Download or read book Extratropical Transition of Western North Pacific Tropical Cyclones written by Peter M. Klein and published by . This book was released on 1997-09-01 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extratropical transition (ET) of a tropical cyclone (TC) often results in a mid-latitude storm that threatens maritime and coastal interests. Cases of ET between 1 July through 31 October during 1994-1996 are reviewed using Navy Operational Global Atmospheric Prediction System (NOGAPS) analyses and hourly geostationary satellite imagery. Current conceptual models are found to be inadequate to explain the physical processes in ET. ET is redefined to have two stages: transformation, where the TC is transformed from a warm-core vortex into a baroclinic, cold-core extratropical cyclone, and re- intensification, where the transformed TC either deepens or dissipates, depending on the existence of upper4ropospheric support for extratropical cyclogenesis. ET is further defined in terms of two characteristic mid-latitude synoptic patterns: meridional, in which the cyclones have meridional tracks and tend to re-intensify less vigorously than zonal, which have zonal tracks and may deepen explosively. Review of NOGAPS 5OO-mb anomaly correlation scores in 1996 demonstrated that ET may be associated with significant NOGAPS errors. Sea-level pressure forecasts during ET events involving a merger tend to be too deep. In ET cases of rapidly deepening storms, NOGAPS tends to overforecast their intensity during transformation, and then underforecast during re- intensification. Rules of thumb are provided to assist forecasters in improving predictions of the track and intensity of storms undergoing ET.
Download or read book The Extratropical Transition of Tropical Cyclones written by and published by . This book was released on 2003 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The extratropical transition (ET) of tropical cyclones can sometimes result in rapid changes in the structure and intensity of the tropical cyclone. In particular, the second stage of ET can result in very different results from complete dissipation to rapid intensification into an intense midlatitude cyclone. Whether the tropical cyclone dissipates or reintensifies appears to be strongly dependent on the details of the midlatitude circulation. At the heart of the forecast problem is a lack of knowledge of the fundamental physical changes occurring during ET. Results are presented that show that the details of the midlatitude circulation are probably less important than the basic midlatitude structure for reintensification. Simulations presented here show that variations in the strength of the midlatitude upper-level trough have little impact on the subsequent reintensification of the tropical cyclone. Rather, it is more likely the energy of the background environmental state, and the phasing between the trough and TC that ultimately determine the intensity to which the cyclone can reintensify.
Download or read book The Extratropical Transition of Tropical Cyclones written by Melanie Bieli and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The model, a logistic regression with elastic net regularization, was developed with a focus on predictive performance as well as physical interpretability and thus resides at the interface between machine learning and traditional statistics. It uses eight predictors that characterize the storm and its environment, the most important ones being latitude and sea surface temperature. The model is shown to have skill in forecasting ET at lead times up to two days, and it can predict the phase evolution of storms that undergo ET as well as of storms that remain tropical throughout their lifetimes. When used as an instantaneous diagnostic of a storm's tropical/extratropical status, the model performs about as well as the CPS in the western North Pacific and better than the CPS in the North Atlantic, and it predicts the timings of the transitions better than the CPS in both basins. The model can be integrated into statistical tropical cyclone risk models, or may be applied to provide baseline guidance for operational forecasts.
Download or read book The Extratropical Transition of North Atlantic Tropical Cyclones in a Changing Climate written by Chunyong Jung and published by . This book was released on 2020 with total page 148 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 Climate Change Effects on the Extratropical Transition of Tropical Cyclones in High Resolution Global Simulations written by Allison Claire Michaelis and published by . This book was released on 2019 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Global Perspectives on Tropical Cyclones written by Johnny C. L. Chan and published by World Scientific. This book was released on 2010 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pt. I. Theory of tropical cyclones. ch. 1. Tropical cyclone structure and dynamics / Jeffrey D. Kepert. ch. 2. Tropical cyclone formation / Kevin J. Tory and William M. Frank. ch. 3. Air-sea interactions in tropical cyclones / Lynn K. Shay. ch. 4. Movement of tropical cyclones / Johnny C.L. Chan. ch. 5. The extratropical transition of tropical cyclones : structural characteristics, downstream impacts, and forecast challenges / Patrick A. Harr -- pt. II. Observations of tropical cyclones. ch. 6. Observing and analyzing the near-surface wind field in tropical cyclones / Mark D. Powell. ch. 7. Satellite observations of tropical cyclones / Christopher Velden and Jeffrey Hawkins. ch. 8. Aircraft observations of tropical cyclones / Sim D. Aberson [und weitere] -- pt. III. Climate variations of tropical cyclone activity. ch. 9. Tropical cyclones and climate change : a review / Thomas Knutson, Chris Landsea and Kerry Emanuel -- pt. IV. Forecasting of tropical cyclones. ch. 10. Track and structure forecasts of tropical cyclones / Julian Heming and Jim Goerss. ch. 11. The influence of natural climate variability on tropical cyclones, and seasonal forecasts of tropical cyclone activity / Suzana J. Camargo [und weitere] -- pt. V. Hydrological aspects of tropical cyclones. ch. 12. Storm surge modeling and applications in coastal areas / Shishir K. Dube [und weitere] -- pt. VI. Societal impacts of tropical cyclones. ch. 13. Disaster mitigation and societal impacts / David King, Jim Davidson and Linda Anderson-Berry
Download or read book Diagnosing the Downstream Impact of Extratropical Transition Using Multimodel Operational Ensemble Prediction Systems written by Julia Henriette Keller and published by KIT Scientific Publishing. This book was released on 2014-10-16 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study examines the predictability during the extratropical transition (ET) of tropical cyclones using the THORPEX Interactive Grand Global Ensemble (TIGGE), a multimodel ensemble prediction system (EPS). It is shown that TIGGE exhibits more possible development scenarios than a single EPS. By analysing the eddy kinetic energy budget of forecast scenarios for two ET cases, extracted from an EPS, the impact of the transitioning tropical cyclones on the midlatitude flow is studied in detail.
Download or read book Tropical Cyclone and Mid Latitude Characteristics and Physical Mechanisms Contributing to Extratropical Transition in the Western North Pacific written by Peter M. Klein and published by . This book was released on 2000-12-01 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study of extratropical transition (ET) of tropical cyclones (TCs) in the western North Pacific examines 30 cases during 1 June through 31 October 1994-98 using Navy analyses, plus geostationary satellite visible, infrared, water vapor, and microwave imagery. Based on the similarity of all 30 ET cases in satellite imagery, a three-dimensional conceptual model of the transformation stage of ET is proposed to describe how these ET cases evolve into an incipient, baroclinic cyclone. A climatology of ET during the period studied is presented, and three levels of re-intensification (little, moderate, and deep) are defined based on storm intensity at the end of ET. The re- intensification stage in nine cases is studied via Navy Coupled Ocean-Atmosphere Mesoscale Prediction System (COAMPS) control forecasts, simulations with the initial TC vortex removed, and simulations in which the initial TC vortex is displaced. These COAMPS simulations demonstrate that deep or moderate re- intensification depends on phasing of the poleward translating TC remnants with a critical region in which cyclogenesis is favored in the mid-latitude circulation. The mid-latitude circulation and TC contributions to the re- intensification stage are identified via superposition with the critical region and modification of its location and diagnostic values, respectively, and the combination of these contributions determines the final storm intensity at the end of ET.
Download or read book Predictability Associated with the Downstream Impact of the Extratropical Transition of Tropical Cyclones written by and published by . This book was released on 2005 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since an extratropical transition (ET) of a decaying tropical cyclone (TC) often results in a fast-moving, rapidly developing extratropical cyclone and amplification of synoptic-scale systems far downstream, proper forecasting of ET events is critical to forecast accuracy over large ocean regions. Past studies have linked forecast accuracy to the phasing of a decaying TC with favorable midlatitudes conditions. Because ET events are sensitive to the analyzed initial conditions, this phasing is examined using 11 member ensemble predictions available four times daily from the National Centers for Environmental Prediction, which were combined into a single 44 member ensemble based on a common forecast verification time. Recurring ET patterns within the 44 member ensemble were objectively identified using a combination of EOF and cluster analysis. Ensemble spread first appears near the point where the TC moves into the midlatitudes and then propagates downstream. Although ensemble spread in the forecast fields was large at extended forecast intervals, the ensemble spread, and the number of ET patterns identified in successive EPS predictions, decreased as the ET process became better defined. Within 48 hours of the ET event, the ensemble prediction system properly identified the ET pattern with a minimum ensemble spread. Similar to Klein et al. (2002), the shifts in the initial position of the TC and the subsequent dynamical coupling can explain differences between weak and strong ET reintensifications.
Download or read book The Extratropical Transition of Atlantic Tropical Cyclones written by Robert Edward Hart and published by . This book was released on 2001 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Potential Vorticity Perspective on the Extratropical Transition of Tropical Cyclones written by Anna Agust©Ư-Panareda and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Extratropical transitions (ET) of tropical cyclones are common in all ocean basins where tropical cyclones recurve polewards. They can result in the development of large and deep extratropical cyclones. Two detailed case studies are presented: hurricane Irene and hurricane Lili which resulted in a reintensification with different deepening rates - two potential vorticity-based conceptual models have been devised from these results - abstract.
Download or read book Downstream Impacts Due to the Extratropical Transition of Tropical Cyclones Over the Western North Pacific written by and published by . This book was released on 2007 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analysis of the eddy kinetic energy budget for four cases of extratropical transition (ET) with North Pacific tropical cyclones (TCs) is conducted. The cases compare varying ET and midlatitude flow characteristics. Each case was examined to determine the impacts of eddy kinetic energy generation and/or transfer on downstream development in the midlatitude circulation. Typhoon Tokage (October 2004) was a large TC that moved into a high-amplitude midlatitude circulation. Energetics analysis revealed that the ET of Tokage influenced the development of a deep trough over the central North Pacific before Tokage moved poleward and weakened transfer. Typhoon Banyan (July 2005) was a mid-summer case that influenced downstream development ultimately over the Aleutian Islands. Typhoon Guchol (August 2005) was a small TC that was dominated by midlatitude flow. However, the merger of Guchol with a midlatitude trough enabled development downstream of a separate trough. Typhoon Nabi was an intense TC that injected significant EKE into the midlatitude circulation during ET. Through downstream development, Nabi changed a zonal pattern over the North Pacific into an amplified pattern. These cases indicate that the ET process over the western North Pacific impacts the midlatitude circulation across the entire North Pacific basin.
Download or read book Impacts of Extratropical Transition on Tropical Cyclone Tornado Occurrence written by Kayla Wheeler and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Extratropical Transitions in the North Atlantic with Special Reference to Hurricane Igor written by Athena Masson and published by . This book was released on 2013 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Predictability of Extratropical Transition and of Its Impact on the Downstream Flow written by and published by . This book was released on 2008 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this project we investigated the basic mechanisms that determine the predictability of tropical cyclones undergoing extratropical transition (ET) and of their impact on the downstream flow. The analysis of ensemble forecasts for five ET cases showed that uncertainty is associated with the location and amplitude of a characteristic upper-level trough-ridge-trough pattern consisting of the trough that interacts with the tropical cyclone, a ridge directly downstream and a second trough downstream of the ridge. Experiments for Typhoon Tokage (2004) with the ensemble prediction system of the European Centre for Medium Range Weather Forecasts showed that targeted perturbations led to increased spread around and shortly after ET time whereas the spread due to stochastic physics increased at a later time as the influence of the targeted perturbations decreased. Idealized modelling combined with potential vorticity inversion was used to quantify the mechanisms responsible for this variability. Furthermore, dropsonde data in the vicinity of tropical cyclones were shown to reduce the medium-range forecast error for the downstream flow.
Download or read book A Projection Pursuit Application to Predict Extratropical Transition of Tropical Cyclones written by Oguz Demirci and published by . This book was released on 2006 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this research, a multistage projection pursuit technique is presented that is used to predict the end results of the extratropical transition of the tropical cyclones. The technique extracts the spatial features relevant to extratropical transition that can be obtained from NOGAPS analyses and remotely sensed data. Various atmospheric variables at different levels of the atmosphere are used in the spatial and spatiotemporal techniques. The technique is tested in a forecasting environment on tropical cyclones from recent years, and results show prediction comparable to a global numerical weather prediction system with 75% prediction and 30% false alarm rate. The system is further developed to have utility for forecasting by examining ways to utilize forecast fields in various stages of the technique. This allows the prediction to occur ahead of time. Trials in this "forecast mode" indicate results that are slightly less accurate than those obtained using analysis fields during the development phase. However, the results are promising and further possible improvements are discussed.
