14A.3
High resolution SST in the SHIPS model: improving operational guidance of tropical cyclone intensity forecasts
Robbie Berg, NOAA/NWS/NCEP/TPC/NHC, Miami, FL; and C. Sisko and M. DeMaria
Operational forecasting of tropical cyclone intensity at the National Hurricane Center (NHC) relies heavily on the Statistical Hurricane Intensity Prediction Scheme (SHIPS) model. The model currently uses a weekly-updated Reynold’s sea-surface temperature (SST) field to account for temporal changes in the SST structure. However, atmospheric and oceanic processes often occur on time scales of less than a week (such as the recent passage of a tropical cyclone), and the Reynold’s analysis may not capture the latest changes in the SST. This study utilizes the National Centers for Environmental Prediction (NCEP) Global SST data to more accurately reflect day-to-day and spatial variations in the SST structure for input into the SHIPS model. The NCEP analysis uses ship, buoy, and satellite-retrieved SST measurements and variable averaging and weighting schemes to produce a ½° gridded analysis, yielding higher spatial resolution compared to the 1° gridded Reynold’s SST. Results suggest that the SHIPS intensity guidance benefits from this high spatial and temporal resolution SST with the greatest reduction in forecast errors occurring at forecast periods beyond 3 days. For the 2002 hurricane season as a whole, this method improves forecast intensity errors at all forecast times with the greatest improvement occurring at days four and five. Forecast intensity errors are reduced by a maximum of 9.5% in the Atlantic and a maximum of 11.7% in the East Pacific compared to the operational SHIPS output at the respective forecast intervals.
Session 14A, Tropical cyclone intensity change III: Statistical-Dynamical Models
Thursday, 6 May 2004, 1:30 PM-3:15 PM, Le Jardin Room
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