It’s been a while since we’ve done some Meteorology 101, so let’s have some fun!

First of all, to get a BIG snow we need:

1)  A well developed low pressure center passing to our south or southeast.

2) This has to happen with cold air in place.

We are going to get the first part.  It’s the second part that may lag behind keeping us from getting a big snow, but still allowing some flurries and snow showers.

The maps above are from a computer model called the GFS.  The top panels are forecasts of the surface isobars for 6am Wednesday and 6am Thursday.  The bottom panels are the corresponding forecast of the precipitation for the 6 hours ending at 6am Wednesday and Thursday.  The bottom panels also have a black line that is the forecast of the freezing line for 850 millibars (or about 5,000 ft.).  This is often (but not always) where the rain/snow transition is.

In the top panels, you can see our Gulf Low bringing us copious amounts of rain on Wednesday when that black freezing line at 5,000 ft. is well to our northwest (we’re on the above freezing side).  By Thursday morning, the low is well past us, and the black line has pushed to the Smokey Mountains (now we’re on below freezing  side).  If you are one hoping for that big snow, unfortunately the colder air comes in after the low has passed us.  However, there still will be enough leftover moisture (along with an upper level disturbance) to cause some snow flurries late Wednesday night through Thursday morning.  If the two could have been more in sync, we could have seen 3″ or more.  This is something we will be watching for as we head through winter.  For now, enjoy some flurries if we get them.  The chances increase the farther east you are in Middle Tennessee.

The rain looks pretty solid overnight through the early morning hours of Monday with many areas seeing around .25-.50″ of rain.  Some of our southern counties may even hear a few rumbles of thunder.  The colder air is returning, as well.  We expect to start off with temps only in the low to mid 40s, and only reach the upper 40s for highs.   The rain should push out fairly quickly Monday morning, but the clouds may not erode away until the afternoon.

In the 7 Day Forecast, a Gulf low will bring a good chance for rain on Wednesday.  That rain may end as some snow flurries on Thursday.  We will keep you posted.

As mentioned below, showers pushed into Middle Tennessee earlier than anticipated today.  The large round of rain will still arrive later tonight between 10pm and midnight, and hang around through Monday morning as colder air pushes back in.  Our low will drop to the mid 40s by daybreak, and then never get any higher than the upper 40s on Monday. 

By Wednesday, a Gulf low should bring a large rain chance.  As that low passes to the east, a secondary front will bring some of the coldest air of the season our way and that could yield some snow flurries late Wednesday night and on Thursday, especially from Nashville eastward.

Weather forecasting will keep you humble.

Yesterday, we said that the rain would hold off until tonight.  Indeed, there is more rain coming  in tonight, but an early round of showers pushed in this morning and will be around for a few more hours. 

The good news is that it looks like the showers will be tapering off in Nashville just around kickoff for the Titans game at 3:15pm this afternoon.  Unfortunately, that doesn’t help out the tailgaters trying to enjoy the outdoors before the game.

Tonight’s rain will be around through Monday morning.  Skies will be clearing out during the afternoon, but it will be considerably cooler with highs in the upper 40s to near 50.

In the long range forecast, we still expect a big rain chance on Wednesday, that could end as snow flurries late Wednesday night through Thursday.

Good news for the Titans game.  Although it will be cloudy, it looks like the rain will hold off until after the game is over.  Our counties to the west near the Tennessee River could see some shower activity during the afternoon.  Temps will remain mild for one more day reaching about 63 for a high.  Then the bottom drops out again on Monday with highs expected to only be in the upper 40s with morning showers giving way to afternoon sun.

A Gulf low should bring us a big rain chance for rain on Wednesday.  As colder air spills in behind that low, we could see a few flurries late Wednesday night and Thursday morning.

Wow!  68 degrees on the Saturday after Thanksgiving.  That’s pretty nice.  By the way, the record is 73 set in 1998 and in 1990. 

Tonight will be cool, but not as chilly as last night with temps dropping into the low 40s by daybreak (some upper 30s in eastern counties). 

On Sunday, the clouds will be on the increase out ahead of a cold front that will push in Sunday night.  It looks like the rain will hold off until after Sunset on Sunday as the front approaches.  With skies becoming mostly cloudy, temps will not be quite as warm as Saturday, but we should manage about 63 for a high with a southwesterly breeze at 10-15mph. 

The rain will hang around Sunday night through early Monday morning as colder air pushes in for Monday.  The sun should reappear Monday afternoon, but highs will only be in the upper 40s.