Lead Forecaster Daniel Crawley
Good Saturday afternoon to everyone. We are stuck in a persistent warm, moist and stormy weather pattern across Western North Carolina here in early August.
You can say thanks to the pesky Bermuda High for keeping us in this pattern. Southeast flow off the Atlantic Ocean continues to pump abundant moisture into the atmosphere and with the southeast flow encountering the Southern Appalachians, daily thunderstorms are common. The high terrain, along with any residual outflow boundaries help spark storms in the afternoon hours and they persist well into the evening hours. This kind of pattern can even allow coastal sea breezes to penetrate pretty far inland due to the prevailing flow at the low levels.
This pattern is in no hurry to go anywhere as the Bermuda High is locked in for the next 4-5 days…looking at the 500mb pattern in the video below, things will remain the same though at least the middle part of the upcoming week. There are some subtle hints though of a change in the pattern toward the end of the current 7-Day forecast cycle as the Bermuda may at least temporarily lose its grip, a more influential ridge begins to take over across the Plains and retrogrades toward the Four Corners Region. If that does indeed happen, we may see an eastern US trough try to develop by late next week and that could help scour out some of the excessive humidity that has been stuck over the region in recent weeks.
Until we get to that potential pattern change, the mountains and foothills look to see the best rain chances under the Bermuda High setup…these storms are generally slow movers and they can put down a lot of rainfall in short order. Be mindful of that if you have camping plans along the Blue Ridge or possibly doing a day trip up on the Parkway and in the High Country…