Tropical Cyclone Genesis Project

Project Description

The RAMMB Tropical Cyclone Genesis Project seeks to use observationally-based methods to improve our understanding of tropical cyclone genesis. In addition, this project facilitates the development and testing of GOES-based products that forecast tropical cyclone formation.

TC genesis locations from 1949-2006

TC Formation Probability (TCFP) Products

Currently, there are two versions of the Tropical Cyclone Formation Probability (TCFP) product running in real time. The operational NESDIS TCFP product (http://www.ssd.noaa.gov/PS/TROP/genesis.html) predicts the 24-hour probability of TC formation for each 5 x 5 latitude/longitude sub-region within the Atlantic and E. Pacific basins. The experimental TCFP product (http://rammb.cira.colostate.edu/projects/gparm/index.asp) is an updated version of the operational product that uses a longer sample dataset and larger analysis domain that includes the W. Pacific basin. Both product algorithms use a two-step process that 1) screens out all regions where TC genesis is highly unlikely and 2) performs a linear discriminant analysis and converts the resultant functional value to a TC formation probability. These steps use environmental and convective parameters, such as vertical shear and deep convective coverage, derived from the NCEP Global Forecasting System (GFS) analysis fields and GOES-E satellite water vapor (channel 3) imagery.

TCFP Operational Product Archives

The current operational product covers the Atlantic and E. Pacific basins. The operational domain has been further sub-divided into 8 sub-basins for the purpose of regional analysis of the TCFP product. In order to provide time continuity to the product, the predicted and climatological formation probabilities (environmental parameters) are summed (averaged) over each sub-basin at each analysis time and then plotted as time series, allowing for the analysis of regional-scale changes in parameter values and formation probability. The time series are archived back to 2000 for the current operational product. When the experimental product replaces the operational product in 2008, the archive will be expanded to include time series plots of the new product, which has a larger analysis domain and slightly different sub-basin boundaries.

TCFP Experimental Parameter Climatologies

During the development of the experimental TCFP product, a new climatology of each TC formation parameter was developed. These new climatology values differed than those performed for the operational product in that they covered an extended analysis domain, included an additional environmental predictor, and added two years (2004 and 2005) to the dependent dataset. Animated loops of color contour plots for each month are available for each environmental input parameter used in the experimental product. In addition, an animated loop of the global TC formation probabilities by month was generated using global Best Track files from 1949-2005 and is also available here.

The 3 main TCFP basins (left) and the Atlantic sub-basins (right).