Alert archive / Nebraska / Tornado Watches in 2001

Tornado Watch 133

April 11, 200114 counties in Iowa; 7 counties in Missouri; 36 counties in Nebraska

The Storm Prediction Center issued this tornado watch at Apr 11, 2001, 10:45 AM CDT for 14 counties in Iowa; 7 counties in Missouri; 36 counties in Nebraska. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 11, 2001, 10:45 AM CDT (15:45 UTC)
Expired
Apr 11, 2001, 4:00 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
All 57 counties

Adams County, IA, Cass County, IA, Crawford County, IA, Fremont County, IA, Harrison County, IA, Mills County, IA, Monona County, IA, Montgomery County, IA, Page County, IA, Pottawattamie County, IA, Ringgold County, IA, Shelby County, IA, Taylor County, IA, Woodbury County, IA, Atchison County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Holt County, MO, Nodaway County, MO, Worth County, MO, Antelope County, NE, Boone County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Colfax County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Douglas County, NE, Gage County, NE, Holt County, NE, Johnson County, NE, Lancaster County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Pierce County, NE, Platte County, NE, Polk County, NE, Richardson County, NE, Rock County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Stanton County, NE, Thurston County, NE, Washington County, NE, Wayne County, NE, Wheeler County, NE, York County, NE

The radar

The Omaha radar (KOAX), 26 km from the middle of the area, began a volume at 15:47 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.

Warnings issued inside it

14 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Apr 11, 10:50 AM CDTTornado WarningEAXAndrew, Gentry40 min
Apr 11, 11:21 AM CDTTornado WarningEAXWorth24 min
Apr 11, 11:32 AM CDTTornado WarningDMXRinggold33 min
Apr 11, 12:00 PM CDTTornado WarningDMXRinggold, Union40 min
Apr 11, 12:38 PM CDTTornado WarningOAXMills37 min
Apr 11, 12:45 PM CDTTornado WarningOAXPottawattamie30 min
Apr 11, 1:04 PM CDTTornado WarningOAXHarrison26 min
Apr 11, 1:12 PM CDTTornado WarningOAXPottawattamie18 min
Apr 11, 1:29 PM CDTTornado WarningOAXShelby31 min
Apr 11, 1:30 PM CDTTornado WarningOAXHarrison30 min
Apr 11, 1:40 PM CDTTornado WarningOAXMonona35 min
Apr 11, 1:55 PM CDTSevere Thunderstorm WarningDMXCrawford35 min
Apr 11, 1:56 PM CDTTornado WarningFSDWoodbury34 min
Apr 11, 2:28 PM CDTTornado WarningFSDWoodbury32 min

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 3.8 hours before the alert went out and 26 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 2001-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 12:00Z on 2001-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1274 m above ground
0-6 km bulk shear
77 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
163 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 
WWUS9 KMKC 111528
SEL3  

SEL3  
MKC WW 111524
IAZ000-NEZ000-112100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 133
STORM PREDICTION CENTER NORMAN OK
1024 AM CDT WED APR 11 2001

THE STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

   WESTERN IOWA                               
   EASTERN NEBRASKA                           

EFFECTIVE THIS WEDNESDAY MORNING AND AFTERNOON FROM 1045 AM UNTIL
400 PM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 95 STATUTE MILES EAST AND WEST
OF A LINE FROM 40 MILES NORTH NORTHWEST OF NORFOLK NEBRASKA TO 30
MILES EAST OF FALLS CITY NEBRASKA.

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. 
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.

OTHER WATCH INFORMATION...  CONTINUE...WW 130...WW 131...WW 132...

DISCUSSION...INTENSE CYCLONE MOVING NEWD FROM WRN KS ACROSS CENTRAL
NEB THIS AFTERNOON. STRONG SHEAR PROFILES AND UPWARD MOTION FIELDS
AHEAD OF LOW.  CONDITIONS  FAVORABLE FOR DEVELOPMENT OF TORNADIC
SUPERCELLS ALONG/AHEAD OF COLD FRONT MOVING NEWD INTO ERN NEB.


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOF>T TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400. 
MEAN STORM MOTION VECTOR 20035.


...HALES

;400,0964 423,0993 423,0955 400,0931;

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 11, 2:00 AM CDTTornado WatchSPCCrawford, Fremont, Harrison, Mills, Monona, Pottawattamie and 1 more5 hr
Apr 11, 4:00 AM CDTSevere Thunderstorm WatchSPCAdair, Adams, Appanoose, Audubon, Boone, Carroll and 21 more5 hr
Apr 11, 12:00 PM CDTTornado WatchSPCAdair, Appanoose, Audubon, Benton, Black Hawk, Boone and 46 more5 hr
Apr 11, 4:00 PM CDTTornado WatchSPCAllamakee, Benton, Black Hawk, Bremer, Buchanan, Butler and 40 more6 hr
Apr 10, 7:00 PM CDTSevere Thunderstorm WatchSPCAudrain, Franklin, Jefferson, Lincoln, Montgomery, Saint Charles and 4 more5 hr
Apr 11, 6:15 AM CDTTornado WatchSPCBarry, McDonald, Newton, Stone6 hr
Apr 11, 9:30 AM CDTTornado WatchSPCAndrew, Barton, Bates, Benton, Buchanan, Caldwell and 47 more6 hr
Apr 11, 10:00 AM CDTSevere Thunderstorm WatchSPCButler, Carter, Douglas, Howell, Oregon, Ozark and 2 more5 hr
Apr 11, 1:00 PM CDTTornado WatchSPCAdair, Audrain, Boone, Callaway, Clark, Cole and 20 more6 hr
Apr 10, 10:15 PM CDTSevere Thunderstorm WatchSPCAdams, Boone, Buffalo, Clay, Fillmore, Franklin and 17 more6 hr

Nearby

Tornado Watches in Nebraska, 2001Tornado Watches in Iowa, 2001Tornado Watches in Missouri, 2001Every tornado watch in 2001

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.