Tornado Warning Decisions Using Phased Array Radar Data

Weather and Forecasting: Early Online Release

Tornado Warning Decisions Using Phased Array Radar Data

Authors:  Pamela Heinselman, Daphne LaDue, Darrel M. Kingfield, and Robert Hoffman

The 2012 Phased Array Radar Innovative Sensing Experiment identified how rapidly scanned full-volumetric data captured known mesoscale processes and impacted tornado-warning lead time. Twelve forecasters from nine National Weather Service forecast offices used this rapid-scan phased array radar (PAR) data to issue tornado warnings on two low-end tornadic and two nontornadic supercell cases. Verification of the tornadic cases revealed that forecasters’ use of PAR data provided a median tornado-warning lead time (TLT) of 20 min.  Precursors that triggered forecasters’ decisions to warn occurred within one or two typical WSR-88D scans, indicating PAR’s temporal sampling better matches the time-scale at which these precursors evolve.