Severe Weather Forecasts using the Space and Time Mesoscale Analysis System (STMAS)

Severe weather events cause tremendous property damage and life loss every year worldwide. To improve severe weather forecasts, data assimilation techniques are very critical in forecasting hurricane and storms. The Space and Time Mesoscale Analysis System (STMAS) developed at NOAA/Earth System Research Laboratory/Global Systems Division is a multigrid variational data assimilation system, which provides a multiscale and inhomogeneous analysis. Several hurricane cases (e.g., Katrina 2005) in the Atlantic Basin in recent years are selected to run the forecasts using the STMAS initialization in the Weather Research and Forecasting (WRF) model. Hurricane intensity, track, and rainfall bands are analyzed for each case. The SMTAS also helps the typhoon forecasting in the Pacific Basin. Another example is a tornado case occurred in Windsor, Colorado in May 2008. All the forecasts under various scenarios show that the STMAS can improve the forecasts for different resolutions from regional to local scales. More tests on the data impact on the forecasting using the STMAS technique are desirable.