Wednesday, 25 January 2012: 4:45 PM
Short-Term Storm Forecasting From Blending Satellite-Based Extrapolation Forecasts with NWP Model Outputs Over the Gulf of Mexico
Room 256 (New Orleans Convention Center )
Deep convection over the ocean poses a potentially great danger for trans-oceanic flights, as tragically demonstrated by the Air France Flight 447 accident of 2009. This paper describes a forecasting system that will produce 0-12 hr convective forecasts over the Gulf of Mexico domain using a blending technique that combines satellite-based extrapolation forecasts with Numerical Weather Prediction (NWP) model forecasts. Closely following the steps of the Federal Aviation Administration (FAA) Aviation Weather Research Program (AWRP) CoSPA development, a forecasting system is being developed to blend satellite-derived rain rate and cloud top height with their corresponding fields derived from the Global Forecasting System (GFS) NWP model. Forecasts will be computed over the 0-12 hr time frame within a domain that encompasses the greater Gulf of Mexico and parts of the continental United States. Considering the relative strength of the NWP model and the satellite-based extrapolation forecasts, a weighted-average technique, similar to what is being used in CoSPA, is being tested. The weights are determined by historical performance of extrapolation and model forecasts as a function of forecast lead time. Tests of various extrapolation techniques have been completed and an optimum technique has been selected. The GFS rain rate forecast performance statistics have been compiled. A prototype blended forecasting system for oceanic convection is under construction and preliminary results of the blended forecasting system will be reported at the conference.