With the year 2017 coming to an end tonight the Foothills Weather Network and its team of Meteorologists would like to take a moment and look back at three of the big weather stories for the year. Needless to say our part of the world experienced a lot of different weather phenomena from winter weather to severe weather and tornadoes to tropical weather. This has been a very active past 12 months and signs indicate that we could see more active weather in 2018.
After some debate along our forecasters and contributors within the company we came up with three main themes…
#3. The return of La Nina:
After dealing with either a neutral or El Nino the ENSO returned to a weak La Nina phase during 2017. For those who are not familiar with La Nina, that is when a cooling of waters occur in the Equatorial Pacific Ocean. As you can see in the image below, a La Nina is based east of the International Date Line and has locked in here at the end of the year.
The changes associated with La Nina began in the spring time. After dealing with a relatively dry January and February, things began to change as March arrived. One of the key ingredients in a La Nina during the warmer months is general weakness or trough across the Southern tier of the country, something that actually was a significant difference from priors years. It allowed our part of the country to get in on solid rainfall chances once the seasons changed. It helped keep our region from getting locked into a drought conditions…another change from springs prior.
Once we got into the summer the developing Nina began to spread its influence more into the tropical regions. Winds this summer were less hostile than we had seen in the Atlantic basin in several of the hurricane season’s prior. The combination of less shear and continued warm sea surface temperatures made tropical cyclogenesis a lot more threatening as we saw with the very active hurricane season. Rapid intensification of storms occurred frequently. Our coverage area began to see at least indirectly those consequences as late summer and early fall arrived.
Now that we are into winter, La Nina conditions usually yield dry and milder weather. Of course, that said we have already experienced one winter storm and are in the midst of an arctic outbreak…so in a lot of ways the winter here early on hasn’t acted like that of a typical La Nina.
#2 December 8-9th Winter Storm:
It’s not totally unheard of to have a winter storm impact the Western Carolinas in early December but still it is very noteworthy when it happens. The winter storm of Friday December 8th and Saturday December 9th came in on the front end of a major change that brought the first vestiges of winter to the Foothills and Western Piedmont.
Due to ridging along the west coast of North America and blocking in the open Atlantic Ocean, a strong trough developed in the eastern half of the country at the beginning of the week…much like our forecasters hinted at in the original Winter Outlook back in October. That sequence of events really set the stage starting on the morning of December 8th as low pressure was developing along the Gulf of Mexico, meanwhile abundant moisture was established due to a prior frontal passage early that week. The passage allowed moisture to begin interacting with cold air. The end result was a significant winter storm.
Snow and rain/snow mixed overspread the region early on that Friday morning (pre-daylight) and by early afternoon everyone with the exception of the far southern tier of the coverage area was dealing with accumulating snow with temperatures at or just above the freezing mark.
The event lasted through Friday night before ending around lunchtime Saturday the 9th as additional jet stream energy accompanied the storm.
Snowfall total ranged from 1-3 inches along the US 74 Corridor with 4-8 inches on average along Interstate 40. The highest totals naturally occurred in the northwest sections of the viewing area right along the Blue Ridge, totals in a few spots exceeded 10 inches. The snow was followed by a brief cold snap that lasted a couple days.
#1: The wild, wild month of October
There is not a whole lot up for debate as to what the top weather story of 2017 is…it’s the multi-faceted dealings that everyone had to embrace in the month of October.
Heavy rain and severe weather was the calling card for the month as we have two main weather events with some minor storm systems caught in-between. By the time October was finished parts of the coverage area received near record amounts of rainfall but the bigger story was the two significant tornado outbreaks that occurred in the heart of the area.
The first big player in the month was was spawned due to late-season tropical development in the Gulf of Mexico. Hurricane Nate made landfall on the 7th along the northern gulf coast and its remnants moved into the interior southeast. That generally spells trouble for our part of the world and sure enough it did.
Nate spread heavy rainfall into our foothill counties where 1-3 inches of rain was common. But ahead of the main rain shield in some unstable air, tornadic thunderstorms moved northward from Lower Cleveland County up into the Foothills of Burke and Caldwell Counties. A total of three tornadoes were confirmed with two of them being EF-1 strength.
Then roughly two week’s later, on the 23rd a second (non-tropical) system produced a bigger severe weather outbreak for many of the same locations hit during Nate. The pathway from Cleveland and Lincoln Counties up through Burke, Caldwell, Catawba and Alexander was hit hard, as many as four more tornadoes were reported, three of them rated EF-2 on the enhanced fajita scale. Places like Lawndale, Toluca, Connelly Springs, Hickory, Sawmills and Taylorsville were impacted repeatedly.
The twin tornado outbreaks set records for confirmed tornadoes in the month of October in several counties inside of the coverage area…
Honorable Mention: January 22nd Mid-Latitude Storm:
A very strong non-winter like storm developed across the Southern Plains on the weekend of January 21st and 22nd of this year. The upper energy moved across the Southland and eventually morphed into a stacked inland wind and rain maker.
Usually big January storms yield winter weather but with mild weather at the time, heavy rainfall was the big producer as a sub-990 mb surface low develop over Northwest Georgia and pumped warm, most air into the region. On the 23rd of January the storm slowly weakened and began to move up the spine of the Applachians sending heavy rainfall up the east coast.
Those events along with other localized weather occurrence all yielded a very active 2017 for our weather team and for you, the follower. Hopefully 2018 will bring a more peaceful time in the weather world...