North Carolina Climate NOAA/National Weather Service Raleigh, NC North Carolina Climate Phillip Badgett – NWS Raleigh, NC phillip.badgett@noaa.gov National Weather Service

North Carolina Topographic Map National Weather Service

North Carolina’s Unique Topography and Geography The Appalachian Mountains… the proximity to the Gulf Coast and the Atlantic Ocean… and Gulf Stream… all have a profound affect on North Carolina’s Climate. Elevations range from sea level to 6684 feet at Mt. Mitchell. Geographic regions include the Mountains… Foothills… Piedmont… Sandhills… Coastal Plain… Coastal Area… and Outer Banks. National Weather Service

Factors that Influence North Carolina’s Climate Mountains and moisture sources (Gulf and Atlantic) play major roles in Cold Air Damming (CAD) and Thermal Moisture Boundary (TMB) formation… and resultant severe weather and winter weather climatology. Tornado outbreaks are often tied to location of TMB. (March 1984, November 1988, November 2008 just a few examples). Mountains can disrupt or weaken tornado outbreaks in Tennessee Valley from affecting our Piedmont (April 3-4, 1974 event). Mesoscale Convective System (MCS) crossing mountains (often break up crossing the mountains… but can re-intensify east of mountains. (RNK study). CAD results when cold stable air arriving from the northeast is dammed up along the mountains. National Weather Service

Factors that Influence North Carolina’s Climate CAD (profound affect on North Carolina’s Climate often enhancing winter storms… severe weather near TMB along CAD periphery to the east and south… and enhancing or reducing QPF. National Weather Service

TMB Severe Weather 3/28/1984

March 1984 Tornadoes

Cold Air Damming National Weather Service

CAD with Ice Storm Dec. 2002

Ice Accrual December 2002

North Carolina’s Annual Precipitation National Weather Service

North Carolina’s Annual Precipitation Wettest weather station in North Carolina… 91.72 Inches (Annual Average)… Lake Toxaway, Transylvania County Driest weather station in North Carolina… 37.32 Inches… Asheville (downtown), Buncombe County National Weather Service

North Carolina’s Annual Precipitation Wettest calendar year for any station… 129.60 Inches (1924), Rosman, Transylvania County Driest calendar year for any station… 22.69 Inches (1930), Mount Airy, Surry County National Weather Service

North Carolina’s Precipitation Influences Primary storm tracks, CAD, and TMB/Coastal Fronts (cool season). Tropical cyclone tracks and low level boundaries (warm season). Piedmont trough position (enhances summer pulse storms and resultant QPF and pulse severe). (Reference Tony Ray study). Sandhills enhanced summer rainfall due to differential heating of sandy soil versus other soil types surrounding the region. (SCO study). National Weather Service

North Carolina’s Annual Temperature National Weather Service

North Carolina’s Annual Temperature Warmest weather station in North Carolina… 63.8 degrees… Wilmington, New Hanover County Coldest weather station in North Carolina (where people actually live)… 48.8 degrees… Banner Elk, Avery County. 43.8 degrees… Mount Mitchell, Yancey County National Weather Service

North Carolina’s Annual Temperature Lowest temperature on record was 34 below at Mount Mitchell (January 21, 1985). Raleigh was 9 degrees below zero on that same date for lowest all time in the Raleigh area. Highest temperature on record was 110 degrees at Fayetteville (August 21, 1983) Raleigh was 101 degrees that same day. National Weather Service

Winter Weather Climatology Winter weather season typically runs between December and March. Predominate snow events are most common over the northwest… with least occurrences along the coast. Freezing rain is most often predominate over the Northern Piedmont Damming Region (due to CAD). Sleet is rarely the predominate winter storm precipitation type (it is typically found with transition zones of precipitation). National Weather Service

North Carolina’s Annual Average Snowfall National Weather Service

North Carolina’s Number of Days with Snow and Sleet Accumulation National Weather Service

North Carolina’s Number of Events per Year with Sleet and Freezing Rain National Weather Service

A Typical Strong Winter Storm with Cold Air Damming National Weather Service

Severe Weather Climatology Three Distinctive Severe Weather Seasons Primary (late February through May) Pulse Severe (June through August) Secondary (October and November) National Weather Service

Tornado Track (EF3 and Greater Since 1950) National Weather Service

Monthly Distribution of Tornadoes for the Raleigh CWA National Weather Service

Monthly Distribution of Severe Thunderstorm Wind Events for the Raleigh CWA National Weather Service

Hourly Frequency of Severe Thunderstorm Wind Events for the Raleigh CWA National Weather Service

Monthly Distribution of Severe Thunderstorm Hail Events for the Raleigh CWA National Weather Service

Hourly Frequency of Severe Thunderstorm Hail Events for the Raleigh CWA National Weather Service

Flash Flood Climatology National Weather Service

River Flood Climatology National Weather Service

All Hurricanes Affecting North Carolina 1851-2008 National Weather Service

June Hurricanes Affecting North Carolina 1851-2008 National Weather Service

July Hurricanes Affecting North Carolina 1851-2008 National Weather Service

August Hurricanes Affecting North Carolina 1851-2008 National Weather Service

September Hurricanes Affecting North Carolina 1851-2008 National Weather Service

October Hurricanes Affecting North Carolina 1851-2008 National Weather Service

November Hurricanes Affecting North Carolina 1851-2008 National Weather Service

Record Tropical Season 2004

Tropical Cyclone Tracks that Produced Tornadoes over RAH CWA (1950 through 2008)

Credits North Carolina State Climate Office Southeastern River Forecast Center National Climatic Data Center Brandon Dunstan Jonathan Blaes, Darin Figurskey, Ryan Ellis, Brandon Locklear, Mike Moneypenny, Barrett Smith - (NWS RAH). National Weather Service