Vibrationally excited hydroxyl radicals OH(v″=9) are produced following the laser photolysis of O3/H2/He mixtures at 248 nm. The temporal profile of OH(v″=9) density was monitored by observation of the Δv=6 emission near 625 nm. Variation of the ozone pressure yields an estimate of the rate of vibrational relaxation of OH(v″=9) by O3, k≈2¿10-10 cm3 molecule s-1. Comparison of the observed overtone emission intensity with that arising from the O(21D2) precursor at 630 nm yields a factor-of-two estimate of the Einstein coefficient for spontaneous emission. A9→3≈0.006 s-1. This is in agreement with a previous experimental study, but does not support a theoretical value that has been extensively utilized in modeling of atmospheric Meinel emission intensity.