A review from The Bulletin of
the AMS, November 2004
The Philadelphia Area Weather Book:
Including Delaware, the Poconos, and the New Jersey Shore
Reviewed by Al Cope
As one who shares responsibility for issuing all kinds of weather forecasts and warnings for the region around Philadelphia, I can appreciate the scope of the task confronting the authors of The Philadelphia Area Weather Book. Yet I believe Jon Nese and Glenn Schwartz have done an outstanding job describing and explaining, in layman's terms, the wide variety of weather phenomena that affect the city of Philadelphia and its environs. Their book would be of interest especially to professionals and amateur weather enthusiasts who live in the Philadelphia region, or who grew up there or otherwise have spent any significant amount of time in the area. As described in the subtitle, the "Philadelphia Area" also includes Delaware, the Poconos, and the New Jersey shore.
Concerning the authors, Jon Nese is a graduate of the Pennsylvania State University (PSU), the former chief meteorologist at the Franklin Institute, and now appears regularly as a storm analyst on The Weather Channel. Philadelphia native Glenn Schwartz is also a PSU graduate, has a wide variety of experience in weather broadcasting, and is currently chief meteorologist for NBC-10 TV in Philadelphia.
The book begins with a foreword by Pennsylvania governor Ed Rendell (former mayor of Philadelphia), who draws some interesting connections between weather and city politics. The main body of the book is divided into seven chapters: one for each season, plus chapters on local weather history, possible future climate, and the basics of weather forecasting. Following chapter 7 are two appendices listing daily and monthly climate records for Philadelphia, Wilmington, Delaware, Allentown, Pennsylvania, and Atlantic City, New Jersey.
The first chapter, entitled "History of Weather Science and Observing in the Philadelphia Area," starts with the earliest colonial weather records from the seventeenth century. It goes on to describe the pioneering meteorological work of Philadelphians Benjamin Franklin and the lesser-known James Pollard Espy, who championed the cause of meteorology in the early life of both the Franklin Institute and the Smithsonian Institution. A brief history of the NWS (which grew from the efforts of Espy and others) concludes with a description of the modern NWS, with an emphasis on modern observing systems such as weather radar and satellites.
Chapter 2, "Basics of Weather and Weather Forecasting," does a good job of describing in layman's terms the basics of the science of meteorology, including seasonal variations, pressure and wind, fronts and jet streams, etc. It goes on to describe the climate of the Philadelphia region, and explains the influence of mountains to the west, the Atlantic Ocean to the east, and the urban heat islands in between. The chapter concludes with a section on modern weather forecasting, including the first numerical weather prediction on the ENIAC computer, created at the University of Pennsylvania in Philadelphia. The authors even venture into the relatively new topic of ensemble forecasting with computer models as part of their discussion about forecast uncertainty.
The first of the seasonal chapters is chapter 3, "Winter." Here the authors discuss various factors that make winter forecasting difficult in the Philadelphia region. Many places could probably claim to have the country's most changeable weather, but the authors make a good case for Philadelphia, with its rapid changes in precipitation type and large local variability in snowfall amounts. The section on "Winter Cold" includes a discussion on the new windchill index, while "Winter Snow" describes the basic setup for nor'easters and reviews some of the biggest mid-Atlantic snowstorms of recent winters. The chapter concludes with a historical review of extreme winters, going back to the 1600s. The authors suggest that some of these early winters may have been worse than any in modern times.
Next comes chapter 4, "Spring." Here the emphasis is on storms, both nor'easters and thunderstorms. Even though nor'easters are usually associated with winter, they have a section in this chapter, partly because one of the most famous and powerful nor'easters occurred in March 1962. This and several other nor'easters are documented, including the "Perfect Storm" of 1991. Attention then shifts to thunderstorms and severe weather, including sections on lightning, winds, hail, river flooding, and tornadoes. The latter section includes documentation of some historical Philadelphia tornadoes going back as far as the 1700s.
Chapter 5, "Summer," begins with a discussion of heat and humidity, which combine to form one of the more dangerousbut often underappreciatedweather hazards. Among other things, the authors describe how Philadelphia experienced a deadly heat wave in July 1993, which led to a pioneering new heat watch/warning/advisory system for the city. At the other extreme, accounts from a nearby New Jersey resident from the year 1815 show how that was the "Year Without a Summer." The Chapter continues with a discussion of flash flooding, followed by a section on drought, which can occur any time of year, but whose effects are most acute in summer. Several pages are devoted to air pollution issues, with emphasis on ozone as a harmful pollutant near the ground, but an essential shield against ultraviolet radiation in the stratosphere. The chapter ends with a section entitled "The Shore," including the somewhat controversial topic of beach replenishment. The authors give a reasonably balanced discussion, with equal time for opposing expert opinions.
The final seasonal chapter is "Autumn." This chapter is dominated by the main weather threat in an otherwise relatively tranquil time of year, namely hurricanes. Different sections cover the basics of how hurricanes form, how they are forecast, and their main threats: wind, storm surge, and inland flooding. Of special interest to Philadelphia-area residents is the section on the hurricane vulnerability of the New Jersey and Delaware coasts, and the following section on noteworthy hurricanes that affected the Delaware Valley region, going back to the 1700s. There is also a brief fictional but intriguing "hurricane nightmare" scenario describing what might have happened in 1996 if Hurricane Edouard had not recurved, but instead continued moving northwest from the Atlantic into Delaware Bay.
The final chapter is entitled "Philadelphia's Future Climate." This chapter covers seasonal forecasting, with emphasis on the effects in the Philadelphia area of El Niņo and La Niņa, plus the North Atlantic oscillation and other teleconnections. The authors then tackle the subject of global warming. Their discussion seems balanced and scientifically based, distinguishing between what is known and what is uncertain. The conclusions are supported by the views of several climate experts and expert panels.
One other unique feature of this book is a collection of "Stories from the Trenches" scattered throughout the chapters. These stories give the reader some feeling for what it's like to be a broadcast meteorologist in a tough forecast situation. The descriptions cover such events as Hurricane Agnes; the May 1998 Lyons, Pennsylvania, tornado; and several notable winter storm forecasts, both hits and misses.
In summary, I can definitely recommend this book to anyone interested in weather, especially in the Delaware Valley region. It is amply illustrated, with at least one picture or diagram on almost every page. (Unfortunately, color illustrations are limited to a few plates.) While not technical in nature, the explanations in the book are scientifically sound and could serve as a general introduction to a variety of weather-related topics. As noted above, the authors take a balanced and science-based approach to controversial topics such as global warming. I will conclude by noting that I recently recommended this book to one of the new forecasters at our NWS office, not as a technical forecasting reference, but as a way to become familiar with the variety of local forecast problems we encounter, and with some of the benchmark historical weather events against which future storms are measured.
Al Cope is the science and operations officer at the National Weather Service Forecast Office in Mount Holly, New Jersey, located just outside of Philadelphia.