Quick-Hitting Winter Ahead For Johnson County And The Southern Appalachians
Issued Fri. Oct 1st, 2010
Coming off one of the coldest and arguably (only because records for Mountain City are less than ideal before the 1980s) the snowiest winter ever recorded in Johnson County, what does the winter of 2010-2011 hold?
First, let’s go over some of the big drivers in this winter’s forecast.
1.) LA NINA: A moderate La Nina is currently on going across the globe and this will be the single biggest factor in driving our winter weather this year. La Nina is simply a cooling of waters in the equatorial Pacific. Now no La Nina is like the other, so it’ll be important to focus in on the potential that our La Nina begins to fade during the latter half of the winter. This would spell a colder and snowier picture, whereas a strengthening La Nina would lead to a much milder, less-snowy, end game to the winter.
2.) WARM WATER CLOSE TO HOME: Water temperatures are running 3-5 degrees (fahrenheit) above normal along the Gulf of Mexico and just off the southeast Atlantic coast. As we progress into the later fall and early winter months this abnormally warm water will serve as a magnetic pull in drawing colder air masses south, and rather rapidly. With the rapid transition of the chilly air south, it’ll have less time to modify, resulting in a potentially cold early start to the season.
3.) DRY, DRY, DRY: You, the viewer, can go back and look at our Summer Forecast (still left up below) and see our worries of the drier than normal summer that was expected across the mountains. Sure enough, we’ve dealt with exceptionally dry conditions through the summer. Drought usually breeds drought and with a moderate La Nina on going, this “usually” isn’t the best news for drought-busting moisture across the southeast region, as a whole.
4.) NAO FORECAST: The North Atlantic Oscillation index is the “wild card” in this year’s winter forecast. Mid and long term modeling is all over the board, and the current water temperature profile doesn’t tip me in one way or another. With that said, I would expect the NAO to go through periods of negative (colder temperatures here) and positive (warmer temperatures in our neck of the woods) phases, in what looks to be a variable state for the ’10-’11 winter.
What does this all mean to me? After all, that’s the reason you’re here, right?! The 2010-2011 Winter looks to feature some wild temperature swings, especially through the early and middle portion of the winter season. There is the chance that we get off to a fast start with this winter season, with late November into and through December looking potentially cold and stormy. This can be thanked to the warm water temperatures “close to home.” That said, the middle to end of the winter season may not feature as much cold or snow (compared to normal), if our La Nina continues to strengthen.
An average winter here in Johnson County produces just a “hair” short of 30 inches of snowfall in Mountain City. Typically, average seasonal snowfall is closer to 22 inches for far southeastern portions of the county (around Watauga Lake), whereas “prime” upslope regions of the county (ie, along the NC state line) see average snowfall between 40-50 inches in any given season.
Bill’s official MCWC forecast for the 2010-2011 Winter Season paints slightly less than average snowfall (a stark contrast to last year’s record-smashing snow season), along with slightly warmer than normal temperatures. This is based on the idea that our La Nina remains the same strength or strengthens slightly during the “meat of the winter.” This would lead to snowfall on the order of 20 to 25 inches for “most of the county,” including Mountain City, Shady Valley, Doe Valley, etc. Amounts of 15 to 20 inches for extreme southeastern portions of the county, and amounts of 30 to 35 inches for prime upslope regions. After a cold start, a milder middle and latter portion of the winter should have temperatures, as a whole, slightly above normal. Temperatures should run half a degree to one degree on the plus side of normal, for the winter as a whole.
- Bill’s Bullet Points For Winter 2010-2011
Cold and wintry start to the season.
Milder and less snowy “meat of the season.”
20-25 inches of snowfall for Mtn. City
Temperatures run .5 – 1.0 degrees above normal.