38Types of Precipitation Orographic PrecipitationConvectional PrecipitationCyclonic Precipitation
39Orographic Precipitation Occurs in the mountains and western piedmontTropical air mass reaches the mountains and cools adiabatically as it rises along the mountains.When it reaches the dew point (100% humidity), it results in rain or snow.
40AdiabaticAdiabatic: describing a process in which there is no transfer of heat into or out of the system in question.Saturation-adiabatic process: an adiabatic process in which the air is maintained at saturation by the evaporation or condensation of water substance, the latent heat being supplied by or to the air respectively; the ascent of cloudy air, for example, is often assumed to be such a process.
41Convectional Precipitation Primarily a warm weather phenomena—isolated summer thunderstorms.Most summer rain comes from convectional precipitation.The heat of day on the air and land heats an already warm maritime tropical air mass.As the heated and moist air rises, it cools and its water vapor turns into rain.
42Cyclonic Precipitation Conventional low pressure storms.Generally move west to east across the United States.Generally fall, winter and spring in North Carolina.Warm fronts tend to provide light, prolonged precipitation.Cold fronts tend to provide brief, heavy showers.
45Climatic Measures Average Temperatures Frost-Free Seasons Average Annual RainfallWhile North Carolina is located in a warm temperate zone, its diverse regions can experience a great variety of weather conditions. While locations in the mountains may see average temperatures of 30 degrees Fahrenheit in January and 65 degrees Fahrenheit in August, locations in the coastal plains can often experience January averages in the mid 40's and August averages in the 90's. The state averages 44 inches of rainfall each year, and 5 inches of snow.
46Hickory Climate Summary NC Climate SummaryJanFebMarAprMayJunJulAugSepOctNovDecYearAverage Max. Temperature (F)50.853.160.570.578.485.087.186.081.372.461.051.669.8Average Min. Temperature (F)29.730.536.745.554.562.565.965.059.147.536.930.147.0Average Total Precipitation (in.)3.974.144.703.773.914.414.765.353.753.613.004.1849.54Average Total SnowFall (in.)3.01.91.70.00.18.5Average Snow Depth (in.)Hickory Climate SummaryJanFebMarAprMayJunJulAugSepOctNovDecYearAverage Max. Temperature (F)51.155.561.970.076.181.584.684.579.872.760.452.969.4Average Min. Temperature (F)29.430.236.543.152.861.165.365.559.248.436.131.646.7Average Total Precipitation (in.)4.604.215.693.606.465.533.883.734.143.463.764.7853.84
52Average Seasonal Hours of Sunlight in NC The number of hours during which the sun is visible (black line), with various degrees of daylight, twilight, and night, indicated by the color bands. From bottom (most yellow) to top (most gray): full daylight, solar twilight (sun is visible but less than 6° from the horizon), civil twilight (sun is not visible but is less than 6° below the horizon), nautical twilight (sun is between 6° and 12° below the horizon), astronomical twilight (sun is between 12° and 18° below the horizon), and full night.
53Daily Sunrise & Sunset with Twilight and Daylight Savings Time The sunrise and sunset times over the course of the year 2012 (black lines), with twilights (solar, civil, nautical, and astronomical) indicated by the color bands from yellow to gray. The transitions to and from daylight savings time are indicated by the "DST" labels.
54Median Cloud Cover in NC The median daily cloud cover (black line) with percentile bands (inner band from 40th to 60th percentile, outer band from 25th to 75th percentile).
55Average Relative Humidity in NC The average daily high (blue) and low (brown) relative humidity with percentile bands (inner bands from 25th to 75th percentile, outer bands from 10th to 90th percentile).
56Average Dew Point in NCThe daily average low (blue) and high (red) dew point with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).
57Average Wind Speed in NC The average daily minimum (red), maximum (green), and average (black) wind speed with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).
58Human Effects on Geography In the 1800s (and earlier) eastern North Carolina's economy affected the landscape:Naval Stores—use of region’s longleaf pine for timber and tar:Some barrier island forests harvested to the point of deforestation.Parts of the coastal plains destroyed by insect infestations, burnings, windstorms, etc., once trees were cut with V’s to drain sap for tar.Draining of swamps:Drained for farming and rice growing.Draining lowered water levels in rivers and allowed for major forest fires.
59Affects of Climate on History In 1998, scientists discovered by measuring tree rings in bald cypresses that in the late 16th and early 17th centuries, two major droughts occurred:—the worst drought in the last 800 years.—the driest seven-year period in the last 800 years.