Download or read book An Analysis of the Error Characteristics of Atlantic Tropical Cyclone Track Prediction Models written by James T. Kroll and published by . This book was released on 1987 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using 140 track forecasts between 1976-1985, the error characteristics of the National Hurricane Center's tropical cyclone track prediction models are assessed with special emphasis on the Moveable Fine Mesh (MFM) model. The results indicate that beyond the 12-hour forecast, the MFM has the lowest mean forecast error of the NHC models. The forecast error component, relative to storm motion, are also analyzed. The MFM displayed the smallest mean across-track error, which is a measure of the accuracy of the path of movement. A consensus style track forecast known as the Combined Confidence Weighted Forecast (CCWF) scheme is tested using the track prediction output from NHC models. The CCWF provides improved track forecasts at 12 and 24 hours relative to the individual track prediction models. The CCWF scheme, on average, is also more accurate than the official forecast disseminated by NHC. An attempt is made to develop linear regression models, using independent variables which describe storm characteristics and the large-scale wind field, l to predict the magnitude of the NHC track prediction model forecast errors. Finally, a spectral barotropic model is used to identify the effects that sparse data and initial position errors have upon track forecast errors. Various scales of motion are removed from the initial wind field to test the effect of sparse data. Theses. (fr).
Download or read book Analysis of the Error Characteristics of Atlantic Tropical Cyclone Track Prediction Models written by and published by . This book was released on 1900 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Geosciences written by Kenji Satake and published by World Scientific. This book was released on 2012 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: This invaluable volume set of Advances in Geosciences continues the excellent tradition of the Asia-Oceania scientific community in providing the most up-to-date research results on a wide range of geosciences and environmental science. The information is vital to the understanding of the effects of climate change and extreme weather on the most populated regions and fastest moving economies in the world. Besides, these volumes also highlight original papers from many prestigious research institutions which are conducting cutting-edge studies in atmospheric physics, hydrogical science and water resource, ocean science and coastal study, planetary exploration and solar system science, seismology, tsunamis, upper atmospheric physics and space science.
Download or read book Evaluating Atlantic Tropical Cyclone Track Error Distributions for Use in Probabilistic Forecasts of Wind Distribution written by Jay M. Neese and published by . This book was released on 2010 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis investigates whether the National Hurricane Center (NHC) operational product for producing probabilistic forecasts of tropical cyclone (TC) wind distributions could be further improved by examining the distributions of track errors it draws upon to calculate probabilities. The track spread/skill relationship for several global ensemble prediction system forecasts is examined as a condition for a description of a full probability distribution function. The 2007, 2008, and 2009 NHC official track forecasts are compared to the ensemble prediction system model along-, cross-, and forecast-track errors. Significant differences in statistical properties were then identified among the groups to determine whether conditioning based on geographic location was warranted. Examination of each regional distribution interval suggests that differences in distributions existed for along-track and cross-track errors. Because errors for ensemble mean and deterministic forecasts typically have larger mean errors and larger variance than official forecast errors, it is unlikely that independent error distributions based on these models would refine the PDFs used in the probabilistic model. However, this should be tested with a sensitivity analysis and verified with the probability swath. Overall, conditional formatting suggests that the NHC probability product may be improved if the Monte Carlo (MC) model would draw from refined distributions of track errors based on TC location.
Download or read book Quantifying the Evolution of GFS and GEFS Mean Tropical Cyclone Track Error and the Synoptic Environments in Which Large Forecast Errors Occur written by Kelly A. Novak and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past few decades, numerical weather prediction (NWP) models (and by extension human forecasts) have evolved markedly due to better meteorological understanding, improved observations, data assimilation, physics parameterization, and increased model resolution (Simmons and Hollingsworth 2001, Elsberry 2013, Landsea and Cangialosi 2018). This includes operational modeling of tropical cyclones (TCs), which were poorly resolved in the mid-1990's but are currently well-resolved in mesoscale models and even some global models. Despite these improvements, there are still cases of large model forecast error and ensemble disagreement (e.g. Sandy 2012, Joaquin 2015, Matthew 2016, Florence 2018). It is important to know if these model improvements are coincident with less frequent poor TC model forecasts over time. In other words, are large model forecast error events becoming less frequent as models have improved? Identification of recurring synoptic environments in which these poor model forecasts occur is also important not only from a meteorological understanding point of view, but also to aid the forecasters to identify in advance of such forecast meteorological setups.Accordingly, the focus of this study is to evaluate how the National Centers for Environmental Prediction's (NCEP's) Global Forecast System (GFS) and Global Ensemble Forecast System ensemble mean (GEFSM) have improved with respect to TC track forecasting over the past two decades, and quantify whether the frequency of truly poor forecasts (e.g. 90th percentile track error) has changed over that period of time. Using the National Hurricane Center's (NHC's) archived model run (advisory files) and verified data (best track files) for the years 2005 through 2020, track errors for the GFS and GEFSM were calculated and statistically analyzed. From those statistics, all forecasts with track error at or above the 90th percentile were identified and the climatology of those forecasts over the years was developed. A comparison between the GFS and GEFSM was also conducted to further evaluate the evolution of TC forecast error over time given the improvements to the GEFS have not been coincident with the GFS. Lastly, spatiotemporal patterns of both track error and synoptic-scale setups common to those cases of poor model performance were identified and subjectively evaluated. This analysis found there was no statistically significant trend in the frequency of these poor GFS track forecasts between 2005 and 2020. However, there was a statistically significant trend in the frequency of poor GEFSM track forecasts. Across the 16 seasons, when the monthly distribution of the worst 10% of track forecasts was normalized by the monthly distribution of all forecasts made (id est, removing the seasonal cycle), there was not a particular month during which significantly more poor GFS or GEFSM track forecasts occurred. A comparison between the average track error of the GFS and GEFSM showed that on average there was smaller GFS mean track error through 72-hour forecasts. Beyond 78 hours, the GEFSM on average outperformed (had smaller track error) than the GFS. Geographically, both models produced poor forecasts for storms in the same month and general basin location. When analyzing the cases in which one of the models, rather than both, produced inaccurate track forecasts, it was found that a considerably large number of poor forecasts were made in the area between 20°N and 24.9°N, 65°W and 69.9°W by either one of the models, a region of the Atlantic basin in which many TCs recurve as the mean flow changes and vertical shear increases. Finally, the synoptic environments in which these poor forecasts occurred were evaluated. Patterns in the orientations of the forecast and observed tracks in the 90th percentile of track error were analyzed and grouped into four categories: vertical ladder, horizontal ladder, funnel, and timing error. In addition, synoptic-scale features potentially related to these large error patterns, such as the subtropical high and the presence of other TCs, were analyzed.
Download or read book Evaluating Atlantic Tropical Cyclone Track Error Distributions Based on Forecast Confidence written by and published by . This book was released on 2006 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new Tropical Cyclone (TC) surface wind speed probability product from the National Hurricane Center (NHC) takes into account uncertainty in track, maximum wind speed, and wind radii. A Monte Carlo (MC) model is used that draws from probability distributions based on historic track errors. In this thesis, distributions of forecast track errors conditioned on forecast confidence are examined to determine if significant differences exist in distribution characteristics. Two predictors are used to define forecast confidence: the Goerss Predicted Consensus Error (GPCE) and the Global Forecast System (GFS) ensemble spread. The distributions of total-, along-, and crosstrack errors from NHC official forecasts are defined for low, average, and high forecast confidence. Also, distributions of the GFS ensemble mean total-track errors are defined based on similar confidence levels. Standard hypothesis testing methods are used to examine distribution characteristics. Using the GPCE values, significant differences in nearly all track error distributions existed for each level of forecast confidence. The GFS ensemble spread did not provide a basis for statistically different distributions. These results suggest that the NHC probability model would likely be improved if the MC model would draw from distributions of track errors based on the GPCE measures of forecast confidence.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Global Perspectives On Tropical Cyclones From Science To Mitigation written by Johnny C L Chan and published by World Scientific. This book was released on 2010-04-30 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a completely rewritten, updated and expanded new edition of the original Global Perspectives on Tropical Cyclones published in 1995. It presents a comprehensive review of the state of science and forecasting of tropical cyclones together with the application of this science to disaster mitigation, hence the tag: From Science to Mitigation.Since the previous volume, enormous progress in understanding tropical cyclones has been achieved. These advances range from the theoretical through to ever more sophisticated computer modeling, all underpinned by a vast and growing range of observations from airborne, space and ocean observation platforms. The growth in observational capability is reflected by the inclusion of three new chapters on this topic. The chapter on the effects of climate change on tropical cyclone activity is also new, and appropriate given the recent intense debate on this issue. The advances in the understanding of tropical cyclones which have led to significant improvements in forecasting track, intensity, rainfall and storm surge, are reviewed in detail over three chapters. For the first time, a chapter on seasonal prediction is included. The book concludes with an important chapter on disaster mitigation, which is timely given the enormous loss of life in recent tropical cyclone disasters.World Scientific Series on Asia-Pacific Weather and Climate is indexed in SCOPUS.
Download or read book Advanced Numerical Modeling and Data Assimilation Techniques for Tropical Cyclone Predictions written by U.C. Mohanty and published by Springer. This book was released on 2016-11-21 with total page 762 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals primarily with monitoring, prediction and understanding of Tropical Cyclones (TCs). It was envisioned to serve as a teaching and reference resource at universities and academic institutions for researchers and post-graduate students. It has been designed to provide a broad outlook on recent advances in observations, assimilation and modeling of TCs with detailed and advanced information on genesis, intensification, movement and storm surge prediction. Specifically, it focuses on (i) state-of-the-art observations for advancing TC research, (ii) advances in numerical weather prediction for TCs, (iii) advanced assimilation and vortex initialization techniques, (iv) ocean coupling, (v) current capabilities to predict TCs, and (vi) advanced research in physical and dynamical processes in TCs. The chapters in the book are authored by leading international experts from academic, research and operational environments. The book is also expected to stimulate critical thinking for cyclone forecasters and researchers, managers, policy makers, and graduate and post-graduate students to carry out future research in the field of TCs.
Download or read book Masters Theses in the Pure and Applied Sciences written by Wade H. Shafer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Oata Analysis and Synthesis (CINOAS) * at Purdue. University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna tional publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 33 (thesis year 1988) a total of 13,273 theses titles from 23 Canadian and 1 85 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 33 reports theses submitted in 1988, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.
Download or read book Air University Abstracts of Research Reports written by and published by . This book was released on 1986 with total page 932 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Weather Review written by and published by . This book was released on 1993 with total page 1084 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characteristic Errors in 120 H Tropical Cyclone Track Forecasts in the Western North Pacific written by and published by . This book was released on 2005 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: All large (>400 n mi at 96 h,>500 n mi at 120 h) Navy Operational Global Atmospheric Prediction System (NOGAPS) and U.S. Navy version of the Geophysical Fluid Dynamics Laboratory Model (GFDN) tropical cyclone track forecast errors in the western North Pacific during the 2004 typhoon season are examined. Responsible error mechanisms are described by conceptual models that are related to known tropical cyclone motion processes being misrepresented in the dynamical models. Of the 162 (135) cases of large NOGAPS (GFDN) forecast errors, 39 were due to tropical influences with excessive direct cyclone - tropics (E-DCI) interaction occurring most frequently. For the 217 large-error cases due to midlatitude influences, the most frequent error mechanisms were E-DCI (midlatitude), excessive response to vertical wind shear, excessive midlatitude cyclogenesis (E-MCG), insufficient midlatitude cyclogenesis (I-MCG), excessive midlatitude cyclolysis (E-MCL) and excessive midlatitude anticyclogenesis (E-MAG), which accounted for 68% of all large errors occurring in both NOGAPS and GFDN. Characteristics and symptoms of the erroneous forecast tracks and model fields are documented and illustrative case studies are presented. Proper identification and removal of the track forecast displaying an error mechanism could form a selective consensus that will be more accurate than a non-selective consensus.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2006 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Statistical Model for the Prediction of Western North Pacific Tropical Cyclone Motion WPCLPR written by Xu Yiming and published by . This book was released on 1985 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hurricane written by Robert Simpson and published by American Geophysical Union. This book was released on 2003 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is based upon presentations at an historical symposium on hurricanes convened by the American Geophysical Union at its Fall meeting in San Francisco, December 16, 2000".
Download or read book Hurricane and Tropical Cumulus Report written by and published by . This book was released on 1978 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
