Evaluation of high-resolution weather forecasts in tropics using satellite passive millimeter-wave observations

This paper evaluates high-resolution weather forecasts in tropics. The fifth-generation NCAR/Penn State Mesoscale Model, MM5, was used to forecast 79 storms spanning a year over Thailand and nearby regions at 5-km resolution. MM5 forecasted brightness temperatures and those coincidentally observed by the passive millimeter-wave Advanced Microwave Sounding Units (AMSU) aboard NOAA-16 satellite were compared. MM5-forecasted surface precipitation rate, peak vertical wind, and water paths for rainwater, snow, graupel, the sum of rainwater, snow, and graupel, cloud liquid water, and cloud ice were also compared with AMSU estimates. Results show that MM5 forecasts statistically agree with those observed by AMSU. MM5 over-forecast large ice particles for some storms. Morphology, intensity, and area of storms forecasted by MM5 are generally similar to AMSU observations, but with location differences. MM5 can provide useful high-resolution forecasts for tropical storms about 8 hours in advance. Forecast accuracy could be improved by using higher-resolution and more accurate initial and boundary conditions, satellite data for location correction during the forecast, and a more accurate weather prediction model.