Statistical post-processing of NOGAPS tropical cyclone track forecasts
Loading...
Authors
Ulses, Greg A.
Subjects
Tropical cyclone track forecasting
Navy Operational Global Atmospheric Prediction System (NOGAPS)
Statistical processing of tropical cyclone tracks
Navy Operational Global Atmospheric Prediction System (NOGAPS)
Statistical processing of tropical cyclone tracks
Advisors
Elsberry, Russell L.
Date of Issue
1998-03-01
Date
March 1998
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
A statistical post-processing technique is developed and tested to reduce the Navy global model (NOGAPS) track forecast errors for western North Pacific tropical cyclones during 1992-1996. In addition to the basic storm characteristics, the set of 42 predictors includes various track segments in the 00-72 h NOGAPS forecast as well as a 00-36 h backward extrapolation that is compared with the corresponding best-track positions. Although a NOGAPS forecast to at least 36 h is required to calculate the critical backward predictors, a reduced set of forward predictors that did not include the 48- and 72-h NOGAPS positions still produced the same improvement in track forecasts. Separate sets of statistical regressions are developed and tested for three subsets of the synoptic pattern/region combinations defined by Carr and Elsberry. For cyclones in the standard/dominant ridge combination, the improvement relative to NOGAPS is 61% after 12 h, and remains 8% after 72 h. For cyclones in the poleward/ poleward-oriented pattern/region, the improvement over NOGAPS is 55% after 12 h, and 6% after 72 h. For a combination of cyclones in all remaining pattern/ regions, the improvement relative to NOGAPS is 61% after 12 h, and 10% after 72 h. Comparison of these subsets with a single set of regression equations for all synoptic combinations showed no advantage obtained from using separate equation sets, so the single set is recommended. An independent test with all available 1997 NOGAPS forecasts decreased forecast track error by 50, 22, 12, 9, and 6% at 12, 24, 36, 48, and 72 h.
Type
Thesis
Description
Series/Report No
Department
Meteorology
Organization
Naval Postgraduate School
Identifiers
NPS Report Number
Sponsors
Funder
Format
ix, 66 p.
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.