The impact of Omega dropwindsonde observations on barotropic hurricane track forecasts

Abstract

During these synoptic-flow experiments, Omega dropwindsondes (ODWs) are released from the two NOAA WP-3D research aircraft over a 9-10h period in the hurricane environment. Recently, a barotropic, nested, spectral hurricane track forecasting model, VICBAR, has been developed at HRD. The VICBAR model is used to evaluate the impact of ODW data on track forecast error for the 14 HRD synoptic-flow experiments. The ODW data produced highly consistent reductions in forecast errors in this sample of cases. Forcast improvements due to single-level midtropospheric (aircraft) data were significantly smaller than those due to the ODWs. At the important verification times of 24-36h (prior to landfall), when the decision to issue a hurricane warning is being made, the ODWs reduced the model mean forecast error by 12%-16%. These improvements, statistically significant at the 99% level, are comparable to the total improvement in normalized NHC official 24h forecast error occurring over the past 20-25yr. -from Authors