3D.2
NCEP Global Model Tropical Forecast Upgrades: Model Performance during the 2001 Hurricane Season
Hua-Lu Pan, NOAA/NWS/NCEP, Camp Springs, MD; and Q. Liu, N. Surgi, and S. Lord
During the 2001 hurricane season there has been a dramatic increase in the skill of the tropical storm track forecasts of the NCEP global forecast system. This increase in skill has been the result of several years of upgrades to the NCEP Global Model analyses, model physics and the replacement of the former AVN synthetic vortex with an improved storm representation commensurate with an increase in model resolution. The upgrade to the analyses includes the assimilation of the NOAA AMSU-B data and additional AMSU-A data from NOAA-16, GOES radiance data and a physical initialization for the tropics using the SSM/I precipitation estimates. The upgrades to the physics include the explicit prediction of liquid water, explicit cloud radiative feedback from the prognostic clouds, and the addition of cumulus momentum mixing in the deep clouds. These changes have greatly improved the large scale tropical climatology and have ameliorated a low level spin up problem that created model false alarms. A new storm location algorithm has provided a more realistic storm representation in the model. The result of these upgrades is a much improved NCEP global model hurricane track forecast. We will present the steps taken at EMC which have led to these improvements.
Session 3D, Tropical Cyclone Prediction (Parallel with Sessions 3A, 3B, & 3C)
Monday, 29 April 2002, 4:00 PM-5:30 PM
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