Some Characteristics of Radar First Echoes in the High Plains

Authors

  • James R Miller, Jr. Institute of Atmospheric Sciences South Dakota School of Mines and Technology Rapid City, South Dakota
  • Paul L Smith Institute of Atmospheric Sciences South Dakota School of Mines and Technology Rapid City, South Dakota

Abstract

Radar first echoes identified in northeast Colorado and southwestern North Dakota convective clouds are examined. The first-echo temperatures in Colorado appear related to thermodynamic energy in the sounding rather than to seeding effects, when compared to earlier South Dakota studies. Mean first-echo temperatures in North Dakota are related to model-predicted maximum updraft speeds. New echoes developing near existing radar echoes have lower temperatures than ones developing far away from existing echoes. These results suggest that cloud dynamics play an important role in the temperature and height of first-echo formation. About one-third of the first-echo temperatures are higher than -5°C, which suggests that collision-coalescence rain processes may be important in High Plains clouds.

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Scientific Papers