Imperial, California short periods of time. The precipitation in the winter months is predominantly rain showers from the occasional winter storms. At times these storms bring cold temperatures to Imperial and surrounding cities, and mountain snowfall to the nearby mountains. Snow is almost totally unknown in the city, except for a powerful winter storm that covered the entire valley with 4 inches snow on December 12, 1934 and a very brief fall of sleet mixed with hail during a shower in December 1967. On average there are about 11 days that dip into the mid to lower 30s. In January, the normal
Hail the hail to the radar, and the echo is further away from the radar than the actual location of the hail on the same radial path, forming a cone of weaker reflectivities. More recently, the polarization properties of weather radar returns have been analyzed to differentiate between hail and heavy rain. The use of differential reflectivity (formula_1), in combination with horizontal reflectivity (formula_2) has led to a variety of hail classification algorithms. Visible satellite imagery is beginning to be used to detect hail, but false alarm rates remain high using this method. The size of hailstones is best determined by