SHIPS Rapid Intensification Index
This project has been funded, in part, by NOAAs Joint Hurricane Testbed (JHT) program.
Predicting episodes of tropical cyclone (TC) rapid intensification (RI) remains one of the highest operational forecasting priorities of the National Hurricane Center (NHC). Thus, in recent years, a statistically based rapid intensification index (RII) that employs predictors from the SHIPS model to estimate the probability of RI over the succeeding 24-h has been developed utilizing linear discriminant analysis for both the Atlantic and eastern North Pacific basins (Kaplan et al 2010). Although the SHIPS-RII is currently used as an operational forecasting tool by the NHC, its utility has been somewhat restricted since the original version was developed exclusively for a single (24-h) lead-time and its skill has tended to be rather limited particularly for the Atlantic basin.
Thus in an effort to improve the overall forecasting usefulness of the current operational SHIPS-RII, a number of model enhancements were developed as part of this recently completed Joint Hurricane Testbed (JHT) project. First, new consensus-based versions of the RII that employ both the current SHIPS-discriminant RII as well as newly developed Bayesian and logistic regression versions (Rozoff and Kossin 2011) were derived for the current 24-h operational forecast lead-time as well as the added lead times of 12-h, 36-h, and 48-h. Secondly, new versions of the rapid intensity aid that provides deterministic intensity forecasts utilizing both existing operational intensity forecast models and the probabilistic RII were developed utilizing the new multi lead-time consensus RII. Lastly, microwave imagery-based versions of the RII that have been shown to be capable of providing a more accurate measure of the overall inner-core tropical cyclone structure were derived.
A more complete description of the methodology and results of the above project can be found in the final report that was recently submitted to the JHT which can be found at: http://www.nhc.noaa.gov/jht/11-13reports/Final_Kaplan_JHT13.pdf
Kaplan, J. , J. Cione, M. DeMaria, J. Dostalek, J. Dunion, J. Knaff, J. Zhang, T. Lee, J. Hawkins, J. Solbrig, E. Kalina, and P. Leighton, 2011: Improvement in the rapid intensity index by incorporation of inner-core information. JHT final report. Available from http://www.nhc.noaa.gov/jht/09-11reports/final_Kaplan_JHT11.pdf.
Kaplan, J., M. DeMaria, and J.A. Knaff, 2010: A revised tropical cyclone rapid intensification index for the Atlantic and eastern North Pacific basins. Wea. Forecasting, 25, 220-241.
Rozoff, C. M., and J. P. Kossin, 2011: New probabilistic forecast models for the prediction of tropical cyclone rapid intensification. Wea. Forecasting, 26, 677-689.
Sampson, C. R., J. Kaplan, J. A. Knaff, M. DeMaria, and C. A. Sisko, 2011: A deterministic rapid intensification aid, Wea. Forecasting, 26, 579-585.
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