Fig. 3. Hourly mean absolute and rms differences of temperature (K), dew point (K), and wind vector (m/s) for the three experiments (AVN = short dashed line = expt 1, NOQ = long dashed line = expt 2, MM5 = solid line = expt 3). Differences are computed by subtracting all NWS surface observations available within the model domain from the MM5 forecasts. Between 700 and 800 observation locations were typically available at each forecast hour.