE ANY ISSUANCE. NEXT UPPER WAVE COMING ACROSS THE CENTRAL
PLAINS LATE MONDAY INTO MONDAY NIGHT MAY TRIGGER SOME SHOWERS BUT
SPOTTY ENOUGH TO LIMIT MENTION AT THIS TIME.

LOAD AND GO TODAY WITH THE EXTENDED PERIOD WITH LITTLE CHANGE
TO PREVIOUS TRENDS.

&&

.AVIATION...
18Z TAFS FOR KOMA...KLNK AND KOFK.

PERIODS OF STRONG CONVECTION EXPECTED THROUGH 06Z WITH
DRY SLOT WORKING IN BETWEEN 06Z AND 12Z. STRONG SOUTH TO
SOUTHWEST FLOW SURFACE AND ALOFT WILL CONTINUE THROUGH THE PERIOD.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

FOBERT/MEYER

Hazardous weather outlook, Apr 14, 4:08 PM CDT, 1 hour 27 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
408 PM CDT SAT APR 14 2012

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-151115-
MONONA-HARRISON-SHELBY-POTTAWATTAMIE-MILLS-MONTGOMERY-FREMONT-
PAGE-KNOX-CEDAR-THURSTON-ANTELOPE-PIERCE-WAYNE-BOONE-MADISON-
STANTON-CUMING-BURT-PLATTE-COLFAX-DODGE-WASHINGTON-BUTLER-
SAUNDERS-DOUGLAS-SARPY-SEWARD-LANCASTER-CASS-OTOE-SALINE-
JEFFERSON-GAGE-JOHNSON-NEMAHA-PAWNEE-RICHARDSON-
408 PM CDT SAT APR 14 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
IOWA...WEST CENTRAL IOWA...EAST CENTRAL NEBRASKA...NORTHEAST
NEBRASKA AND SOUTHEAST NEBRASKA.

.DAY ONE...TONIGHT AND SUNDAY

NUMEROUS STRONG TO SEVERE THUNDERSTORMS ARE EXPECTED TO CONTINUE
TO MOVE ACROSS EASTERN NEBRASKA AND SOUTHWEST IOWA THROUGH THE
EVENING. LARGE HAIL AND DAMAGING WINDS ARE LIKELY WITH
A FEW TORNADOES POSSIBLE. THUNDERSTORMS WILL BECOME LESS NUMEROUS
AFTER MIDNIGHT AS A WEDGE OF DRIER AIR WORKS INTO EASTERN
NEBRASKA. A COLD FRONT WILL MOVE ACROSS EASTERN NEBRASKA ON SUNDAY
WITH GUSTY NORTHWEST WINDS MOVING INTO THE AREA BEHIND THE FRONT.

.DAYS TWO THROUGH SEVEN...SUNDAY NIGHT THROUGH SATURDAY

A FEW THUNDERSTORMS MAY OCCUR ON MONDAY INTO TUESDAY NIGHT THEN
AGAIN FROM THURSDAY INTO FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED FOR MUCH OF THE AREA THIS
EVENING.

FOBERT

In the hours before

Local storm report, Apr 14, 4:36 PM CDT, 59 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
436 PM CDT SAT APR 14 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0415 PM     HAIL             7 NE ELK CREEK          40.36N 96.03W
04/14/2012  E1.00 INCH       NEMAHA             NE   PUBLIC

&&

LANDSVORK

Local storm report, Apr 14, 4:53 PM CDT, 42 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
453 PM CDT SAT APR 14 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0452 PM     TSTM WND DMG     STERLING                40.46N 96.38W
04/14/2012                   JOHNSON            NE   TRAINED SPOTTER

            4 INCH DIAMETER TREE LIMB BLOWN DOWN. 4 BY 8 FOOT SHEET
            OF ALUMINUM ROOFING TORN OFF SHED.

&&

LANDSVORK

Local storm report, Apr 14, 5:07 PM CDT, 28 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
507 PM CDT SAT APR 14 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0500 PM     TSTM WND DMG     STERLING                40.46N 96.38W
04/14/2012                   JOHNSON            NE   TRAINED SPOTTER

            6 TO 10 INCH TREE LIMBS DOWN IN TOWN EVERYWHERE

&&

LANDSVORK

Local storm report, Apr 14, 5:12 PM CDT, 23 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
512 PM CDT SAT APR 14 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0500 PM     TSTM WND DMG     STERLING                40.46N 96.38W
04/14/2012                   JOHNSON            NE   TRAINED SPOTTER

            2 FOOT DIAMETER TREES BLOWN OVER. ANNOUNCER BOOTH AT THE
            FOOTBALL FIELD DESTROYED.

&&

VDEWALD

Local storm report, Apr 14, 5:15 PM CDT, 20 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
515 PM CDT SAT APR 14 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0513 PM     TORNADO          3 SE COOK               40.48N 96.12W
04/14/2012                   JOHNSON            NE   LAW ENFORCEMENT

&&

JMEYER

Local storm report, Apr 14, 5:32 PM CDT, 3 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
532 PM CDT SAT APR 14 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0528 PM     TSTM WND GST     NEBRASKA CITY           40.68N 95.86W
04/14/2012  M61.00 MPH       OTOE               NE   AWOS

&&

VDEWALD

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 14, 9:47 AM CDT	Special Weather Statement	OAX	Gage, Jefferson, Saline	58 min
Apr 14, 10:50 AM CDT	Severe Thunderstorm Warning	OAX	Gage, Jefferson, Saline	25 min
Apr 14, 11:15 AM CDT	Special Weather Statement	OAX	Gage	30 min
Apr 14, 11:49 AM CDT	Severe Thunderstorm Warning	OAX	Antelope, Boone	26 min
Apr 14, 12:08 PM CDT	Severe Thunderstorm Warning	OAX	Antelope, Boone, Madison, Pierce	37 min
Apr 14, 12:39 PM CDT	Severe Thunderstorm Warning	OAX	Antelope, Boone, Madison, Pierce	36 min
Apr 14, 1:08 PM CDT	Severe Thunderstorm Warning	OAX	Madison, Pierce, Stanton, Wayne	37 min
Apr 14, 1:43 PM CDT	Severe Thunderstorm Warning	OAX	Cuming, Stanton, Thurston, Wayne	32 min
Apr 14, 1:45 PM CDT	Flash Flood Warning	OAX	Cass	60 min
Apr 14, 1:53 PM CDT	Flash Flood Warning	OAX	Madison, Pierce, Stanton, Wayne	2 hr
Apr 14, 2:01 PM CDT	Flash Flood Warning	OAX	Cuming, Stanton, Thurston, Wayne	119 min
Apr 14, 2:16 PM CDT	Special Weather Statement	OAX	Cuming, Thurston	44 min
Apr 14, 2:20 PM CDT	Special Weather Statement	OAX	Jefferson	25 min
Apr 14, 3:00 PM CDT	Special Weather Statement	OAX	Saline	30 min
Apr 14, 3:09 PM CDT	Severe Thunderstorm Warning	OAX	Jefferson, Saline	51 min
Apr 14, 3:32 PM CDT	Severe Thunderstorm Warning	OAX	Johnson, Pawnee	28 min
Apr 14, 3:53 PM CDT	Severe Thunderstorm Warning	OAX	Gage, Jefferson	22 min
Apr 14, 4:00 PM CDT	Flash Flood Warning	OAX	Gage, Jefferson, Lancaster, Saline	3 hr
Apr 14, 4:00 PM CDT	Severe Thunderstorm Warning	OAX	Nemaha	30 min
Apr 14, 4:17 PM CDT	Areal Flood Advisory	OAX	Butler	3 hr
Apr 14, 4:26 PM CDT	Special Weather Statement	OAX	Gage, Johnson, Otoe	34 min
Apr 14, 4:30 PM CDT	Flash Flood Warning	OAX	Lancaster	3 hr
Apr 14, 4:43 PM CDT	Areal Flood Advisory	OAX	Cass, Gage, Johnson, Lancaster, Otoe	2 hr
Apr 14, 4:46 PM CDT	Areal Flood Advisory	OAX	Johnson, Nemaha, Otoe	2 hr
Apr 14, 4:48 PM CDT	Severe Thunderstorm Warning	OAX	Johnson, Nemaha, Otoe	27 min
Apr 14, 5:11 PM CDT	Severe Thunderstorm Warning	OAX	Nemaha, Otoe	34 min
Apr 14, 5:14 PM CDT	Tornado Warning	OAX	Nemaha, Otoe	31 min
Apr 14, 5:24 PM CDT	Tornado Warning	OAX	Otoe	24 min
Apr 14, 1:25 PM CDT	Severe Thunderstorm Warning	OAX	Fremont, Mills	35 min
Apr 14, 1:59 PM CDT	Severe Thunderstorm Warning	OAX	Mills, Montgomery	31 min
Apr 14, 2:06 PM CDT	Severe Thunderstorm Warning	OAX	Fremont, Page	24 min
Apr 14, 2:12 PM CDT	Areal Flood Advisory	OAX	Fremont, Mills, Montgomery	3 hr
Apr 14, 2:17 PM CDT	Tornado Warning	OAX	Fremont, Page	28 min
Apr 14, 2:29 PM CDT	Severe Thunderstorm Warning	OAX	Montgomery, Page	31 min
Apr 14, 2:34 PM CDT	Areal Flood Advisory	OAX	Fremont, Mills, Montgomery, Page	3 hr
Apr 14, 2:57 PM CDT	Areal Flood Advisory	OAX	Montgomery, Page	3 hr
Apr 14, 5:13 PM CDT	Flash Flood Warning	OAX	Montgomery	2 hr
Apr 14, 5:33 PM CDT	Areal Flood Advisory	OAX	Fremont	96 min
Apr 14, 5:43 PM CDT	Severe Thunderstorm Warning	OAX	Fremont, Page	32 min
Apr 14, 5:57 PM CDT	Areal Flood Advisory	OAX	Fremont, Page	2 hr
Apr 14, 5:57 PM CDT	Severe Thunderstorm Warning	OAX	Mills, Montgomery, Pottawattamie	33 min
Apr 14, 5:59 PM CDT	Areal Flood Advisory	OAX	Page	2 hr
Apr 14, 6:02 PM CDT	Severe Thunderstorm Warning	OAX	Page	28 min
Apr 14, 6:06 PM CDT	Tornado Warning	OAX	Montgomery	14 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2012 Severe Thunderstorm Warnings in Nebraska, 2012 Every severe thunderstorm warning in 2012

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.