A bulk ABL similarity approach was used to make regional estimates of the sensible heat flux by combining surface temperature measurements with mixed layer temperature and wind speed profiles. The mixed layer profiles were measured by a 915 MHz Profiler/Radio Acoustic Sounding System and by radiosondes in north-central Oklahoma at the ARM Southern Great Plains CART Central Facility. A comparison of calculated sensible heat flux values with regional mean values measured at two ground stations showed good agreement with r=0.88 and r=0.76 for the 915 MHz profiler and the radiosonde data sets, respectively. Estimates of friction velocity u* by means of radiosonde wind profiles gave good results when compared to values measured by an surface eddy correlation system with a correlation coefficient r=0.77. However, u* values obtained from wind profiles measured by the 915 MHz profiler were underestimated, because these velocity measurements were systematically too small. The results also show that the 915 MHz Profiler/Radio Acoustic Sounding System is capable of providing the needed temperature measurements to make reasonable regional estimates of sensible heat flux.