"The water keeps a damper on 

 things," she says. 



Typical day, afternoon: The con- 

 vection of warm, moist air is piling up 

 mounds of cumulus clouds along a 

 scrimmage line somewhere inland, 

 where the prevailing wind and sea 

 breeze are butting heads. The plot 

 thickens. Thunder becomes a 

 background theme in the music of the 

 beach. 



Thunderstorms 



If you're still tuned in, the next 

 character you're likely to expect on the 

 scene is a thunderstorm. 



Thunderstorms erupt in the coastal 

 areas of North Carolina 40 to 50 times 

 a year. Wilmington averages seven 

 days of thunderstorms in June, eleven 

 in July and nine in August. 



"A fair statement about the North 

 Carolina coast," Hinn says, "is that 

 there's usually a chance of afternoon 

 showers and thunderstorms." 



Thunderstorms brew in two ways. 

 The first and most common type 

 begins as a concoction of moist air, 

 heated by the land, that rises into the 

 lower levels of the atmosphere, where it 

 condenses and forms clouds. If there 

 are winds aloft, say at 35,000 to 50,000 

 feet, they vent the system, as a breeze 

 does a chimney, and allow the clouds to 

 pile up, sometimes as high as ten miles. 



The second general type of thun- 

 derstorm forms when an invasion of 

 cool, heavy air pushes under warm, 

 moist air. The warmer air, being 

 lighter, can rise and ride the cool air 

 piggyback. Result: condensation and 

 clouds. This interaction can bring a 

 line of thunderstorms across the 

 beaches at any time of day. 



In either case, the churn of wind, 

 warmth and moisture is likely to spew 

 rain and crackle with lightning. 



"Winds and seas also come up with 

 the thunderstorms," Hinn points out, 

 "because you're getting the updraft, 

 which is causing those clouds to build 

 to such tremendous heights, but you're 

 also getting the downdraft, which most 

 people have experienced as that first 

 gust before the storm." 



As the sea breeze runs out of gas late 

 in the day, these thunderstorms or 

 showers can move off and miss the 

 beaches altogether, or they can march 

 toward the sea on the prevailing winds. 



If the showers do come, how long 

 will they last? Hinn says that because 

 the average summer storm has a 



diameter of about ten miles and travels 

 about 20 mph, it usually causes about 

 one-half hour of disruption. 



Once past the beach and over cooler 

 water, the storms usually mellow until 

 they reach the warm Gulf Stream, 

 20 to 60 miles off shore. "It's like tak- 

 ing a pot of hot water, and it's bubbl- 

 ing over the land, until it gets out over 

 the water and calms down some. Then 

 it gets out over the Gulf Stream and 

 starts bubbling again." Hinn calls 

 these off-shore thunderstorms "our 

 own coastal fireworks display." 



But a few times each year, things fly 

 off the handle. If a high-powered 

 weather system moving east across the 

 state lands in the lap of a local storm, 

 the result is often a super-charged 

 thunderstorm with high winds, driving 

 rain and, occassionally, tornadoes. 



The great acceleration of wind in 

 these super-storms can uproot tents 

 and raise waves stout enough to swamp 

 boats and flood low-lying acreage. 



By the time things get that out of 

 hand, the amateur meteorologist 

 should be exactly where the pros are — 

 under shelter. 



Fall and winter 



A gradual shift in the flow of air 

 brings winds out of the north in late fall 

 and winter, and signals cold weather. 

 The ocean surrenders its heat slowly, 

 so the waters along the coast stay 

 warm, often in the 70s and low 80s, un- 

 til October or November. The temper- 

 ing effect of the water postpones very 

 wintry weather until the months from 

 December through February, when 

 winds are often rough and waves com- 

 monly reach ten feet. Rain and fog are 

 also more likely than in summer. 



Interrupting this pattern of north 

 winds, rain and fog is an occasional 

 "northeaster," the infamous storm 

 system most common in the winter 

 months. 



Northeasters are low pressure 

 systems migrating east, or north along 

 the coast. Since these low-pressure 

 systems are counterclockwise motions, 

 the force of their winds often slams into 

 the coast with a hooking motion from 

 the northeast. Sometimes these winds 

 reach hurricane force and the waves 

 they generate can maul real estate and 

 rearrange the landscape. Powerful 

 northeasters are often more destructive 

 than tropical storms, since the 

 northeasters are very large and can 

 blow relentlessly for days. 



The "typical" summer morning: 

 sunny-side up at sunrise 



