Joint Typhoon Warning Center

The Great Hungarian Plain was a crossroads of cultural transformations that have shaped European prehistory. Here we analyse a 5,000-year transect of human genomes, sampled from petrous bones giving consistently excellent endogenous DNA yields, from 13 Hungarian Neolithic, Copper, Bronze and Iron Age burials including two to high (~22 × ) and seven to ~1 × coverage, to investigate the impact of these on Europe's genetic landscape. These data suggest genomic shifts with the advent of the Neolithic, Bronze and Iron Ages, with interleaved periods of genome stability. The earliest Neolithic context genome shows a European hunter-gatherer genetic signature and a restricted ancestral population size, suggesting direct contact between cultures after the arrival of the first farmers into Europe. The latest, Iron Age, sample reveals an eastern genomic influence concordant with introduced Steppe burial rites. We observe transition towards lighter pigmentation and surprisingly, no Neolithic presence of lactase persistence.

Determining the proper relationship between the minimum sea level pressures and maximum sustained winds in tropical cyclones has been a long standing problem. The major obstacle has been the lack of sufficient ground truth, i.e., actual measurements of maximum wind speeds in tropical cyclones with a wide range of central pressures. In this study, 26 years of maximum wind measurements made at coastal and inland stations in the western North Pacific were collected and analyzed. Because of problems in measuring and interpreting sustained surface wind speeds, only recorded peak gusts values were used. These peak gusts values were reduced to a standard anemometer level of 10 meters using a power law relationship and then coverted to one-minute sustained wind speeds using gust factors representative of an over water environment. The sample was restricted to those cases in which it was reasonably certain that the station experienced the cyclone's maximum winds during its passage. The resulting equation V sub m = 6.7 (1010-P sub c) 0.644 where P sub c is the minimum sea level pressure (mb) and V sub m is the maximum sustained wind speed (knots), indicates maximum wind speeds that are significantly lower than many previous studies. (Author)

Abstract. Much research and speculation exists about the meteorological and climatological impacts of biomass burning in the Maritime Continent (MC) of Indonesia and Malaysia, particularly during El Nino events. However, the MC hosts some of the world's most complicated meteorology, and we wish to understand how tropical phenomena at a range of scales influence observed burning activity. Using Moderate Resolution Imaging Spectroradiometer (MODIS) derived active fire hotspot patterns coupled with aerosol data assimilation products, satellite based precipitation, and meteorological indices, the meteorological context of observed fire prevalence and smoke optical depth in the MC are examined. Relationships of burning and smoke transport to such meteorological and climatic factors as the interannual El Nino-Southern Oscillation (ENSO), El Nino Modoki, Indian Ocean Dipole (IOD), the seasonal migration of the Intertropical Convergence Zone, the 30–90 day Madden Julian Oscillation (MJO), tropical waves, tropical cyclone activity, and diurnal convection were investigated. A conceptual model of how all of the differing meteorological scales affect fire activity is presented. Each island and its internal geography have different sensitivities to these factors which are likely relatable to precipitation patterns and land use practices. At the broadest scales as previously reported, we corroborate ENSO is indeed the largest factor. However, burning is also enhanced by periods of El Nino Modoki. Conversely, IOD influences are unclear. While interannual phenomena correlate to total seasonal burning, the MJO largely controls when visible burning occurs. High frequency phenomena which are poorly constrained in models such as diurnal convection and tropical cyclone activity also have an impact which cannot be ignored. Finally, we emphasize that these phenomena not only influence burning, but also the observability of burning, further complicating our ability to assign reasonable emissions.

Ancestry assessments using cranial morphoscopic traits currently rely on subjective trait lists and observer experience rather than empirical support. The trait list approach, which is untested, unverified, and in many respects unrefined, is relied upon because of tradition and subjective experience. Our objective was to examine the utility of frequently cited morphoscopic traits and to explore eleven appropriate and novel methods for classifying an unknown cranium into one of several reference groups. Based on these results, artificial neural networks (aNNs), OSSA, support vector machines, and random forest models showed mean classification accuracies of at least 85%. The aNNs had the highest overall classification rate (87.8%), and random forests show the smallest difference between the highest (90.4%) and lowest (76.5%) classification accuracies. The results of this research demonstrate that morphoscopic traits can be successfully used to assess ancestry without relying only on the experience of the observer.

The cylindrical inclusion (CI) protein of potyviruses is involved in virus replication and cell-to-cell movement. These two processes should rely on multiple plant-virus interactions; however, little is known about the host factors that are involved in, or that may interfere with, CI functions. By using a yeast two-hybrid system, the CI protein from Plum pox virus (PPV) was found to interact with the photosystem I PSI-K protein, the product of the gene psaK, of Nicotiana benthamiana. Coexpression of PPV CI was shown to cause a decrease in the accumulation level of PSI-K transiently expressed in N. benthamiana leaves. To test the biological relevance of this interaction, we have analyzed the infection of PPV in N. benthamiana plants in which psaK gene expression has been silenced by RNA interference, as well as in Arabidopsis thaliana psaK knockout plants. Our results show that downregulation of the psaK gene leads to higher PPV accumulation, suggesting a role for the CI-PSI-K interaction in PPV infection.

This article provides a review of tropical cyclone (TC) surface wind estimation from an operational forecasting perspective. First, we provide a summary of operational forecast center practices and historical databases. Next, we discuss current and emerging objective estimates of TC surface winds, including algorithms, archive datasets, and individual algorithm strengths and weaknesses as applied to operational TC surface wind forecast parameters. Our review leads to recommendations about required surface coverage – an area covering at least 1100 km from center of TC at a 2-km resolution in the inner-core, and at a frequency of at least once every 6 h. This is enough coverage to support a complete analysis of the TC surface wind field from center to the extent of the 34-kt (17 m s−1) winds at 6-h intervals. We also suggest future designs of TC surface wind capabilities include funding to ensure near real-time data delivery to operators so that operational evaluation and use are feasible within proposed budgets. Finally, we suggest that users of archived operational wind radii datasets contact operational organizations to ensure these datasets are appropriate for their needs as the datasets vary in quality through time and space, even from a single organisation.

As the impact of coronavirus disease 2019 (COVID-19) continues to permeate throughout global healthcare systems, the lives of staff physicians, medical and surgical residents, medical students, and other allied healthcare workers are in constant flux. Priorities for healthcare workers currently center around providing effective patient care, ensuring adequate personal protective equipment, ventilator supply, and hospital capacity. In an effort to increase hospital capacity to account for the surge of critically ill COVID-19 patients and to protect healthcare workers, the American College of Surgeons recommended that all hospitals, “review all scheduled elective procedures with a plan to minimize, postpone, or cancel electively scheduled operations, endoscopies, or other invasive procedures” until further notice.1 The American College of Surgeons recommendation has undoubtedly left surgical residents and trainees in a precarious position. With a dramatic reduction in operative exposure, and in some cases, with a mandate to remain at home, how will surgical trainees maintain their surgical skill and intraoperative knowledge? Fortunately, given significant technological advancements over the past several decades, there remain a number of options for the maintenance of intraoperative knowledge beyond textbook-learning that are easily accessible from home. Computer- and phone-based technologies provide access to intraoperative video recordings, virtual reality operating room simulations, and other interactive surgical platforms. Such applications are widely available and have the potential to satisfy and supplement the learning needs of surgical trainees as defined by surgical education governing bodies.2 Moreover, surgical simulation has the potential to increase objective technical proficiency in the operating room, decrease intraoperative errors, and decrease operative time.3 The aim of the present article is to provide an overview of the available computer- and phone-based platforms accessible at home for surgical trainees who currently have limited surgical exposure given the ongoing COVID-19 pandemic. Such a review may allow surgical trainees and surgical education governing bodies to initiate and create at-home surgical curricula during the COVID-19 pandemic. COMPUTER-BASED PLATFORMS Exponential growth of computer processing power over recent decades has fueled a parallel expansion of computer-based surgical platforms. Currently, over 20 computer-based platforms, ranging over 9 surgical specialties, are available on the internet and are accessible from home. Fifteen computer-based platforms are freely accessible, 1 platform (Incision Academy) is offering a 4-week free trial during the COVID-19 pandemic, and 7 platforms require paid accounts. Two paid platforms present material pertaining to all surgical specialties. The Surgical Council on Resident Education Portal provides an online surgical curriculum with access to over 800 modules, 2,000 multiple choice questions, and 220 narrated intraoperative videos. Approximately 95% of American General Surgery residency programs subscribe.4 It has been demonstrated that residents with an active subscription to the Surgical Council on Resident Education Portal score higher on their American Board of Surgery Qualifying Examination.5 The Journal of Medical Insight is a peer-reviewed surgical video journal that offers annotated intraoperative videos along with supporting primary literature, organized neatly into “chapters.” Each chapter pertains to a specific step of the selected procedure, and offers an opportunity for self-assessment. Access to this platform costs $50 per month or $500 per year for surgical residents. Two platforms focus solely on General Surgery and 6 have content pertaining mostly to General Surgery whereas also having additional modules focused on other surgical specialties. Incision Academy is a European-based online platform that presents live intraoperative video. It details the steps of a given operation, provides primary literature evidence, allows for interactive anatomy learning relevant to the operation, and has a section for self-assessment. They have released a free 4-week trial in light of the COVID-19 pandemic. WebSurg is an online platform that publishes multimedia General Surgery, and Gynecology, content monthly. It is produced by the Institute for Research into Cancer of the Digestive System (France) and is supported by Medtronic and Karl Storz. Over 2000 sequenced and subtitled intraoperative videos in 7 languages are currently available. This platform also offers free live webinars and conference broadcasts. Users must register a free online account for full access. Teach Me Surgery has a large General Surgery section and sections available for other surgical specialties. This is a free platform that organizes over 400 peer-reviewed articles, has over 1000 interactive clinical images, and allows for self-assessment. Similarly, Surgery Squad caters to General Surgery, Ophthalmology, and Obstetrical procedures. It is an interactive, virtual reality platform that allows the user to progress through the key steps of an operation. Five platforms focus primarily on Otorhinolaryngology – Head & Neck Surgery. e-lefENT is a United Kingdom-based, interactive, and self-assessment driven online platform that is mapped to fit the Intercollegiate Surgical Curriculum Programme. It is funded by Medtronic and requires a paid subscription. Headmirror is an online surgical atlas with live, narrated intraoperative videos spanning numerous subspecialties (ie, facial plastic surgery, head and neck surgery, laryngology, otology and neurotology, rhinology and sinus surgery, pediatric otolaryngology). It is free platform maintained by the Otorhinolaryngology – Head & Neck Surgery department at The Mayo Clinic. There are 3 ophthalmology-specific platforms available, 2 of which are free to all users. Eye Tube is an online platform that allows users to view fully narrated live intraoperative videos of ophthalmology procedures (ie, cataract, glaucoma, oculoplastics). It offers a new 3-dimensional channel for intraoperative viewing. eIntegrity is a paid platform sponsored by the National Health Services and the Royal College of Ophthalmologists. Three orthopedic-specific computer-based platforms are available from home. Ortho Oracle is a surgical atlas that contains live, intraoperative videos for the following orthopedic subspecialties: shoulder and elbow, hand and wrist, spine, hip, knee, foot and ankle, and oncology. It is a United Kingdom-based platform that costs 7 euros per month for a full subscription. The full version allows you to take notes on their platform while watching videos and uses International Business Machines Corporation Watson to deliver relevant primary literature. AO Surgery Reference is an online repository for the management of fractures at any anatomic location. It provides free access to interactive modules that progress through key steps (with picture instructions) of preoperative, intraoperative, and postoperative fracture management. Fundamental Surgery requires access to HapticVR technology. Two platforms have been validated in peer-review publications. Simulation General and Thoracic Surgery increased resident knowledge base in thoracic surgery procedures (pre-test: 42.5% vs post-test: 78.6%, P < 0.0001) and enhanced confidence when preparing for live thoracic procedures.6 It is a free platform affiliated with the University of Virginia that incorporates ex-vivo videos aimed at highlighting essential steps and equipment for thoracic operations (eg, Nissen Fundoplication, Repair of Acute Esophageal Perforation, Left Postero-Lateral Thoracotomy). CyberSight is a free online surgical learning platform that includes modules focused on the following topics: cataract surgery, cornea anatomy, glaucoma, pediatric ophthalmologic disease, and strabismus. These courses were developed and delivered by Ophthalmologists from around the world, including UC Davis Eye center, New England College of Optometry, and Middle East Africa Council of Ophthalmology. This platform also includes an online mentoring service that, along with the modules, have been shown to be a viable method for delivering ophthalmology expertise globally.7 Other available platforms include VideoUrology, Toronto Video Atlas of Surgery, Decker Med (paid subscription required), Wise-MD, and Multi-media Manual of Cardio-thoracic Surgery. PHONE BASED PROGRAMS In addition to web-based modalities for surgical simulation, there are educational phone-based platforms. Touch Surgery is a free-trial phone surgical simulation application that includes 12 different surgical specialties (Cardiothoracic Surgery; General Surgery; Global Surgery; Neurosurgery; Obstetrics and Gynecology; Ophthalmology; Oro-maxillofacial Surgery; Orthopedics and Trauma; Otolaryngology Head and Neck Surgery; Plastic, Reconstructive and Aesthetic Surgery; Urology and Vascular Surgery) with over 200 procedures for surgical simulation. Furthermore, there is a self-assessment component to ensure material consolidation. Touch Surgery has been validated by 19 independent peer-reviewed publications. For example, Touch Surgery laparoscopy and intramedullary femoral nail simulations were able to significantly distinguish between expert surgeons and novices (P < 0.001, P < 0.001).8,9 Additionally, studies have reported that users find the surgical simulations to be realistic.8,9 Level Ex developed 4 free interactive animated phone applications entitled Cardio Ex, Pulm Ex, Gastro Ex, and Airway Ex. Although Cardio Ex, Pulm Ex, and Airway Ex focus on medical/anesthesiology simulation, Gastro Ex involves colorectal surgery simulation. Gastro Ex provides users with feedback on accuracy and speed during endoscope, biopsy and cautery tasks. No peer-reviewed publications exist validating Level Ex applications. Two free interactive, video-based surgical simulation applications from Belgium were published in 2016–2017, including My Virtual Surgery and CABG - OPCAB Surgery Training. These applications include surgical simulation from Cardiac Surgery, Vascular Surgery, Plastic Surgery, General Surgery, Obstetrics and Gynecology. All of these applications include opportunities for learner self-assessment. Other surgical simulation phone-based platforms include LapGuru, OrthoGuru, and Ensafe VATS. CONCLUSIONS Amidst the COVID-19 public health crisis, that has infected more than 1 million people in over 180 countries, the educational needs of surgical trainees should not be neglected. Promoting remote learning platforms such as those highlighted in the present review and integrating them into formal curriculum can expand educational opportunities beyond the walls of the hospital. Such measures may mitigate the diminished surgical skill among surgical trainees that is foreseeable in hospitals across the word.

Abstract A relatively simple method to estimate tropical cyclone (TC) wind radii from routinely available information including storm data (location, motion, and intensity) and TC size is introduced. The method is based on a combination of techniques presented in previous works and makes an assumption that TCs are largely symmetric and that asymmetries are based solely on storm motion and location. The method was applied to TC size estimates from two sources: infrared satellite imagery and global model analyses. The validation shows that the methodology is comparable with other objective methods based on the error statistics. The technique has a variety of practical research and operational applications, some of which are also discussed.

Biomechanical testing was performed on 5 cadaveric knees to evaluate the effect of patellofemoral design on shear and compressive force at the patellar component-bone interface. Three patellofemoral designs with identical tibiofemoral articular surfaces were tested. The knees were tested under dynamic loading conditions from 0 degree to 100 degrees flexion. A transducer that measured 3 orthogonal force components was mounted between the patellar component and the patella. The combination of an oval dome patella with a 2-mm deeper trochlear groove and associated increased femoral resection was compared with a biconcave patella with standard trochlea and normal femoral resection. Alignment of the trochlear groove in 7 degrees valgus (anatomic) decreased medial-lateral shear by 10% to symmetric trochlear groove alignment.

A skeletal assessment of ancestry relies on morphoscopic traits and skeletal measurements. Using a sample of American Black (n = 38), American White (n = 39), and Southwest Hispanics (n = 72), the present study investigates whether these data provide similar biological information and combines both data types into a single classification using a random forest model (RFM). Our results indicate that both data types provide similar information concerning the relationships among population groups. Also, by combining both in an RFM, the correct allocation of ancestry for an unknown cranium increases. The distribution of cross-validated grouped cases correctly classified using discriminant analyses and RFMs ranges between 75.4% (discriminant function analysis, morphoscopic data only) and 89.6% (RFM). Unlike the traditional, experience-based approach using morphoscopic traits, the inclusion of both data types in a single analysis is a quantifiable approach accounting for more variation within and between groups, reducing misclassification rates, and capturing aspects of cranial shape, size, and morphology.

ABSTRACT: This review prepared for the fourth International Workshop on Tropical Cyclone Landfall Processes (IWTCLP-4) summarizes the most recent (2015-2017) theoretical and practical knowledge in the field of tropical cyclone (TC) track, intensity, and structure rapid changes at or near landfall. Although the focus of IWTCLP-IV was on landfall, this summary necessarily embraces the characteristics of storms during their course over the ocean prior to and leading up to landfall. In the past few years, extremely valuable observational datasets have been collected for TC forecasting guidance and research studies using both aircraft reconnaissance and new geostationary or low-earth orbiting satellites at high temporal and spatial resolution. Track deflections for systems near complex topography such as that of Taiwan and La Réunion have been further investigated, and advanced numerical models with high spatial resolution necessary to predict the interaction of the TC circulation with steep island topography have been developed. An analog technique has been designed to meet the need for longer range landfall intensity forecast guidance that will provide more time for emergency preparedness. Probabilistic track and intensity forecasts have also been developed to better communicate on forecast uncertainty. Operational practices of several TC forecast centers are described herein and some challenges regarding forecasts and warnings for TCs making landfall are identified. This review concludes with insights from both researchers and forecasters regarding future directions to improve predictions of TC track, intensity, and structure at landfall. Keywords: tropical cyclone, track, intensity, structure, landfall, rapid intensification, rapid changes

This article provides a unique benchmark to integrate and systematically evaluate advanced functionalities of microgrid and downstream device controllers. The article describes Banshee, a real‐life power distribution network. It also details a real‐time controller hardware‐in‐the‐loop (HIL) prototyping platform to test the responses of the controllers and verify decision‐making algorithms. The benchmark aims to address power industry needs for a common basis to integrate and evaluate controllers for the overall microgrid, distributed energy resources (DERs), and protective devices. The test platform will accelerate microgrid deployment, enable standard compliance verification, and further develop and test controllers' functionalities. These contributions will facilitate safe and economical demonstrations of the state‐of‐the‐possible while verifying minimal impact to existing electrical infrastructure. All aspects of the benchmark and platform development including models, configuration files, and documentation are publicly available via the electric power HIL controls collaborative (EPHCC).

Children with chronic hepatitis B (CHB) represent an area of unmet medical need, attributed to increased lifetime risk of CHB sequelae and limited therapeutic options compared with adult CHB patients. The PEG‐B‐ACTIVE (NCT01519960) phase III study evaluated peginterferon (PegIFN) alfa‐2a treatment in children aged 3 to &lt;18 years with CHB. A total of 161 hepatitis B e antigen (HBeAg)‐positive immune‐active patients without advanced fibrosis (AF)/cirrhosis were randomized (2:1) to PegIFN alfa‐2a (Group A, n = 101) or no treatment (Group B, n = 50); patients with AF were assigned to PegIFN alfa‐2a (Group C, n = 10). PegIFN alfa‐2a was administered for 48 weeks by body surface area (BSA) category, based on 180 μg/1.73 m 2 . HBeAg seroconversion rates at 24 weeks posttreatment were significantly higher in Group A (25.7% vs. 6%; P = 0.0043), as were the rates of hepatitis B surface antigen (HBsAg) clearance (8.9% vs. 0%; P = 0.03), hepatitis B virus (HBV) DNA &lt;2,000 IU/mL (28.7% vs. 2.0%; P &lt; 0.001) or undetectable (16.8% vs. 2.0%; P = 0.0069), and alanine aminotransferase (ALT) normalization (51.5% vs. 12%; P &lt; 0.001). Safety, including incidence of ALT flares and neutropenia, was comparable to the established PegIFN alfa‐2a profile in HBV‐infected adults or hepatitis C virus‐infected children. Changes in growth parameters were minimal during treatment and comparable to those in untreated patients. Safety and efficacy outcomes in Group C were in line with Group A. Conclusion: PegIFN alfa‐2a treatment of children in the immune‐active phase of CHB was efficacious and well tolerated, and associated with higher incidence of HBsAg clearance than in adults. This represents an important advance to the treatment options for children with CHB.

Abstract The Joint Typhoon Warning Center’s (JTWC) forecast improvement goals include reducing 34-kt (1 kt = 0.514 m s−1) wind radii forecast errors, so accurate real-time estimates and postseason analysis of the 34-kt wind radii are critical to reaching this goal. Accurate real-time 34-kt wind radii estimates are also critical for decisions regarding base preparedness and asset protection, but still represent a significant operational challenge at JTWC for several reasons. These reasons include a paucity of observations, the timeliness and availability of guidance, a lack of analysis tools, and a perceived shortage of personnel to perform the analysis; however, the number of available objective wind radii estimates is expanding, and the topic of estimating 34-kt wind radii warrants revisiting. In this work an equally weighted mean of real-time 34-kt wind radii objective estimates that provides real-time, routine operational guidance is described. This objective method is also used to retrospectively produce a 2-yr (2014–15) 34-kt wind radii objective analysis, the results of which compare favorably to the postseason National Hurricane Center data (i.e., the best tracks), and a newly created best-track dataset for the western North Pacific seasons. This equally weighted mean, when compared with the individual 34-kt wind radii estimate methods, is shown to have among the lowest mean absolute errors and smallest biases. In an ancillary finding, the western North Pacific basin average 34-kt wind radii calculated from the 2014–15 seasons are estimated to be 134 n mi (1 n mi = 1.852 km), which is larger than the estimates for storms in either the Atlantic (95 n mi) or eastern North Pacific (82 n mi) basins for the same years.

This review summarizes the rapporteur report on tropical cyclone (TC) intensity change from the operational perspective, as presented to the 10th International Workshop on TCs (IWTC-10) held in Bali, Indonesia, from Dec. 5–9, 2022. The accuracy of TC intensity forecasts issued by operational forecast centers depends on three aspects: real-time observations, TC dynamical model forecast guidance, and techniques and methods used by forecasters. The rapporteur report covers the progress made over the past four years (2018–2021) in all three aspects. This review focuses on the progress of dynamical model forecast guidance. The companion paper (Part II) summarizes the advance from operational centers. The dynamical model forecast guidance continues to be the main factor leading to the improvement of operational TC intensity forecasts. Here, we describe recent advances and developments of major operational regional dynamical TC models and their intensity forecast performance, including HWRF, HMON, COAMPS-TC, Met Office Regional Model, CMA-TYM, and newly developed HAFS. The performance of global dynamical models, including NOAA's GFS, Met Office Global Model (MOGM), JMA's GSM, and IFS (ECMWF), has also been improved in recent years due to their increased horizontal and vertical resolution as well as improved data assimilation systems. Recent challenging cases of rapid intensification are presented and discussed.

Abstract This study documents the recent efforts of the hurricane modeling team at the National Centers for Environmental Prediction’s (NCEP) Environmental Modeling Center (EMC) in implementing the operational Hurricane Weather Research and Forecasting Model (HWRF) for real-time tropical cyclone (TC) forecast guidance in the western North Pacific basin (WPAC) from May to December 2012 in support of the operational forecasters at the Joint Typhoon Warning Center (JTWC). Evaluation of model performance for the WPAC in 2012 reveals that the model has promising skill with the 3-, 4-, and 5-day track errors being 125, 220, and 290 nautical miles (n mi; 1 n mi = 1.852 km), respectively. Intensity forecasts also show good performance, with the most significant intensity error reduction achieved during the first 24 h. Stratification of the track and intensity forecast errors based on storm initial intensity reveals that HWRF tends to underestimate storm intensity for weak storms and overestimate storm intensity for strong storms. Further analysis of the horizontal distribution of track and intensity forecast errors over the WPAC suggests that HWRF possesses a systematic negative intensity bias, slower movement, and a rightward bias in the lower latitudes. At higher latitudes near the East China Sea, HWRF shows a positive intensity bias and faster storm movement. This appears to be related to underestimation of the dominant large-scale system associated with the western Pacific subtropical high, which renders weaker steering flows in this basin.

Super Typhoon Tip was an eventful tropical cyclone which developed in the western North Pacific in early, October 1979. Besides establishing the world's record for the lowest minimum sea level pressure ever measured in a tropical cyclone, Tip also possessed the largest surface, circulation pattern ever observed for a tropical cyclone. The development cycle of Super Typhoon Tip from a weak disturbance to a mature typhoon to an extratropical system is discussed in view of the record breaking performance of this typhoon.

The Joint Typhoon Warning Center (JTWC), a specialized component of the Naval Oceanography Command Center, Guam, is the busiest tropical cyclone warning center in the world. Its area of responsibility encompasses four broad oceanic areas of tropical cyclone activity stretching from the international date line to the east coast of Africa, in both hemispheres. Our paper discusses the challenges imposed on the center as a result of its vast multibasin area of responsibility, the products the center produces, its warning philosophy, observational networks, analysis and forecast schemes, and the military aspects of the operation. Because of the multibasin, dual-hemisphere responsibility, there is no off-season. The challenges of information and time management, analysis and forecast improvement, expansion of meteorological understanding, and enhancement of the warning process are discussed. Current methods used to meet these challenges are presented. In addition, the paper gives a brief overview of JTWC's colorful history, with emphasis on the aircraft reconnaissance era and the evolution of satellite reconnaissance. The joint Navy-Air Force Operations Evaulation to assess the impact of the loss of aircraft reconnaissance and the Office of Naval Research Tropical Cyclone Motion-90 Experiment are briefly discussed. Finally, the paper takes a cursory look at JTWC's postanalysis program, which includes the Annual Tropical Cyclone Report; training, qualification, and certification programs; and technique development to improve tropical cyclone analysis and forecasting.

Abstract This study presents evaluation of real-time performance of the National Centers for Environmental Prediction (NCEP) operational Hurricane Weather Research and Forecast (HWRF) modeling system upgraded and implemented in 2013 in the western North Pacific basin (WPAC). Retrospective experiments with the 2013 version of the HWRF Model upgrades for 2012 WPAC tropical cyclones (TCs) show significant forecast improvement compared to the real-time forecasts from the 2012 version of HWRF. Despite a larger number of strong storms in the WPAC during 2013, real-time forecasts from the 2013 HWRF (H213) showed an overall reduction in intensity forecast errors, mostly at the 4–5-day lead times. Verification of the H213’s skill against the climate persistence forecasts shows that although part of such improvements in 2013 is related to the different seasonal characteristics between the years 2012 and 2013, the new model upgrades implemented in 2013 could provide some further improvement that the 2012 version of HWRF could not achieve. Further examination of rapid intensification (RI) events demonstrates noticeable skill of H213 with the probability of detection (POD) index of 0.22 in 2013 compared to 0.09 in 2012, suggesting that H213 starts to show skill in predicting RI events in the WPAC.

Abstract In 2016, the Joint Typhoon Warning Center extended forecasts of gale-force and other wind radii to 5 days. That effort and a thrust to perform postseason analysis of gale-force wind radii for the “best tracks” (the quality controlled and documented tropical cyclone track and intensity estimates released after the season) have prompted requirements for new guidance to address the challenges of both. At the same time, operational tools to estimate and predict wind radii continue to evolve, now forming a quality suite of gale-force wind radii analysis and forecasting tools. This work provides an update to real-time estimates of gale-force wind radii (a mean/consensus of gale-force individual wind radii estimates) that includes objective scatterometer-derived estimates. The work also addresses operational gale-force wind radii forecasting in that it provides an update to a gale-force wind radii forecast consensus, which now includes gale-force wind radii forecast error estimates to accompany the gale-force wind radii forecasts. The gale-force wind radii forecast error estimates are computed using predictors readily available in real time (e.g., consensus spread, initial size, and forecast intensity) so that operational reliability and timeliness can be ensured. These updates were all implemented in operations at the Joint Typhoon Warning Center by January 2018, and more updates should be expected in the coming years as new and improved guidance becomes available.