Edward N. Rappaport

Advances and Challenges at the National Hurricane Center

Abstract The National Hurricane Center issues analyses, forecasts, and warnings over large parts of the North Atlantic and Pacific Oceans, and in support of many nearby countries. Advances in observational capabilities, operational numerical weather prediction, and forecaster tools and support systems over the past 15–20 yr have enabled the center to make more accurate forecasts, extend forecast lead times, and provide new products and services. Important limitations, however, persist. This paper discusses the current workings and state of the nation’s hurricane warning program, and highlights recent improvements and the enabling science and technology. It concludes with a look ahead at opportunities to address challenges.

Loss of Life in the United States Associated with Recent Atlantic Tropical Cyclones

A database was established for the period 1970–99 to assess the threat to life in the contiguous United States and adjacent coastal waters from Atlantic tropical cyclones. Freshwater floods caused more than one-half of the 600 U.S. deaths directly associated with tropical cyclones or their remnants during that 30-year period. More than three-quarters of the victims under age 13 died in rain-induced floods. Most fatalities occurred in inland counties. Storm surge losses were significantly (but perhaps only temporarily) less than in previous periods of comparable length. This paper presents a statistical summary of the casualties, explores reasons for the losses, and reviews efforts to mitigate the threats.

The Hurricane Forecast Improvement Project

Over the decade prior to 2007, the increasing vulnerability of the United States to damage and economic disruption from tropical storms and hurricanes was dramatically demonstrated by the impacts of a number of land-falling storms. In 2008, the National Oceanic and Atmospheric Administration (NOAA) established the Hurricane Forecast Improvement Project (HFIP) to significantly increase the agencys capability to address this vulnerability and begin to mitigate the impacts. In fiscal year 2009, The White House amended the presidents budget and Congress appropriated funding to achieve a 20% reduction in forecast error (track and intensity) in 5 years with 50% reduction in 10 years. Over the past 3 years, HFIP has built computational infrastructure and implemented a focused set of cross-organizational research and development (R&D) activities to develop, demonstrate, and implement enhanced operational modeling capabilities to improve the numerical forecast guidance made available to the National Hurricane Ce...

Fatalities in the United States from Atlantic Tropical Cyclones: New Data and Interpretation

DOI:10.1175/BAMS-D-12-00074.1 annually, of which one to two made U.S. landfall. R0 found for that period that rain-related incidents were the most common. There were no storm-surge disasters during that period (i.e., storms that took tens to hundreds of lives), as had occurred in previous decades.1 Only six people in total died as a result of storm surge during the 30 years in the R0 study. Any hopes that storm-surge impacts had come under control, however, were soon dashed. A significant uptick in activity began shortly before the end of that period and continues as of this writing. For example, 12 hurricanes, including 7 major hurricanes [those of at least category 3 on the Saffir-Simpson Hurricane Wind Scale (SSHWS)], made landfall on the U.S. Gulf or Atlantic coast in just the two-year period of 2004–05. This paper describes the findings obtained by extending the record to cover a longer period: 50 years, from 1963 to 2012. During that period, about 650–700 Atlantic tropical cyclones occurred, comprising 578 hurricanes and tropical and subtropical storms and around 100 tropical depressions. These additional cases add confidence to findings and conclusions. For context, while operational breakthroughs occur intermittently, several critical components of today’s operational tropical cyclone forecast and warning program started or had their origins in innovations that took place near the beginning of the extended study period, making that period to some degree representative of the current era. For example, satellite images first became available routinely to operational forecasters in 1966. Also, the first operational tropical cyclone forecast models (e.g., NHC67) using predictors

A REANALYSIS OF HURRICANE ANDREW'S INTENSITY

Hurricane Andrew of 1992 caused unprecedented economic devastation along its path through the Bahamas, southeastern Florida, and Louisiana. Damage in the United States was estimated to be

The Life Cycle and Internal Structure of a Mesoscale Convective Complex

26 billion (in 1992 dollars), making Andrew one of the most expensive natural disasters in U.S. history. This hurricane struck southeastern Florida with maximum 1-min surface winds estimated in a 1992 poststorm analysis at 125 kt (64 m s−1). This original assessment was primarily based on an adjustment of aircraft reconnaissance flight-level winds to the surface. Based on recent advancements in the understanding of the eyewall wind structure of major hurricanes, the official intensity of Andrew was adjusted upward for five days during its track across the Atlantic Ocean and Gulf of Mexico by the National Hurricane Center Best Track Change Committee. In particular, Andrew is now assessed by the National Hurricane Center to be a Saffir–Simpson Hurricane Scale category-5 hurricane (the highest intensity category possible) ...

Toward Objective, Standardized Intensity Estimates from Surface Wind Speed Observations

Abstract This paper describes the life cycle and precipitation structure of a Mesoscale Convective Complex (MCC) that passed through the data-collecting network of the Texas portion of the High Plains Cooperative Program (HIPLEX) on 8 June 1980. The MCC was the third in a sequence of five mesoscale convective systems that formed in association with a low-level frontal zone, short-wave perturbations in the 500 mb flow, outflow from previous convection, and upslope forcing. Quantitative radar data, together with surface, upper-air and satellite data, were used to determine the three-dimensional structure of the MCC. Isolated echoes formed over the Davis Mountains of far western Texas and merged as they moved eastward to form a mesoscale convective system with a lifetime of ∼24 h and a low-level precipitation pattern ∼500 km across. The leading edge of the low-level precipitation pattern was a north-south line of intense convective cells possessing the echo structure and low-level kinematic and thermodynamic...

Atlantic Hurricane Season of 1995

Extreme wind climatology and event-specific intensity assessments rely heavily on surface wind field observations. The most widely used platforms sited at airports are the Automated Surface Observing System (ASOS) and its predecessor, the Automated Weather Observing System (AWOS). The terrain immediately surrounding most of these stations may be nominally characterized as aero-dynamically very smooth because of the runways and flat expanses of grass that define most airport layouts. Outside of most airports, a wide spectrum of marine, open, suburban, and heavily built-up terrain conditions are present. The results of this research indicate that the wind speeds recorded by AWOS/ASOS are deeply sensitive to this terrain. Prior research has shown that direct usage of the raw surface data can introduce surface-layer wind speed errors on the order of 30%–40% due to terrain effects. Similar values are observed for gust speeds in this paper, when averaging technique and anemometer response characteristics are co...

Atlantic Hurricane season of 1992

Abstract The 1995 Atlantic hurricane season is described. There were eight tropical storms and 11 hurricanes for a total of 19 named tropical cyclones in the Atlantic basin during 1995. This is the second-largest number of tropical storms and hurricanes in over 100 years of records. Thirteen named tropical cyclones affected land.

Tropical Cyclone Intensity Change before U.S. Gulf Coast Landfall

Abstract The 1992 hurricane season is summarized, including accounts of individual storms. Six tropical storms were tracked, of which four became hurricanes. In addition, one subtropical storm formed during the year. The season will be remembered most, however, for Hurricane Andrew. Although Andrew was the only hurricane to make landfall in the contiguous United States during 1992, it earned the distinction of becoming the most expensive natural disaster in United States history.