Real-Time Wind Measurement in Extratropical Cyclones by Means of Doppler Radar

Abstract

Color displays of the velocities of precipitation particles detected with a C-band Doppler radar in wide-spread cyclonic storms provide a variety of real-time information on the atmospheric wind field.Vertical profiles of wind speed and direction indicated by the real-time color displays agree well withrawinsonde measurements. Veering winds (or warm advection) produce a striking S-shaped pattern onthe color display and backing winds (or cold advection) produce a backward S. A maximum in the verticalprofile of wind speed is indicated by a pair of concentric colored rings, one upwind and one downwind ofthe radar. Vertically sloping velocity maxima are indicated by asymmetries in the color displays, as areconfluent and difluent winds. Divergence and convergence computed from the real-time color displays areof reasonable magnitude.