December temperature marked by a massive cooldown just in time for Christmas. Rain all month lift the mountains out of drought. And a New tool features help us look back on the past month.
Temperature drops for the holidays
After a warm start to December, our temperatures dropped during the Christmas cold air outbreak, leaving average monthly temperatures slightly below normal. The National Center for Environmental Information (NCEI) records a preliminary statewide mean temperature of 41.6°For ours 61-cool December over the past 128 years.
The first week of the month saw our highs rise nearly 10 degrees above normal, with mid-60s temperatures east of Piedmont and a cool 80-degree day in Wilmington above December 7 under the influence of offshore high pressure.
A series of the way forward mid-month helped cool our temperatures down to near-normal levels and brought clouds and rain over the western 2/3 of the state.
But the most drastic temperature change occurred on December 23 when cold air combined with Arctic High Pressure System spread southward and infiltrated most of the continental United States.
By the next morning, clear skies, calm winds and a cold front had brought temperatures down to levels not seen in several years. Mount Mitchell recorded a low that morning of -21°F, which ranks as the 7th coldest in the state’s 90-year history of highest peak weather observations.
Elsewhere on the Mountain, our ECONet station on Mountain Spring Wine in Macon County bottomed at -15°F, which was the coldest day there since observations began in 2002. Locations include Asheville (0°F), boone (-8°F) and flat springs (-11°F), it was the coldest morning since an arctic air mass arrived early January 2014.
Most locations in Piedmont dropped to single digits on the morning of December 24, which is a rare event especially given the absence of snow on the ground. Greensboro recorded a low temperature of 5°F, Charlotte reached 9°F, and Raleigh the temperature hit 10°F and it was the coldest morning since the next 10°C reading blizzard January 2018.
Across the Coastal Plains, temperatures are often in the teen years, including 13°F in Rock mountain15°F in Greenvilleand 19°F at Mantis. In those areas, it’s a chill reminiscent of December 1989, though without snow storm comes with that year’s Christmas cooldown.
Temperatures rise only slightly on Christmas Day, with high temperature in the 10s and 20s in the Mountains, in the 30s all over Piedmont and barely reached the low 40s in the east.
For places like Brevard (high temperature on December 25 was 22°F), airy mountain (28°F) and Morganton (30°F), it was the coldest Christmas afternoon since 1983. It was also a big difference from last year’s t-shirt weather, when highs reached in the 70s statewide.
However, that warmth reappeared before the end of 2022. The return of high pressure ushered in above-normal temperatures less than a week after the deep freeze. Parts of eastern North Carolina hit 70s lows in December 30 and 31 to end the year on a high – or at least high heat.
The mountain range ended drought, then it snowed
December continues the fall wet weather pattern in the west while eastern North Carolina remains dry. The NCEI reports a statewide preliminary average rainfall of 3.10 inches and ours The 51st dry month of December dating from 1895.
In the mountains, where moderate (D1) and severe (D2) droughts occurred at the beginning of the month, the first few weeks of December saw many heavy rains that wiped out any drought or drought. in that area of the state. .
Murphy increased by 2.24 inches on December 6 alone and ended the month with 6.23 inches, which is the 14th wettest December since 1967. That rain helped fuel the flow levelfell for most of September and October but recovered starting from Hurricane Nicole mid-November.
Another downpour on December 14-15 brought a wide inch or more through the Mountains and Piedmont, including 2.20 inches at our ECONet station in Oxford. That site had 4.52 inches for the whole month, which was the 7th wettest December in the past 23 years.
For eastern North Carolina, the wettest and most impactful rain event comes on December 22 as a low pressure system developed offshore.
That rain came as a welcome relief for coastal areas that started the month with a string of dry days. From December 1 to 14, Wilmington received only 0.08 inches of rain. They picked up 1.45 inches on December 22, though it still ended with the 37th December drought recorded there, and a Moderate Drought persisted over most of the Coastal Plain.
When the Arctic front passed the next day, it created strong winds across the state. Our Mount Mitchell The ECONet station measured wind gusts of 76.5 mph at 11:32 a.m. and ten consecutive hours of wind chills below -50°F, including a minimum of -58.8°F shortly after midnight. The night of December 24. That was the coldest wind chill on record for our Mount Mitchell station dating back to 2008.
grandfather mountain cold wind peaks of -55.6°F and Mount Jefferson there was a wind chill of -45.6°F after the wind had passed. Our coastal locations in clinton, Goldsboro, Kinstonand Plymouth All recorded gusts exceed 50 mph.
Those strong westerly winds also create a wash sound along the Outer Banks closed part of Highway 12. And as the cold air swept behind, the standing water on the road froze into ice. black ice and other slippery spots overnight.
It wasn’t the only area where something froze on the ground during the holidays. Temperatures are cold enough for precipitation to fall in the form of snow at some alpine locations, providing a White Christmas for a lucky few.
Mount Mitchell 4 inches of snow accumulated on December 23, while oak mountain 3 inches and measured by CoCoRaHS observers near Boone up to an inch above the ground.
As for the rest of us, we’ll have to see if January – the most snowy month in terms of our climate and when almost all of our snow falls last year – brings the same winter scenes as we start 2023.
December, as told by Threshold
We recently implemented a new feature in Station Scout, our tool for viewing statewide weather stations. On the Threshold panel, you can view the history of occurrence of specific weather conditions, such as temperatures above or below a specific threshold value, and summary statistics including the first and last days of the average. average per year meets that threshold.
This panel replaces ours Climate threshold tool while maintaining its image and functionality, and expanding them to cover more station networks.
Using the Threshold table, we can put some December weather information into climate context. For example, let’s first consider the occurrence of daily minimum temperatures below 10°F at Charlotte:
As the yearly chart shows, single-digit lows were once a fairly common event, occurring up to four times per year in the 1960s. However, those chilly mornings have recently become a turning point. should be much rarer, with only 8 occurrences totaling over the past two decades, including December 24, 2022.
On the other end of the temperature spectrum, we can see how common it is for maximum temperatures to reach at least 70°F in Wilmington at this time of year:
Port City has historically averaged 6 warm December days, but each of the past four years has exceeded that average, as seen on both the Annual Chart and Annual Table Visualization ( shown above). WIlmington has 7 December days in the 70s or warmer in 2022, 18 such days in 2021 and a record 21 warm days in December 2015.
Finally, for high-altitude areas that got snow last month, we can see how this season’s first snowfall compares to historical averages.
Above Mount Mitchell, on average the first day of measurable snow since 1980 is November 11. That makes the first snowfall of this year on December 23 more than a month later than usual. The highest point in our state can also snow in late April, with the average last snow day being April 17.
To see similar stats for weather stations near you, visit our website Station Scout Toolselect a station using the map and search options, then click the Threshold tab to start exploring.
And for more perspective on the past year, join us virtual to know Summary of weather in 2022 webinar on Tuesday, January 17 at 11 a.m. Registration is required using this sampleand you’ll get a prompt and a link to join the webinar via Zoom.
