2C.3
Estimating the probability of rapid intensification using the SHIPS model output: Some preliminary results
John Kaplan, NOAA/AOML/HRD, Miami, FL; and M. DeMaria
The unexpected rapid intensification (RI) of several recent hurricanes (e.g., Opal (1995), Bret (1999), and Keith (2000) ) has prompted the National Hurricane Center (NHC) to rank improving the capability to forecast the timing, duration, and magnitude of episodes of rapid intensification as one of their highest forecast priorities. Since current operational intensity prediction models have not yet demonstrated the ability to predict such events, an effort has been undertaken to employ the SHIPS model output to estimate the probability of RI for a 24 h period. The goal of this effort is to provide a tool that can be employed operationally by the NHC to help predict the occurrence of RI events. To accomplish this goal, a statistical analysis of the 1989-2000 SHIPS database was performed. The mean magnitudes of the SHIPS predictors were computed for those cases that underwent RI as well as for those that did not. Thresholds for RI were then determined for those predictors for which statistically significant differences existed between the RI and non-RI samples. These thresholds were equivalent to the mean initial predictor magnitudes of the RI cases. During the 2001 hurricane season, estimates of the probability of RI were provided in real-time to the NHC for the first time. These estimates were obtained by comparing the magnitudes of various operational SHIPS predictors to the RI thresholds determined previously during statistical analysis of the 1989-2000 SHIPS database. This paper will show results from these first year attempts to estimate the probability of RI. In addition, techniques for improving these probability estimates will be explored.
Session 2C, Tropical Cyclone Intensity Change (Parallel with Sessions 2A, 2B, and 2D)
Monday, 29 April 2002, 2:00 PM-3:30 PM
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