A comparison of the fine-scale structures of a prefrontal wind-shift line and a strong cold front in the Southern Plains of the U. S.

Abstract

he objectives of this study are to determine the fine-scale characteristics of the wind and temperature fields associated with a prefrontal wind-shift line and to contrast them with those associated with a strong cold front. Data from a mobile, polarimetric, X-band, Doppler radar and from a surveillance S-band radar, temperature profiles retrieved from a thermodynamic sounder, and surface-observations from the Oklahoma Mesonet are used to analyze a prefrontal wind-shift line in Oklahoma on 11 November 2013. Data from the same mobile radar and the Oklahoma Mesonet are used to identify the fine-scale characteristics of the wind field associated with a strong surface cold front in Oklahoma on 9 April 2013. It is shown that the prefrontal wind-shift line has a kinematic and thermodynamic structure similar to that of an intrusion (elevated density current), while the cold front has a kinematic structure similar to that of a classic density current. Other characteristics of the prefrontal wind-shift line and front are also discussed. Evidence of waves generated at the leading edge of the prefrontal wind-shift line is presented.