The Bureau would later be moved to the Department of Commerce in 1940. On July 12, 1950, bureau chief Francis W. Reichelderfer officially lifted the agency's ban on public tornado alerts in a Circular Letter, noting to all first order stations that "Weather Bureau employees should avoid statements that can be interpreted as a negation of the Bureau's willingness or ability to make tornado forecasts", and that a "good probability of verification" exist when issuing such forecasts due to the difficulty in accurately predicting tornadic activity. However it would not be until it faced criticism for continuing to refuse to provide public tornado warnings and preventing the release of the USAF Severe Weather Warning Center's tornado forecasts (pioneered in 1948 by Air Force Capt. Robert C. Miller and Major Ernest Fawbush) beyond military personnel that the Bureau issued its first experimental public tornado forecasts in March 1952. In 1957, the Bureau began using radars for short-term forecasting of local storms and hydrological events, using modified versions of those used by Navy aircraft to create the WSR-57 (Weather Surveillance Radar, 1957), with a network of WSR systems being deployed nationwide through the early 1960s; some of the radars were upgraded to WSR-74 models beginning in 1974.
Intensifying high pressure is producing dangerous heat and humidity in the south-central U.S. with heat indexes possibly exceeding 110. Triple digit heat will also continue for some western areas. Elsewhere, a front moving through the central U.S. may produce severe thunderstorms and heavy rainfall in parts of the Plains and MS Valley through Friday. Read More >