It’s a beautiful day outside today, with lots of sunshine and temperatures that are approaching 70 degrees. If this taste of spring is putting you in a mood for the weekend so you can get out and enjoy the weather … don’t get your hopes up. Unfortunately, today is not a precursor of things to come.
This weekend is going to be wet across all of Tennessee — potentially very wet, with heavy rain and maybe even some flooding problems.
The National Weather Service’s current rain forecast (pictured above) currently puts the bullseye for the heaviest rain totals directly over the northern Cumberland Plateau, with more than five inches of rain expected through the weekend.
A look at the NWS’s forecast for Oneida is a gross one: A 50% chance of rain on Friday, a 60% chance of rain Friday night, a 70% chance of rain Saturday, an 80% chance of rain Saturday night, and a 90% chance of rain on Sunday.
Rain chances will continue through Monday, as well.
Unfortunately, all that rain will lead to the potential for some flooding. Here is the text from a Hazardous Weather Outlook published by the NWS Wednesday morning:
Periods of rain, some moderate to heavy, can be expected from Friday through Monday. There is a potential for widespread flooding as several inches of rainfall are expected through the weekend.
Here is the setup: Today’s warm temperatures will be short-lived as a cold front moves through the region tonight. The air behind this front won’t be very cold, and the front won’t have a lot of moisture associated with it, but we’ll definitely be cooler tomorrow than we are today.
The frontal boundary will hang up to our southeast, allowing it to interact with a developing atmospheric trough that will result in widespread rain chances Thursday night and Friday. As the trough moves out of the way, the floodgates will open from the Gulf of Mexico, allowing a deep surge of gulf moisture to stream northward into Tennessee. This will create a very moist atmosphere, and a warm front is expected to push through the region on Saturday before stalling out just to our north and helping to serve as a catalyst for heavier rainfall.
Then, on Sunday, perhaps the heaviest rainfall of all moves through the region as another trough develops to our north. Finally, a cold front will swing through the area and push rain out of the picture.
In a forecast discussion this morning, the NWS notes this:
While this will be over a period of 3-4 days, locally heavy amounts in saturated areas over a shorter period of time could cause significant flooding problems by Sunday as the surface front gets closer to the area.
There’s still some uncertainty about just how much rain will fall. Models haven’t been very consistent. For example, will Saturday be a complete wash-out, or will showers be a bit more scattered in nature? Just how heavy will the rain be on Sunday? These are questions that might not be resolved until we’re actually seeing rain fall. But the bottom line is that multiple rounds of moderate to heavy rain are possible, which is going to create some potential for flooding issues by the end of the weekend.
After that, we should get a break from the rain before the next storm system moves into the region the following weekend.
There are still no cold temperatures or wintry precipitation showing up on the horizon for the next 15 days. In fact, Tuesday morning could be the only time we get below freezing for the next 15 days, based on current projections.