This is an ongoing series by the State Climate Office of North Carolina.
North Carolina has a complex climate due to its three distinct regions: the mountains, the piedmont, and the coastal plain. Climate affects many aspects of our daily lives – agriculture, environment, transportation, tourism, and natural disasters to name a few. The State Climate Office of North Carolina was established in 1976, originally at UNC-Chapel Hill, and moved to NC State University in 1980. The mission of the State Climate Office (SCO) is to provide climate related services to the state, local and federal agencies, businesses and the citizens of North Carolina. In 1998, the UNC Board of Governors formally approved it as a Public Service Center.
The State Climate Office is housed in the Research III Building on NC State University’s Centennial Campus, where private industries, government agencies, and University researchers come together and create a unique environment for interaction and advancement.
NC Extremes: Damaging Hurricanes From Slopes to Shores
In September, our NC Extremes post highlighted the strongest hurricanes to affect North Carolina based on the pressure, wind speeds, and storm surge statistics. But when it comes to storm damage, strength isn’t always in the numbers.
All corners of our state have seen destruction and death from tropical systems of varying intensities, whether it was because of flooding, winds, or other hazards. Accounting for all of these impacts, this post looks at some of the most damaging storms to affect various parts of North Carolina since modern record-keeping began in 1851.
It’s worth noting that this is not a comprehensive list of our damaging hurricanes, and it serves to highlight some of the most widespread, costliest, and deadliest storms across the state. As with any weather event, local impacts vary with each storm.
NC Extremes: Our History of Record Heat
Posted on August 20, 2015 by Corey Davis
The heat and humidity of a North Carolina summer can be uncomfortable enough in a typical year. But our state has a history of the heat ramping up, often for days at a time, and pushing our statewide high temperature record — and our discomfort — to even more extreme levels.
Although North Carolina is at a similar latitude to Death Valley, CA, we don’t see the same world record-setting heat as that desert locale. That’s largely because the nearby Gulf of Mexico and Atlantic Ocean, plus our ample surface water and vegetation, help add moisture to the air and moderate our temperatures. This tends to keep our maximum temperatures below 100°F, albeit with often oppressive humidity.
North Carolina’s Dog Days of Summer
Posted on July 23, 2015 by Geneva Gray
It turns out the dog days are more than just a linguistic turn of phrase. They are a distinct time of year ranging from July 3rd to August 11th (40 days) and correspond to when the star Sirius (aka: the Dog Star, part of the Canis Major constellation) rises with the sun. Ancient stargazers noticed that Sirius rises with our sun during the hottest times of year. It was thought that this bright star somehow contributed to the warmth experienced during these hot, summertime days.
Sirius is too far away to contribute to any sensible heat we feel here on Earth, but this does lead a curious climatologist to ask several questions! What are the hottest and most humid 40 days across NC? And do the astrological dog days line up with what we experience in NC?
June Sees Sizzling Heat, Emerging Drought, and Damaging Storms
Posted on July 1, 2015 by Corey Davis
Oh, how quickly things can change! Just last month, we were talking about the return of 90s after a nearly eight month absence. But in June, 90s became the norm and parts of the state hit the 100° mark as the heat peaked mid-month. For many sites, it was the first occurrence of 100° temperatures since July 2012.
A persistent mid-level ridge or high pressure system, denoted by the “H” on the map, set up over the Southeast during mid-June.
The statewide average temperature of 76.54°F made it our 10th-warmest June in the past 121 years. The culprit for our intense heat was a mid-level ridge (see the image on the right) that set up over the Southeast and brought in hot, dry air from the west and southwest.
The hottest temperatures came between the 13th and the 25th. Most of eastern North Carolina hit 100°F on the 16th, then continued on a prolonged period of hot weather. Raleigh hit 95°F on 12 consecutive days — from the 13th through the 24th — breaking the old streak of nine days from July 1977.
Charlotte was also hit hard by the heat. High temperatures hit 100°F at the Charlotte Airport five times. That’s the most ever at this point in the year, exceeding the three days at or above 100°F in the first half of 1952.
Rapid Reaction: The Return of Drought
Posted on June 25, 2015 by Rebecca Cumbie
If you caught the news this morning, you may have heard about the appearance of drought in North Carolina for the first time in over two years! With other notable droughts also in the news — like the one that’s impacting California, Oregon, and Washington — you also might be concerned about whether NC is going to be experiencing horrible impacts any time soon. To shed some light, we’ve written up the answers to a few common questions.
Why are we in a drought?
Precipitation over the western Piedmont has been below normal since, well, last fall. So why hasn’t this part of the state been in a drought before now? Several times during winter and spring, drought seemed on the horizon, but the impact of less precipitation never quite reached the threshold of drought before a storm system would move across the state and allay any concerns about dryness. Recently, however, this has changed.
For the past month, many sites across the state have received an inch or more below what they would normally expect for this same time of year. And in the western Piedmont, several sites are 2 inches or more below their usual for the past month. Combine this with recent heat, and it’s no surprise we’re starting to see impacts. In fact, the two-week period ending June 23 is the warmest on record for many sites across the state, with sites seeing mean temperatures as much as 7 degrees above normal for this period!
A Warm, Dry May Wraps Up a Similar Spring
Posted on June 1, 2015 by Corey Davis
May saw above-normal temperatures continue and a return of dry conditions, especially in western North Carolina. The infographic below includes some statewide headlines from the past month.
Last month’s statewide average temperature of 67.76°F (1.42°F above the long-term average) made it the 29th-warmest May in the past 121 years. Several stations with shorter periods of record had one of their top-ten warmest Mays. That included Raleigh (9th warmest), Asheville (9th warmest), and Hickory (6th warmest).
Although above-normal maximum temperatures helped drive our warm May, we didn’t see a preponderance of 90 degree days. Raleigh, Charlotte, Fayetteville, and Wilmington each had just two days at or above 90°F last month, and Greensboro has yet to hit 90 this year. That makes 263 days and counting since Greensboro’s last 90° occurrence on September 11, 2014, which is the 38th-longest such streak on record. However, it’s far from the record, which came from July 18, 1971, to July 18, 1972 — a full year, or 366 days, between 90° readings in the Gate City…..
NC Extremes: Spring Freezes Prove Costly for Agriculture
Posted on May 1, 2015 by Corey Davis
May is generally associated with warming temperatures, springtime thunderstorms, and rain showers to feed emerging plants. But several times in recent history, including a record-setting event in early May of 1963, the onset of spring has been interrupted by a wintertime relic when a costly freeze occurred across the state.
Winter Recap 2014-15: A Warm Start with a Frigid, Frozen Finish
Posted on March 24, 2015 by Corey Davis
The meteorological winter — December through February — finished as the 40th-coolest and 33rd-driest winter statewide out of 120 years of record. But the whole winter wasn’t as cool as that figure suggests. We had above-normal temperatures for much of December and near-normal temperatures in January, with little to no measurable snowfall outside of the high elevations in the mountains.
NC Extremes: Storm of the Century Smashed Snowfall Records
Posted on March 12, 2015 by Corey Davis
An old adage says that March comes in like a lion and goes out like a lamb. But what about the middle of the month? It’s often in between our big winter weather events and our springtime severe weather events. However, in mid-March of 1993, both seasons converged along the U.S. east coast in a storm so colossal and impactful that it’s now called the “Storm of the Century”.
The storm began like many that affect North Carolina: as a weak low pressure system in the Gulf of Mexico on Friday morning, March 12th. The waters of the Gulf were particularly warm for that time of year, which allowed the storm to begin strengthening and organizing, and a southerly flow provided a continuous feed of moisture as the low moved east….
Fe-BRRRR-uary Was Cold and Wintry in NC
Posted on March 2, 2015 by Corey Davis
If you were born in the 80s or later or have moved to North Carolina since then, this was probably the coldest February you’ve ever felt in this state. The preliminary rankings show it was the 10th-coolest February since 1895 and the coldest since 1978. And many weather stations ranked even higher than that.
NC Extremes: Arctic Air Masses Pack a High-Pressure Punch
Posted on February 25, 2015 by Corey Davis
When it comes to moving the mercury in barometers up to record-setting levels, nothing does the trick quite like a wintertime Arctic high pressure system. But before we get to North Carolina’s high pressure records, let’s briefly review air pressure, including how we measure it and how wintertime Arctic highs get so strong.
Simply defined, air pressure is the weight of the air above you. As you rise in elevation, there is less air above you and the pressure is lower. This creates some challenges when comparing air pressure measurements at different locations. For example, in Boone — at 3,000 feet above sea level — the typical local barometric pressure, or station pressure, is about 900 millibars. However, you wouldn’t expect to see pressures this low at a low-elevation site like Wilmington unless something like a strong hurricane was moving through.
To account for these elevation-induced differences and make site-to-site comparisons easier, weather stations often report the sea level pressure. This is essentially the pressure a site would experience if it were at sea level, or zero feet in elevation. Under standard atmospheric conditions at sea level, typical pressures are about 14.7 pounds per square inch, or, equivalently, 29.92 inches of mercury or 1013.25 millibars.
NC Extremes: The Coldest Day Redefined Records
Posted on January 21, 2015 by Corey Davis
Today’s post looks at the event that brought the coldest air on record to most of the state.
They say that records are made to be broken. But on January 21, 1985, the temperatures were so frigid that this event is now known by the superlative, “the Coldest Day”. On that morning, North Carolina temporarily became an ice box, rewriting our low temperature records in the process.
***All Images on this page courtesy State Climate Office of NC***