Storm spotting

Storm spotting is a form of weather spotting in which observers watch for the approach of severe weather, monitor its development and progression, and actively relay their findings to local authorities.

Storm spotting developed in the United States during the early 1940s. A joint project between the military and the weather bureau saw the deployment of trained military and aviation lightning spotters in areas where ammunitions for the war were manufactured. During 1942, a serious tornado struck a key operations center in Oklahoma and another tornado on May 15, 1943 destroyed parts of the Fort Riley military base located in Kansas. After these two events and a string of other tornado outbreaks, spotter networks became commonplace, and it is estimated that there were over 200 networks by 1945. Their mandate had also changed to include reporting all types of active or severe weather; this included giving snow depth and other reports during the winter as well as fire reports in the summer, along with the more typical severe weather reports associated with thunderstorms. However, spotting was still mainly carried out by trained individuals in either the military, aviation, or law enforcement fields of service. It was not until 1947 that volunteer spotting, as it exists today, was born.

After a series of vicious tornado outbreaks hit the state of Texas in 1947, the state placed special emphasis on volunteer spotting, and the local weather offices began to offer basic training classes to the general public. Spotting required the delivery of timely information so that warnings could be issued as quickly as possible, thus civilian landline phone calls and amateur radio operators provided the most efficient and fastest means of communication. While phone lines were reliable to a degree, a common problem was the loss of service when an approaching storm damaged phone lines in its path. This eventually led to amateur radio becoming the predominant mean of communication and resulted in the installation of special amateur radio work zones within local weather offices. Volunteer spotters would come into the local office and run a radio net from within, directly relaying information to meteorologists.

The 1950s saw the deployment of the first dedicated weather radars in the United States, and by this time, civilian spotter networks were commonplace. The new reflectivity-only radars provided meteorologists with basic information and helped identify potentially severe storms, but due to the nature of weather radar, most precipitation was detected at a height of 1 kilometer or more above the ground. Ultimately, the radar cannot see what exactly occurs at the surface of the earth, and storm spotters now correlated ground truthing with radar signatures.

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Wikipedia