Sunday Story and the Forecast
–A nice Sunday in store for us
–Heavy rainfall expected this week
–Strong storms may accompany Wednesday’s rainfall
–Heavy rainfall will once again threaten the region this week. Please be careful around any flood waters. Total rainfall this week total 4-6 inches across the plateau, with locally higher amounts possible. A flood watch is in effect for tonight through Tuesday for southern regions, with more flood watches likely for all of us as we go through the week. Even this current watch could be extended northward at any time. In addition, strong to severe storms my threaten our region on Wednesday, along with additional heavy rainfall.
Below is a map from the Storm Prediction Center (SPC) outlining a severe weather threat area for Wednesday. The SPC doesn’t outline threat areas that far out unless they have high confidence in such storms. Notice the greater threat is to our south, which is typical for this time of year. With our saturated soils it won’t take much wind to take down some trees and that could lead to power outages. This event may be quite similar to the one we had last Tuesday.
Look for clouds to be on the increase today, but we should stay dry through the daylight hours. The rain develops tonight and then sticks with us through at least Thursday morning.
Rain this week will be heavy at times. If you’ve already had flooding issues you’re going to have them again this week.
Storms on Wednesday may pack a punch. Any wind that comes out these storms will easily topple trees in these saturated soils. I think it’s safe to say we ought to prepare now for some power outages. I’ll keep an eye on that.
We dry out at the end of the week.
Baldwin’s 7-Day forecast
The International Space Station will fly over this evening at 5:52, but clouds will likely prevent a good viewing. I’ll send out a reminder later if those viewing conditions turn out to be better than expected. At 5:52 it should appear in the west, northwest and disappear six minutes later in the south, southeast.
The temperature at Moran, Wyoming dropped to 63 degrees below zero on this day in 1933. That established a new state record for Wyoming. In neighboring Montana, the temperature dropped to 66 below zero, establishing both a record for that state and for the nation. That national record would stand until 1954.
Clouds and the Plateau
As many of us know, the elevation of the Cumberland Plateau makes a big difference in our weather. Just drive from Knoxville to Nashville on just about any given day and you’ll know exactly what that means!
I’m often asked, “Why is it always so cloudy on this mountain?”
Winds in this part of the country are often from a westerly direction. That’s the direction the wind blows from most of the time. That means winds commonly come into contact with the plateau along our western edges.
As those winds reach the plateau, the air within those winds is forced to rise up the plateau. Since temperatures decrease with height, the air cools as it rises. The atmosphere is layered in such a way that the warmest temperatures are near the ground and get colder the higher up you get.
When air is cooled, it condenses. This is why we have dew in the cool mornings. That air cools down and saturates. The same is true when air rises up into the colder atmosphere above.
That cooling and condensing can lead to cloud development. This can create those cool, cloudy days in the winter time.
As the same winds that rose up the western edge of the plateau move off the eastern edge of the plateau, they are forced to sink into the valley of East Tennessee. Conversely, as rising air cools and condenses, sinking air warms and dries out. That can lead to sunny days in Knoxville, while we are covered in clouds on the plateau.
So, the next time you’re driving back home from Knoxville or Nashville and you look ahead and see clouds over the plateau, you’ll know why! Just be thankful those clouds also keep us cooler in the summer!