Today
Happy Cinco de Mayo everyone!
We are sitting pretty right now, between the core of low pressure and the bands of rain wrapping around the system. Keeping us dry for now…
Infrared Satellite Imagery (yellow and blue high cold cloud tops usually rain):
This afternoon we thought the rain — which moved east — was going to stay east. It hasn’t.
At 7:27pm, light rain showers crept northwest across both counties:
Why is this happening? This satellite image (from 7:15pm) explains:
April postcards from Old Man Winter are common, but this May postcard has been waaaay out of bounds.
That said, you’ll like what we have to say about the rest of the day.
Today
At 11am the rain rope (“rain shield”) was sitting along I-65 and very, very slowly moving east at around 15 mph. It’s also way too chilly for May: 46 at 11am.
A Flood Watch is in effect until 7 am Sunday. Here’s an official graphic:
It’s going to rain tonight and into the overnight hours. The ETA for Williamson, then Davidson, Counties is between 8pm and 9pm tonight. Follow along on Twitter for more frequent and detailed updates (@NashSevereWx).
Whoever is doing the rain dance, did it right! Blame a “cutoff low” spinning in the middle of the country. It should rain out most – if not all – of the entire weekend.
So what is a cutoff low? It’s a low pressure system that has been “cutoff” from the flow of the jet stream (upper level winds) which push weather systems around. Since the low pressure system is cutoff from what steers it, it will just meander over the next few days, sending waves of rain our way. Until another system comes along and shoves it into the Atlantic Ocean, we are stuck dealing with it.
They say when it rains, it pours, and that is exactly what we have in the forecast. Rainy day after rainy day.
Rain chances increase, starting this afternoon.
The Hi-Res NAM has spotty showers as early as today. Here it is Thursday 4 PM:
There’s a very small – almost unmentionable – chance of a stray shower tonight. If we get one, it shouldn’t be enough to rain us out. We’ll make it to 80.
A slightly better chance of a shower or thunderstorm. The best chance will be in the afternoon. Rain-out chances are low. High of 78.