Analysis of Data from T-28 Aircraft Penetrations of a Colorado Hailstorm

Abstract

This paper describes results of two penetrations of a moderate intensity storm made by an armored T-28 aircraft on 22 July 1972 as a participant in the National Hail Research Experiment. The penetrations showed multiple updrafts and hail occurrences indicating multiple regions of hailstone growth. Furthermore, the hail encountered occurred consistently near the edges of the updraft and was accompanied by high total liquid water contents as evidenced by moderate-to-heavy icing rates at those times. Vertical sections along the penetration track show a well-defined weak-echo region with the hail occurring in the high reflectivity gradients in advance of the reflectivity maxima associated with the storm rainfall. There is also a suggestion that the hail is being size-sorted with larger hail being found in stranger updrafts. Comparisons with numerical cloud models indicate that T-28 penetrations were made just below the updraft maximum. Model predictions of hailstone diameter were approximately 5?15 mm and showed reasonable agreement with actual observations of hailfall.