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More Rain Today? Cooler Week Ahead, & Next Weekend’s Guess.

How Much Rain Did We Get?

A total of 1.06″ fell in the official rain can at BNA from yesterday’s rain.

Local CoCoRaHS observer totals in Davidson County:

And Williamson County:

Radar Estimated Storm Total Rainfall, which isn’t that reliable for raw totals, but it has a good idea of who got the most rain. Green is less than 1″ and yellow is more than 1″:

Will We Get More Rain Today?

Maybe a little, but it must be said NWS and weather nerds are…

…over the weather models, not just for today, but also for Tuesday.

This morning, a cold front sat along the Mississippi River.

This front will move our way today, and when it arrives after noon, it might set off some rain.

Here is where the weather models models disagree.

The NAM3 model only has scattered showers, where some get early/mid-afternoon rain, others get nothing:

The HRRR model is even drier, with only some seeing any rain at all this afternoon:

The problem is that the GFS wants to put down 0.1″ of rain around lunch, then another 0.1″ during mid afternoon.

And of course, the Euro believes the GFS. It’s also got a rainy afternoon.

And of course we can’t really rule out a thunderstorm or two, but I doubt we will see one.

Hence the frustration. Future prediction is hard.

So what should you do? Embrace the uncertainty, but don’t let it ruin your afternoon. The risk of severe weather is very low, almost zero today, so don’t let it stop you from doing what you want to do unless you’re a particular wicked witch or a gremlin and can’t get wet. There’s a very wet airmass overhead now (PWATs are at 1.41″, fellow weather nerds, with a few weak inversions at the surface and 800mb), and there will be some forcing to create rain this afternoon when the cold front arrives. So, I think we may see some rain, briefly, around early/mid afternoon, but not a washout. I won’t be surprised if we get nothing; it always bothers me to say it will rain when both hi-res models (NAM3 and HRRR) show so little. Embrace uncertainty.

All models agree the rain will be gone tonight.

Cooler!

Temps are forecast to be in the 70°s through Friday! Humidity will also behave, staying low, with no dewpoint forecast over 60° until Saturday.

Notice it’ll get much colder after a cold front passes through from the Tuesday/Wednesday rain.

Tuesday’s Rain Chance

The models are all over the place about rain chances Tuesday. Let me paraphrase from the NWS forecast discussion this morning:

Models are in AWFUL agreement. The GFS model thinks it’ll be dry until Tuesday night. The Euro model predicts showers and scattered thunderstorms into the mid-state Tuesday morning. The NAM model is throwing even a larger curve ball and bringing the rains back Monday night before midnight. Due to the inconsistent predictions from the models, but because at the GFS model has been consistent, I think most of the rain will come late Tuesday night into Wednesday, but I`ll increase the probabilities of rain slightly Tuesday to account for the uncertainty.

Translation: we don’t really know, but we think the most likely time for rain is late Tuesday night into Wednesday. Rain may arrive before then.

The Weather Prediction Center’s rainfall forecast from 7 AM Tuesday to 7 AM Wednesday thinks we will see about 0.25″ of rain.

I bet this will change.

The Next Weekend Guess

Temps Saturday creep over 80°, and humidity will rise as dewpoints poke above 60°. Pumping this much heat and humidity means we may see rain, that summertimey, pop-up stuff.

And then there’s the other thing to watch for this time of year: rain and storm systems coming in from the northwest. Medium-range models, especially the Euro, sends such a system from the Plains with a lot of rain and storms Saturday night into Sunday, but right now that looks more like a West Tennessee/Memphis problem than a Nashville problem. However, it’s way too far away for us to say, and if it does nail West Tennessee, we would probably also get some rain.

After all, if we can’t draw specific conclusions from the models today or Tuesday, why do so for a week from now?

If I had to guess, I’d say watch out for rain/storms Sunday and Monday of next week, but expect a change to this forecast as we go through the week.

Have a great Sunday, y’all.


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