Contents Preface xiii Acknowledgements xvii Biographies xviii Chapter 1 Properties of the Atmosphere 1 Key Words 1 Temperature 3 FUN FACT Degree-days A Measure of Energy Consumption 4 Pressure 7 FUN FACT Dangerous Weather Is Always Nearby 8 Moisture 10 Moisture Variables 10 FUN FACT Extreme Indoor Relative Humidity in Winter 13 Phase Changes and Clouds 14 Wind 16 Test Your Understanding 17 Test Your Problem-Solving Skills 18 Chapter 2 Meteorological Measurements 21 Key Words 21 Surface Measurements 23 SCIENCE AND TECHNOLOGY A Historical Perspective on Technology in Meteorology 23 SCIENCE AND TECHNOLOGY The U.S. National Weather Service 24 Rawinsondes 26 ADVANCED TOPIC Hodographs 30 Radar 30 ADVANCED TOPIC The Doppler Shift and Doppler Radars 33 SCIENCE AND TECHNOLOGY Doppler Radar and Tornadoes 34 SCIENCE AND TECHNOLOGY Radar Estimated Precipitation and Flood Forecasting 35 Satellites and Satellite Imagery 36 SCIENCE AND TECHNOLOGY Soundings from GPS and COSMIC Satellites 38 Lightning Detection 41 Test Your Understanding 42 Test Your Problem-Solving Skills 43 Chapter 3 Weather Maps 45 Key Words 45 The Surface Station Model and Surface Weather Maps 46 Pressure as a Vertical Coordinate 48 METEOROLOGY & MAPS Reading Maps 49 Constant Pressure Maps 49 ADVANCED TOPIC 500 mb Maps and Vorticity 53 METEOROLOGY & MAPS Upper Air Maps and the Internet 56 Cross Sections 56 Test Your Understanding 57 Test Your Problem-Solving Skills 58 Chapter 4 Forecasting and Simulating Hazardous Weather 59 Key Words 59 Weather Forecasting Using Computer Models 61 Initializing and Running a Model 62 SCIENCE AND TECHNOLOGY The Origin of Numerical Weather Prediction 67 Output from Models 67 v
vi CONTENTS Limitations of Weather Forecast Models 70 The Mathematical Equations Approximate Some Atmospheric Processes 70 ADVANCED TOPIC Synopsis of Operational NWP Models 71 Errors in the Initial Weather Conditions 72 Inadequate Resolution 72 Research Models 75 FUN FACT A Perspective on Weather Prediction 77 Test Your Understanding 77 Test Your Problem-Solving Skills 78 Chapter 5 Climate and Global Change 81 Key Words 81 Controls of Climate 82 Seasonal Cycle 83 Pressure Patterns 85 Land and Its Effects on Climate 86 Causes of Climate Change 89 ADVANCED TOPIC Determining Past Climates 90 Long Term (Millions of Years) 91 Medium Term (Thousands to Hundreds of Thousands of Years) 91 FUN FACT Ice-Age Weather 93 Short Term (Several Years to Hundreds of Years) 94 EXTREME EVENT The Year without a Summer 96 Recent and Ongoing Climate Change 98 Future Climate Change 100 ADVANCED TOPIC Retreating Sea Ice and Midlatitude Weather 106 Test Your Understanding 107 Test Your Problem-Solving Skills 108 Chapter 6 Atmospheric Stability 111 Key Words 111 The Concept of Stability 112 Lapse Rates 114 Determining Stability 115 Mechanisms That Cause Air to Rise 121 FUN FACT Thunderstorms Over Mountains 123 Stability Indices 124 ADVANCED TOPIC Stability, Capping Inversions and Severe Storms 125 Test Your Understanding 127 Test Your Problem-Solving Skills 128 Chapter7 Forces and Force Balances 131 Key Words 131 Forces That Affect Atmospheric Motion 132 The Pressure Gradient Force 132 FUN FACT Experience the Change of Pressure Across a Hurricane Eyewall 135 The Gravitational Force 135 The Frictional Force 135 The Coriolis Force 136 Newton s Laws of Motion 140 Force Balances 141 Hydrostatic Balance 141 Geostrophic Balance 142 Summary of Forces and Force Balances 144 Geostrophic Balance and the Jet Stream 144 STORMS AND SOCIETY Flying and the Jet Stream 145 Test Your Understanding 147 Test Your Problem-Solving Skills 148 Chapter 8 The Development of High- and Low-Pressure Systems 151 Key Words 151 Force Imbalances 152 Curved Flow 154 Jet Streaks 157 ADVANCED TOPIC Multiple Jet streaks 159 Combined Effect of Curvature and Jet Streaks 160 The Friction Layer 161 Effects of Heating and Cooling 163 Test Your Understanding 167 Test Your Problem-Solving Skills 168
CONTENTS vii Chapter 9 Airmasses and Fronts 171 Key Words 171 Airmasses 172 FUN FACT No Tornadoes from Clashing Airmasses 172 Fronts 174 Cold Fronts 174 Warm Fronts 175 Stationary Fronts 177 Occluded Fronts 177 Dry Lines 178 Upper-Level Fronts 180 Finding Fronts on Weather Maps 182 METEOROLOGY & MAPS The Origins of Fronts on Maps 182 Test Your Understanding 185 Test Your Problem-Solving Skills 185 Chapter 10 Extratropical Cyclones Forming East of the Rocky Mountains 189 Key Words 189 The Environment Prior to the Development of a Cyclone 191 The Initial Development of the Cyclone 192 Initial Movement of the Airmasses 193 Early Weather Along the Fronts 194 East of the Cyclone Center 195 South of the Cyclone Center 195 Upper-Level Front, Dry Line, and Cold Front Present 196 A Pacific Front: The Upper-Level Front and Dry Line Aligned 197 Cold Front Only 198 Northwest of Cyclone Center 198 Summary of Early Weather 198 Storm Intensification 198 ADVANCED TOPIC The Environment on the Great Plains During Cyclone Formation 199 The Mature Cyclone 201 FUN FACT Alberta Clippers 203 The Dissipating Cyclone 204 Continental Cyclones and Global Climate Change 204 Summary 205 Test Your Understanding 206 Test Your Problem-Solving Skills 207 Chapter 11 Extratropical Cyclones Forming along the East and Gulf Coasts 209 Key Words 209 East Coast Cyclones 212 The Environment Before the Development of an East Coast Cyclone 212 The Initial Development of the Cyclone 214 STORMS AND SOCIETY Beach Erosion 215 FUN FACT Bomb Cyclones 216 Fronts, Airflow, and Weather Conditions 216 STORMS AND SOCIETY The Blizzard of 1888 217 Storm Evolution 218 FUN FACT Snowmageddon: Back to Back Nor easters! 218 Gulf Coast Cyclones 220 The East Coast Storm Track 220 The Mississippi Ohio River Valley Storm Track 222 Forecasting and Assessing the Impact of Coastal Cyclones 223 Coastal Cyclones and Global Climate Change 225 Test Your Understanding 226 Test Your Problem-Solving Skills 228 Chapter 12 Freezing Precipitation and Ice Storms 231 Key Words 231 Supercooled Water 232 Vertical Structure of the Atmosphere During Freezing Precipitation 233 Freezing Rain 233 Freezing Drizzle 235
viii CONTENTS STORMS AND SOCIETY The Roselawn, Indiana, ATR72 Aircraft Accident and Freezing Drizzle Aloft 236 Weather Patterns Associated with Freezing Precipitation 236 FUN FACT Wind and Ice Storms 238 FUN FACT Warm Air Aloft! 238 EXTREME EVENT The 1998 Northeast Ice Storm 240 Forecasting Freezing Precipitation 241 Distribution of Freezing Precipitation in North America 241 Freezing Precipitation and Global Climate Change 243 Test Your Understanding 244 Test Your Problem-Solving Skills 245 Chapter 13 Lake-Effect Snowstorms 247 Key Words 247 The Large-scale Weather Pattern for Lake-effect Snowstorms 249 Lake-effect Snowstorm Development 249 Climatology of Lake-effect Snows 251 Organization of Lake-effect Snowfall 255 Wind-parallel Rolls 255 Shore-parallel Bands 255 FUN FACT A Forecaster s Nightmare 257 Vortices 257 EXTREME EVENTS Buffalo Snows of November 2014 258 Lake-enhanced Snowfall 259 Lake-effect Snow and Global Climate Change 260 Test Your Understanding 261 Test Your Problem-Solving Skills 262 Chapter 14 Cold Waves 263 Key Words 263 Formation of Cold Airmasses 265 FUN FACT Extreme Cold in the Arctic 265 Outbreaks of Cold Air into Middle Latitudes of North America 267 EXTREME EVENT Bitter Cold in the Winters of 2014 and 2015 270 ADVANCED TOPIC Snow Cover: Nature s Refrigerator 273 FUN FACT A Generational perspective on Cold Waves 275 Extreme Cold in Europe and Asia 275 Wind Chill 279 EXTREME EVENT The Greatest Arctic Outbreak in the United States: February 1899 281 Cold Waves and Global Climate Change 282 Test Your Understanding 283 Test Your Problem-Solving Skills 283 Chapter 15 Great Plains Blizzards 285 Key Words 285 STORMS AND SOCIETY Hypothermia, frostbite, and blizzards 287 Cold, Wind, and Snow 287 Colorado Cyclones and Blizzards 289 EXTREME EVENT The Winter of Blizzards 291 FUN FACT Snow rollers 292 Alberta Clippers and Blizzards 293 Ground Blizzards 294 Blizzard Safety 294 Forecasting Blizzards 295 EXTREME EVENT The Children s Blizzard of 1888 296 EXTREME EVENT The Great Chicago Blizzard of 2011 296 Blizzards and Global Climate Change 298 Test Your Understanding 298 Test Your Problem-Solving Skills 299 Chapter 16 Mountain Snowstorms 301 Key Words 301 FUN FACT Avalanche! 303 SCIENCE AND TECHNOLOGY Cloud Seeding 304 Source of Mountain Snowstorms 306 Storms Along the Western Slopes of the United States 309 FUN FACT The Chain Law 310
CONTENTS ix Storms on the East Slope of the Rockies 311 Global Climate Change: Mountain Snows and Dwindling Water Supplies 314 Test Your Understanding 316 Test Your Problem-Solving Skills 317 Chapter 17 Mountain Windstorms 319 Key Words 319 The Dynamics of Downslope Windstorms 321 SCIENCE AND TECHNOLOGY T-REX and the Hunt for Rotors 323 Chinook Windstorms of the Rocky Mountains 325 FUN FACT Rapid Temperature Fluctuations 326 Forecasting Chinooks 327 Santa Ana Windstorms of California 329 Katabatic Winds 332 FUN FACT Katabatic Winds in North America 333 Mountain Windstorms and Global Climate Change 333 Test Your Understanding 334 Test Your Problem-Solving Skills 335 Chapter 18 Thunderstorms 337 Key Words 337 Ordinary Thunderstorms 340 FUN FACT How Much Water Is in a Thunderstorm? 342 Mesoscale Convective Systems 343 SCIENCE AND TECHNOLOGY Nocturnal Thunderstorms and Plains Elevated Convection at Night 347 Frontal Squall Lines 350 Supercell Thunderstorms 353 FUN FACT Low Precipitation and High Precipitation Supercells 359 Thunderstorms and Global Climate Change 361 Test Your Understanding 363 Test Your Problem-Solving Skills 364 Chapter 19 Tornadoes 367 Key Words 367 Tornado Formation in Supercells 369 SCIENCE AND TECHNOLOGY VORTEX 372 ADVANCED TOPIC Tornado Winds 378 EXTREME EVENT The Tri-State Tornado of 1925 381 EXTREME EVENT The Tornado Outbreak of 27 April 2011 in the Southeast United States 381 Tornado Formation within Nonsupercell Thunderstorms 382 FUN FACTS Other Tornado-Like Vortices 384 Tornado Statistics 385 Tornado Detection 391 Tornado Forecasting 393 Tornado Safety 394 Test Your Understanding 395 Test Your Problem-Solving Skills 396 Chapter 20 Hailstorms 399 Key Words 398 FUN FACT How Big is a Hailstone? 402 Hail Embryo Formation 404 Hailstone Growth 404 EXTREME EVENT San Antonio s Billion-dollar Hailstorm of April 2016 405 Forecasting and Detection of Hail 408 FUN FACTS Hail and Green Thunderstorms 408 SCIENCE AND TECHNOLOGY Radar Polarization 410 Distribution and Impacts of Hail 411 SCIENCE AND TECHNOLOGY Hail Suppression Can Hail Damage Be Reduced? 415 Test Your Understanding 416 Test Your Problem-Solving Skills 416 Chapter 21 Lightning 419 Key Words 419
x CONTENTS EXTREME EVENT Lightning and Forest Fires 422 The Lightning Stroke 423 Electricity and Charge 423 Charge Distribution and Charging Mechanisms in Thunderstorms 424 Interface charging 424 Induction charging 425 The Lightning Stroke 427 FUN FACT Lightning in Hurricanes 428 Other Phenomena Associated with Electrical Discharges in the Atmosphere 430 FUN FACT Ball Lightning 431 Lightning Safety 434 Test Your Understanding 434 Test Your Problem-Solving Skills 435 Chapter 22 Downbursts 437 Key Words 437 Downburst Formation 438 Environmental Conditions Associated with Microburst Development 440 Downburst Structure 441 Types of Microbursts 444 FUN FACT How Common are Microbursts? 445 FUN FACT Heatbursts: Warm Blasts from Downdrafts 447 The Problem for Aircraft 448 EXTREME EVENT The John F. Kennedy International Airport Crash of Eastern Airlines Flight 66 450 EXTREME EVENT The Andrews Air Force Base Microburst of 1983 451 Modern Technology to Detect Microbursts 452 Prediction of Conditions Favorable for Microbursts 454 Test Your Understanding 455 Test Your Problem-Solving Skills 456 Chapter 23 El Niño, La Niña, and the Southern Oscillation 459 Key Words 459 The Southern Oscillation 461 Evolution of an ENSO Event 463 Consequences of El Niño 464 ADVANCED TOPIC ENSO and Hurricane Activity 466 EXTREME EVENTS El Niño and Snowmageddon in the Winter of 2009 2010 467 The La Niña Phase of the Southern Oscillation 469 Monitoring the Southern Oscillation 470 ADVANCED TOPIC The Strange El Niño of 2015 2016 470 El Niño and Global Warming 471 SCIENCE AND TECHNOLOGY Monitoring the Tropical Pacific Ocean 472 Test Your Understanding 474 Test Your Problem-Solving Skills 475 Chapter 24 Tropical Cyclones 479 Key Words 479 EXTREME EVENTS Hurricanes Katrina (2005) and Sandy (2012) Two Strikes on Our Vulnerable Coastal Cities 484 EXTREME EVENT The Record Setting Hurricane Season of 2005 486 Worldwide Hurricane Occurrences 488 Hurricane Tracks 489 Hurricane Structure 490 Tropical Cyclone Formation and Intensification 496 Trigger Mechanisms for Thunderstorms in the Tropics 496 The Environment Required for Tropical Cyclones to Form from Thunderstorm Clusters 500 How Thunderstorms Organize into a Hurricane 502 Destructive Forces in a Hurricane 508 Storm Surge 508 Other Disastrous Forces in Hurricanes 509 Forecasting Hurricane Tracks and Intensity 511 SCIENCE AND TECHNOLOGY Hurricane Research 511 Global Climate Change: Potential Effects on Hurricanes 514
CONTENTS xi Test Your Understanding 515 Test Your Problem-Solving Skills 516 Chapter 25 Floods 519 Key Words 519 EXTREME EVENTS Worldwide Floods 521 Types of Floods 523 FUN FACT Watersheds, River Stages, and Floodplains 524 North American Flood Weather Patterns 525 Flooding Following Landfall of Tropical Cyclones 525 Flooding from Other Tropical Weather Systems 526 Flooding from Mesoscale Convective Systems 527 EXTREME EVENTS Mississippi River Floods 529 Flooding from Frontal Overrunning 533 Flooding Compounded by Snowmelt 534 Flash Floods of the Desert Southwest 535 Flash Floods Along the East Slope of the Rocky Mountains 536 West Coast floods 540 Flood Forecasting and Safety 542 STORMS AND SOCIETY The Cleanup Who s Responsible? 544 Global Climate Change: Potential Effects on Floods 544 Test Your Understanding 546 Test Your Problem-Solving Skills 547 Chapter 26 Drought 549 Key Words 549 EXTREME EVENTS Drought Disasters Occur Worldwide 550 Indices of Drought 552 Causes of Drought 553 Drought in the Central United States 554 The Drought of the Early 2010s 557 The Drought of 1988 559 FUN FACT Hotter Days and Cooler Nights during a Drought 559 The Drought of the 1930s: The Dust Bowl 561 STORMS AND SOCIETY Drought and Population Migration in the United States 562 Drought in the Eastern United States 563 Drought in the Western United States 565 SCIENCE AND TECHNOLOGY New Methods for Monitoring Drought 570 Historical Perspective on Drought 570 FUN FACT River Flows and Water Rights in the West 571 Global Climate Change: Potential Effects on Drought 572 Test Your Understanding 573 Test Your Problem-Solving Skills 574 Chapter 27 Heat Waves 577 Key Words 577 EXTREME EVENT Recent Heat Waves around the World 578 Measures of Heat Stress 578 EXTREME EVENT How High Can the Heat Index Go? 581 Meteorological Conditions Associated with Heat Waves 582 WEATHER AND SOCIETY Heat Disorders and Safety Tips 583 Urban Heat Island Effect 586 Memorable Heat Waves in the United States 587 Heat Waves of 2012: Record-Setting Spring and Summer Temperatures 587 The July 1995 Heat Wave: Chicago and the Midwest 590 Heat Waves of the 1930s 593 FUN FACT The 1930s and the Advent of Air-Conditioning 595 Global Climate Change: Potential Effects on Heat Waves 595
xii CONTENTS EXTREME EVENT The Russian Heat Wave of 2010 597 Test Your Understanding 598 Test Your Problem-Solving Skills 599 Appendix A Units, Conversions, and Constants 601 Appendix B Blank Maps and Charts 604 Appendix C Geography Overview 608 Appendix D Watches, Warnings, and Advisories for Severe and Hazardous Weather 610 Glossary 613 Index 635