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xx dBZ Echo Top (ET)

xx dBZ Echo Top (ET)

Short Description

The maximum altitude for a particular reflectivity value (e.g., 18 dBZ) within a vertical column.


18 dBZ ET

30 dBZ ET

50 dBZ ET

60 dBZ ET

Primary Users



Input Sources

3D Reflectivity Cube


Spatial Resolution: 0.01o Latitude (~1.11 km) x 0.01o Longitude (~1.01 km at 25oN and 0.73 km at 49oN)

Temporal Resolution: 2 minutes

Product Creation

At each horizontal 2D grid point, the reflectivity values at the vertical grid points are checked from the top-down. Once the ET threshold value for the particular sub-product is equaled or exceeded, that altitude and the altitude at the next-highest grid point are used to compute the ET value using linear interpolation based on the slope of the reflectivity value between those two altitudes.

Technical Details

Latest Update: MRMS Version 11.5


Elliott, M., 2013: Electrical discharges in the overshooting tops of thunderstorms. M. S. Thesis, School of Meteorology, University of Oklahoma, 139 pp.

Lakshmanan, V., A. Fritz, T. Smith, K. Hondl, and G. J. Stumpf, 2007: An automated technique to quality control radar reflectivity data. J. Appl. Meteor., 46, 288-305.

Lakshmanan, V., K. Hondl, C. K. Potvin, and D. Preignitz, 2013: An improved method for estimating radar echo-top height. Wea. Forecasting, 28, 481-488.

Maddox, R. A., D. S. Zaras, P. L. MacKeen, J. J. Gourley, R. Rabin, and K. W. Howard, 1999: Echo height measurements with the WSR-88D: Use of data from one versus two radars. Wea. Forecasting, 14, 455-460.