Miles B. Lawrence

ANNUAL SUMMARY: Atlantic Hurricane Season of 2001

Abstract Activity during the 2001 hurricane season was similar to that of the 2000 season. Fifteen tropical storms developed, with nine becoming hurricanes and four major hurricanes. Two tropical depressions failed to become tropical storms. Similarities to the 2000 season include overall activity much above climatological levels and most of the cyclones occurring over the open Atlantic north of 25°N. The overall “lateness” of the season was notable, with 11 named storms, including all the hurricanes, forming after 1 September. There were no hurricane landfalls in the United States for the second year in a row. However, the seasons tropical cyclones were responsible for 93 deaths, including 41 from Tropical Storm Allison in the United States, and 48 from Hurricanes Iris and Michelle in the Caribbean.

Eastern North Pacific Hurricane Season of 2001

Abstract The 2001 eastern North Pacific hurricane season is reviewed. It was a near-average season in terms of the number of systems, with 15 named tropical cyclones of which 8 became hurricanes. One tropical cyclone made landfall in Mexico and two reached category 3 or higher on the Saffir–Simpson hurricane scale. A description of each named cyclone is provided, and track and intensity forecasts for the season are evaluated.

Atlantic Hurricane Season of 2004

Abstract The 2004 Atlantic hurricane season is summarized, and the year’s tropical and subtropical cyclones are described. Fifteen named storms, including six “major” hurricanes, developed in 2004. Overall activity was nearly two and a half times the long-term mean. The season was one of the most devastating on record, resulting in over 3100 deaths basinwide and record property damage in the United States.

Atlantic Hurricane Season of 1999

Abstract The 1999 Atlantic basin hurricane season produced 4 tropical storms and 8 hurricanes for a total of 12 named tropical cyclones. Seven of these affected land. Hurricane Floyd—the deadliest U.S. hurricane since Agnes in 1972—caused a disastrous flood event over the U.S. mid-Atlantic and northeastern coastal states, resulting in 56 U.S. deaths and 1 death in the Bahamas. Heavy rain from a tropical depression contributed to some 400 inland flood deaths in Mexico.

Atlantic Hurricane Season of 1995

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.

Atlantic Hurricane Season of 2002

Abstract The 2002 Atlantic hurricane season is summarized. Although the seasons total of 12 named storms was above normal, many of these were weak and short-lived. Eight of the named cyclones made landfall in the United States, including Lili, the first hurricane to hit the United States in nearly 3 yr.

Trends in track forecasting for tropical cyclones threatening the United States, 1970-2001

Abstract Previous studies have identified statistically significant long-term improvements in forecasts issued by the National Hurricane Center (NHC) for Atlantic basin tropical cyclones. Recently, however, attention has been focused on the forecast accuracy of landfall location and timing, and the long-term improvement trends for this relatively small sample of forecasts were mixed. These results may lead some to conclude that the accuracy of NHC forecasts close to the United States has not improved over time. A statistically robust dataset can be obtained by considering “landfall-threatening” storms, defined as one for which tropical cyclone watches or warnings are in effect for some portion of the continental United States. In this study, long-term trends in accuracy are determined for NHC forecasts issued during these periods of threat and compared to trends for the Atlantic basin overall. A second set of trends are determined for forecasts verifying during the periods of threat. The analysis shows th...

Atlantic Hurricane Season of 1980

Abstract A summary of the 1980 hurricane season is presented. Eleven named tropical cyclones were tracked, of which nine reached hurricane force. Allen, an intense storm, affected a number of Caribbean countries before making landfall on the Texas coast.

Atlantic Hurricane Season of 2000

The 2000 Atlantic hurricane season is summarized and the year’s tropical and subtropical cyclones are described. While overall activity was very high compared to climatology, with 15 cyclones attaining tropical (or subtropical) storm intensity, much of this activity occurred outside of the deep Tropics, over open waters north of 258N. The season’s tropical cyclones were responsible for 54 fatalities, with most of these occurring in Central America in association with Hurricanes Gordon and Keith.

Monte Carlo Significance Testing as Applied to Statistical Tropical Cyclone Prediction Models

Abstract Use of the F test in assessing the statistical significance of a regression equation developed from meteorological data and using the concept of stepwise screening of predictors presents problems in determining degrees of freedom. Some of these problems relate to characteristics of the data. The main problem, however, is the result of making a large number of predictors available to a screening program and retaining only a few. This adds an additional play of chance not ordinarily accounted for in the usual application of the F test. Unless proper compensation is made to degrees of freedom, the variance ratio is overestimated or underestimated, and a prediction equation can be judged significant when it is not, or not significant when it is. The derivation of a test-statistic to avoid this pitfall in the development of statistical models for the prediction of tropical cyclone motion is the subject of the present paper.