| The first Doppler weather radar was | | | | from regular storms. And as time went on, they |
| commissioned in 1964 by the National Oceanic and | | | | were able to recognize this pattern, which they |
| Atmospheric Administration, or NOAA. When | | | | later called the "tornadic vortex" signature. |
| scientists experimented with tornadoes, they | | | | Doppler weather radar improvements, including |
| quickly realized the 3-cm Doppler was not big or | | | | NEXRAD (Next Generation Radar), increased the |
| powerful enough to receive and track all of the | | | | warning time and the path prediction accuracy in |
| needed information. They realized this one radar | | | | storms with tornadic activity. Using NEXRAD, |
| would need improvements. | | | | scientists nationwide are able to share data, giving |
| The National Severe Storms Laboratory (NSSL) | | | | a clearer picture of what to expect. In 2007, the |
| observed NOAA's upgraded 10-cm Doppler in | | | | National Weather Service picked up on tornadic |
| 1973, which was able to track a tornado's life | | | | cloud rotation and signature "hook-echo" patterns. |
| cycle. This data told scientists of the circular | | | | Residents of Enterprise, Alabama were warned to |
| motion of a tornado's winds, as well as the | | | | take cover, and a full eighteen minutes later the |
| centripetal point of rotation, which the inner clouds | | | | tornado touched ground. Thanks to NEXRAD, the |
| rotate around. | | | | previous, typical five minute warning time to get |
| Scientists sought to increase their knowledge of | | | | to a safe place finally saw a dramatic increase. |
| how storms like these formed. One particular | | | | Eighteen minutes is ample time to gather family |
| storm in May of 1973 cut right through the heart | | | | and emergency supplies and take shelter. It was |
| of Union City, Oklahoma. Union City lies in the | | | | also enough time for some commuters to seek |
| center of the infamous "Tornado Alley" region of | | | | shelter in a sturdy building and get off the streets. |
| the United States. With the data received by the | | | | It is the goal of all meteorologists to increase the |
| scientists, they were able to start planning | | | | lead time to 20 minutes, saving many more lives |
| upgrades and improvements of the Doppler | | | | in the process. |
| weather radar so it could be a more reliable asset | | | | Doppler weather radar has come a long way. In |
| to the government and the residents. | | | | the beginning, scientists hoped to save lives by |
| The Doppler system maps weather radar by | | | | getting the severe weather reports announced |
| measuring the motion inside these very hostile | | | | faster. Now, almost forty-five years since its |
| storms. Over time, scientists discovered that | | | | birth, this one radar system is doing exactly that. |
| tornadoes produce a unique signature; different | | | | |