Tropical Cyclone-like Vortices Detection in the NCEP 16-Day Ensemble System over the Western North Pacific in 2008: Application and Forecast Evaluation
Elsberry, Russell L.
MetadataShow full item record
An automated technique has been developed for the detection and tracking of tropical cyclone–like vortices (TCLVs) in numerical weather prediction models, and especially for ensemble-based models. A TCLV is detected in the model grid when selected dynamic and thermodynamic fields meet specified criteria. A backward-and-forward extension from the mature stage of the track is utilized to complete the track. In addition, a fuzzy logic approach is utilized to calculate the TCLV fuzzy combined-likelihood value (TFCV) for representing the TCLV characteristics in the ensemble forecast outputs. The primary objective of the TCLV tracking and TFCV maps is for use as an evaluation tool for the operational forecasters. It is demonstrated that this algorithm efficiently extracts western North Pacific TCLV information from the vast amount of ensemble data from the NCEP Global Ensemble Forecast System (GEFS). The predictability of typhoon formation and activity during June–December 2008 is also evaluated. The TCLV track numbers and TFCV averages around the formation locations during the 0–96-h period are more skillful than for the 102– 384-h forecasts. Compared to weak tropical cyclones (TCs; maximum intensity # 50 kt), the storms that eventually become stronger TCs do have larger TFCVs. Depending on the specified domain size and the ensemble track numbers to define a forecast event, some skill is indicated in predicting the named TC activity. Although this evaluation with the 2008 typhoon season indicates some potential, an evaluation with a larger sample is necessary to statistically verify the reliability of the GEFS forecasts.
The article of record as published may be located at http://dx.doi.org/10.1175/2010WAF2222415.1
Showing items related by title, author, creator and subject.
Stubblefield, Cedrick L. (Monterey, California. Naval Postgraduate School, 2011-09);The Air Force Weather Agency (AFWA) is currently producing cloud-free forecasts for several agencies, but operational forecasts do not incorporate forecast uncertainty. Uncertainty can be forecasted via an ensemble created ...
Warren, Steven W. (Monterey, California. Naval Postgraduate School, 1993-03);A continuing trend in numerical weather prediction (NWP) is the desire for reduced model forecast error. Developments in NWP such as advanced computing power and improved model physics and analysis methods have been ...
Chilcoat, Kenneth H. (Monterey, California. Naval Postgraduate School, 2012-03);Observation network design requires some framework for sensitivity studies. The goal is to place observations where they will reduce forecast error the most. We use uncertainty estimates from our best forecast models as ...