IAU alike Initialization Applied to HWRF for Hurricane Forecast

Satellite data assimilation has been applied in operational HWRF since 2013. One big problem from DA is the spin-up and spin-down in first a few hours of forecast. This is because the analysis increment has the non-balanced component, which results in big model adjustments. To reduce the big spin-up and spin-down, an IAU alike initialization scheme was applied to WRF model integration. The initial tests show positive impact when comparing against with control runs where no IAU was applied.