Reflectivity 01:07Z (8:07 PM CDT) This radar image shows the supercell (high-precipitation supercell) as it was moving through Saline County. The red colors indicate very heavy rain or hail, with lighter rain indicated by the yellow, green, and blue colors. The tornado clipped the southern portion of the town of Wilber, with the main part of the tornado passing just south of Wilber. There is a hook echo that has completely wrapped around to form a "donut" shape echo between the towns of Wilber and De Witt. This donut echo is associated with the tornado.

Storm-Relative Velocity 01:07Z (8:07 CDT) This radar image shows the wind velocity within the supercell thunderstorm. The green and blue colors indicate winds blowing toward the radar, and the red, orange, and yellow colors indicate winds blowing away from the radar. Just southwest of Wilber the radar is showing a 105 mph wind blowing toward the radar, right next to a 69 mph wind blowing away from the radar. This is known as a "velocity couplet," and is often associated with the mesocyclone in the supercell. The radar typically does not actually measure the winds inside the tornado, but rather the "parent" mesocyclone that the tornado forms out of.

Reflecitivity 01:24Z (8:24 PM CDT) This reflectivity image shows a more classic looking hook echo, moving out of Saline County and into the northwest corner of Gage county and the southwest corner of Lancaster County. The hook echo, and the associated tornado, is between Hallam and Wilber.

Reflectivity 01:28Z (8:28 PM CDT) The hook echo now stretches from the town of Claytonia to the town of Hallam

Storm-Relative Velocity 01:28Z (8:28 CDT) The velocity couplet is shown just west of Hallam, about to move into the Hallam area. The wind speeds, as indicated by the radar, in the mesocyclone are 83 mph toward the radar and 100 mph away from the radar.

Tornadoes left a path of destruction 52 miles long and 2 1/2 miles wide at one point.


The entire area around Hallam takes a terrible blow from the tornado outbreak.
   

Tornadoes damaged 95 percent of homes and businesses in the small Lancaster County town
of Hallam Nebraska.  

The images will speak for themselves as to how terrible this tornado was and how devastating.

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More photos taken shortly after event.

National Weather Service Information
Below is Courtesy of the NWS in Nebraska
Public Information Statement...  Correction national weather service omaha/valley ne
400 pm cdt tue may 25 2004 ... Damage survey report on the Hallam Nebraska tornado ...
A survey was conducted by the national weather service in Valley, NE of the tornado that struck Hallam on Saturday, may 22nd. the following is an overview of damage along the track. The tornado started 2 miles north of Daykin, NE and traveled east-northeast to about 1 mile south of western and continued to about 2 miles north of Swanton. the tornado was rated f0 to f1 on the fujita damage scale in this section. Much of the damage was due to farm outbuildings, grain bins and trees. the tornado remained f0 to f1 until it struck the southern portions of Wilber where it strenghthened to f2.

Roofs blown off of homes occurred just southeast of Wilber. the tornado from Wilber to north of clatonia to Hallam grew to its most intense stage. The tornado's path width also increased to an unprecedented two and one-half miles. the f-scale rating for the storm was f4 from about clatonia to Hallam. many well-built homes were demolished.
Grain bins, farm sheds and outbuildings, and trees were demolished along this section of the path. Hallam itself escaped the strongest winds of the storm, which were south of the town. nevertheless, many of the structures in Hallam were rated f2 to f3.

The storm also toppled hopper cars from a freight train on the west side of the town. the tornado then tracked east for several miles prior to turning northeast again. The storm narrowed to about a mile wide as it passed just north of Cortland and about 2 miles north of firth. the Norris schools north of firth received severe damage with the roof of the middle school auditorium collapsed and several walls caved in.

School busses were tossed. several homes northeast of the schools were flattened where the storm was again rated f4. damage continued northeast to Holland and 2 miles north of Panama. The tornado was slghtly weaker in this section (f2 at the most) and began to narrow. the track then curved more to the north, just to the south of bennet where some homes received f3 damage.
After passing to the south of Bennet, the storm moved back to the northeast and began to weaken to f0 to f1 strength. The track also was becoming narrower. the tornado then dissipated 1 mile west of Palmyra.

In summary. f-scale rating: f4 path length: 52 miles maximum path width: 2 1/2 miles the fujita damage scale is as follows: f0 less than 73 mph chimneys damaged, trees broken f1 73-112 mph mobile homes moved off foundations or overturned f2 113-157 mph considerable damage, mobile homes demolished, trees uprooted f3 158-206 mph roof and walls torn down, trains overturned, cars thrown f4 207-260 mph well-constructed walls leveled f5 261-318 mph homes lifted off foundations and carried some distance, cars thrown a long distance. more information and pictures will be posted on the national weather service web site at www.crh.noaa.gov/oax/ brian e. smith warning coordination meteorologist national weather service Omaha/valley NE .end

Storm-Relative Velocity 01:33Z (8:33 CDT) The tornado was passing over Hallam at 8:33 PM, and the radar velocity winds were 79 mph toward the radar and 92 mph away from the radar. Because the radar is measuring the winds in the mesocyclone, the wind speeds do not necessarily correlate to the strength of the tornado, because the tornado was rated a F4 at the time of this radar image. There are many factors and variables which determine the radar's ability to measure the wind speeds inside the mesocyclone. Despite the slightly lower winds on the radar, this is still considered an extremely strong velocity couplet. Thanks to the National Weather Service for providing the Radar Images.

Tornado Alley News Report December 2004 by Tornado Tim
Continuing research helps shed light on the idea of multiple tornado alleys in the US rather than one general area. Reading the research paper  "EVIDENCE OF SMALLER TORNADO ALLEYS ACROSS THE UNITED STATES BASED ON A LONG TRACK F3 TO F5 TORNADO CLIMATOLOGY STUDY FROM 1880 TO 2003" by  Chris Broyles and Casey Crosbie of the Storm Prediction Center in Norman, Oklahoma; data has been analyzed to show a historical representation of several smaller apparent tornado alleys across the United States as determined by a long track F3 to F5 tornadoes. A map of the United States from 1880 to 2003 was constructed showing normalized frequencies of F3 to F5 tornadoes with path lengths of at least 25 miles.  This research gives a well needed upgrade to how we look at tornado prone areas in the US and I believe helps give a more accurate representation of areas not always known as tornado alley. I continue to believe most tornado alley maps do not represent the most dangerous areas in the US correctly, and have been vague in defining them to the public which may become a serious safety issue in the future.  I continue to believe we need to go to maps showing multiple tornado alleys in the US and not ignore overwhelming evidence that many of the most violent tornado areas in the US have been left off tornado alley maps for too long. While it may be true that torando frequency may be highest in a small area in the US on a yearly basis, dangerous and violent tornadoes happen over many tornado alley sections within the US that may have prolonged droughts of tornadoes before being anilated by large, long lived tornadoes again and again. These small tornado alleys are seen when looking at the US by a county to county assesment. Below are the most dangerous counties in the US for F3 to F5 tornadoes with path lengths longer than 25 miles. Most of these dangerous counties are not listed on most tornado alley maps. Maps based on this county by county look is far more accurate than todays maps.
(To find the number of long path F3 to F5 tornadoes affecting a county from 1880 to 2003, multiply the frequency by the square miles and divide by 1,000).
Below are the top nine areas.

     Notice the two counties listed above from Nebraska.  These two counties border each other in southeast Nebraska.  Fillmore and Thayer Counties, had the highest frequencies in the Great Plains with 15.63 and 13.91 long path F3 to F5 tornadoes per 1,000 square miles, respectively. Nine long path F3 to F5 tornadoes affected Fillmore County and eight affected Thayer County during the 124 year period. In the great plains Nebraska comes above any listing for Kansas, Texas or Oklahoma which none of those 3 made the top 9 list.

      In 2004 Lancaster county in Southeast Nebraska had a long lived tornado that had a peak width of around 2 1/2 miles wide destroying the city of Hallam Nebraska proving the area to be one of the most dangerous in the US. The tornado event started 2 miles north of Daykin Nebraska, which is less than 5 miles from both Fillmore and Thayer Counties. In summary. f-scale rating was a maximim of f4 with a   maximum path length of 52 miles.

Also according to this research paper it says that the: "area with very high frequency of long path F3 to F5 tornadoes includes northern Mississippi, northern Alabama and western Tennessee. This vicinity includes the largest continuous area with six or greater long track F3 to F5 tornadoes per 1,000 square miles in the United States which is across northern Alabama extending to the northwest into western Tennessee. Union County in northeast Mississippi had the highest frequency in the United States with 19.28 long track F3 to F5 tornadoes per 1,000 square miles. The relatively small county had eight long track F3 to F5 tornadoes during the 124 year period."

Under their summary of this informative research paper they state the following information:
"The four most prominent tornado alleys that were identified in the United States include south-central Mississippi, east-central to northeast Oklahoma, southeast Nebraska and the area from western Tennessee to northeast Mississippi and northern Alabama. Other prominent alleys include northeast Kansas to central Iowa, northeast Arkansas, northwest Georgia, central Illinois to northwest Ohio, northwest Louisiana, northeast Nebraska, southeast Missouri to southwest Ohio and east to southeast North Carolina."

Most people would not be surprised to find that Oklahoma has one of the most dangerous cities in the US using this data, but look at the list of other cities toping the list. Below is the top 9 Cities for Long Track F3 to F5 Tornadoes in the United States from 1880 to 2003. The frequency of long track F3 to F5 tornadoes per 1,000 square miles is given for each city as a value.

Thanks again to the following research paper as much of this information came from it.  Credit to: "EVIDENCE OF SMALLER TORNADO ALLEYS ACROSS THE UNITED STATES BASED ON A LONG TRACK F3 TO F5 TORNADO CLIMATOLOGY STUDY FROM 1880 TO 2003" by  Chris Broyles and Casey Crosbie of the Storm Prediction Center in Norman, Oklahoma.NOTE:Many of the opinions in this article are the ideas and opinions of Tornado Tim.