September precipitation dominated by Hurricane Ian, while the temperature is like autumn accompanied by the official season change. That set us up for a while leaf color change This year.
Ian Stamp Drought Reappears
A spell of dry weather for most of September abruptly ends with a tropical thunderstorm on the last day of the month. According to the National Center for Environmental Information (NCEI), the statewide average rainfall is 3.84 inches Rated like ours 60th-September driest since 1895. Note that some of Ian’s rain falls after midnight on October 1, so it will count towards the October total.
The heaviest rain at the beginning of the month in the southern mountains on September 4-6. One static front park across the drop area rain more than 6 inches in some areas, with the highest numbers in Transylvania County. A CoCoRaHS observer in the east Brevard record a a total of four days is 10.34 inches above Labor Day weekend.
After that, the middle of the month is especially dry thanks to a high pressure model via the Carolinas. Until September 21, City of Elizabeth receives only 0.17 inches of rain all month, and the northeastern corner of the state is again in Moderate Drought (D1) as rainfall falls short and affects runoff levels and degraded crop conditions. .
Entering the last day of September, parts of the state saw less than an inch of rain for the whole month, including just 0.78 inches in Raleigh after an August is almost equally dry.
But on September 30, Hurricane Ian ashore in South Carolina and brought the month to a wet, windy end across North Carolina. The total number of storms through the morning of October 1 exceeded six inches over parts of the Coastal Plain.
5.92 inches in Hatteras on September 30, more rain than the site had received in the previous ten weeks combined. It was also the wettest day there since May 30, 2016, when Tropical Storm Bonnie just offshore.
Elizabeth also rebounded thanks to Ian and ended the month with 4.49 inches, matching September’s normal 4.52 inches of rainfall.
In some coastal locations, Ian alone was not enough to fully recover from the beginning of the dry month. Wilmington total 5.15 inches compared to the monthly normal of 8.69 inches and Greenville completed 2.75 inches below normal, despite a total of 3.4 inches from Ian on September 30.
However, Ian certainly helped avert an even drier September fate, and it washed away all the drought across eastern North Carolina. After the storm, flow soaring and soil moisture equal or higher than normal except in some parts of the Great Smoky Mountains. Those far west areas receive little rain from Ian and have seen the appearance of Unusually Dry (D0) conditions on the US Drought Watch.
The Heat Is On With Autumn Adjustment
A summer-like start to September has been balanced out by a fall-like final week. For the entire month, the NCEI reports a statewide average temperature of 70.5°For ours The warmest Saturday-September in the past 128 years.
Right from the start, the heat shows no signs of abating, and where is September August left. Charlotte there were eight days in a nine-day period reaching 90°F or higher between August 26 and September 3.
Wilmington there are eight days a whole month with temperatures in the 90s, this has only happened three other times in September in the last 30 years – in 1993, 2010 and 2019.
The temperature peaked in September 22reach 98°F in Raleigh96°F in Charlotte and Lumbertonand 94°F in Wilmingtoneach of which is setting or tied to daily record highs.
That night, our temperature dropped to cold front coincides with the equinox; More on that below. Our first autumn air mass of the year means high temperature mostly in the 70s and dew point in the 30s and 40s in the last week of September.
The end of the month even brings an early winter chill in some areas. Like Canadian high pressure built from the northwest on September 28, some western locations have temperatures at or below freezing.
Interestingly, it wasn’t our mountaintop location that had the coldest temperatures, because the nose of the air is warmer started at about half a mile above sea level that held sites like Bearwallow Mountain and Grandfather Mountain in the mid-30s.
The coolest air poured into the surrounding valleys, and places like Candler reaching 27°F, Celo drops to 29°F, and Waynesville reaches 30°F – the first cold night of the season, almost two weeks before the first fall freeze on average October 10.
It’s also a big difference from where the month begins. After the 4th warmest summer on record based on average lows, Waynesville had an eight-night streak with temperatures in the 60s from September 4-11, much higher than the lows. September’s average is 52.9°F.
That makes the fall arrival even more abrupt — and welcome — statewide.
Autumn sends leaves into action
We often discuss their seasons meteorology definition, grouped by calendar months for the sake of annual consistency and climate similarity. However, we couldn’t help but notice that this year, the first sidereal day of autumn – feceswhen the sun cuts directly across the equator – is a much better fit for our transition to fall-like weather.
On the afternoon of September 22, just before the 9:03 p.m. equinox, temperatures spiked into the 90s, even exceeding our summer normal. After going through that night’s frigid front, the next day’s temperatures were comfortable and reasonable in the 70s.
In RaleighThe 23-degree difference between daily highs of 98°F and 75°F is the largest either side of the equinox since 1995, when the highest reached 87°F on September 22 and just 62 °F the next day.
As the heat fades and still hasn’t returned, our fall-like weather is a sign for the leaves to begin their annual adjustment to reds, oranges and yellows.
Like we did Previously described With the help of Appalachian State biology professor Dr. Howard Neufeld, the green chlorophyll pigments in leaves begin to wear away as days get shorter, temperatures get colder and enzymatic processes slow down.
That allows other colors to form in the spring or – as in red maples – to start forming in the fall to prevent the leaves from absorbing too much solar radiation.
This year, those natural cues have arrived on schedule, and the leaves are responding, too.
“We’ve had nice, cool weather for the past 7 to 10 days [of September]” said Neufeld, who took note of being on time the appearance of peak color in the Boone area – at about 3,000 feet – in mid-October this week.
A wildcard for this year’s weather is wind Ian. Neufeld said the impact was mainly felt at high altitudes, where the leaves were close to peaking when the storm made landfall. That’s because the color change process involves breaking down the cell walls and leaves are eventually cut off from the plant when nutrients and water stop flowing back and forth.
“So if it’s raining and windy near peak color, you can have a lot of leaf drop,” he added.
Elsewhere, Ian was less affected, which further raises hopes for a vibrant show this fall.
“As long as the leaves are green, they’re still firmly attached to the tree, and the wind and rain won’t knock it down too much,” says Neufeld. “Some, but not all.”
For dry and recently drought-hit areas, including parts of the eastern Piedmont and northern Coastal Plains, Neufeld said rain would help prevent premature defoliation from trees like tulip poplars. sensitive to drought conditions.
To stave off a heatwave later this month, Neufeld is projecting the roughly timed arrival of fall colors across the state. He will monitor the conditions throughout the season in Autumn color report and Fall Color Guy Facebook Page.
As the first shades of foliage appear this month, we can think back to a cold September day on the first day of astronomical fall causing shadows to roll and leaves to change.
