Carvers Gap

I know it is a bit out there, but I really like the timeframe just before March 10th. Ensembles have very cold temps incoming again around March 7th. The EPS has temps 10 degrees below normal. The GEPS and GEFS are 3-4 degrees colder than that. That is prime climatology for an early spring winter storm to boot. Looks like maybe warmup next week between say Tuesday and Thursday before temps go back to being BN. This is kind of a back and forth pattern being portrayed which is more cold than warm. It is pretty crazy that we set 1-2 record highs to start the month, and it is snowing today after severe weather and flooding. That is not as uncommon as one would think. IMHO, the pattern until it says otherwise is intrusions of warm air masses into a colder pattern. At some point spring will appear, but winter may hang on for a bit into early spring.

Just digging back through overnight runs, the 0z GFS was pretty epic. I like the GFS about this time of year as it handles the dynamic of an approaching new season better. Short version, it is better during shoulder season. The GFS is loaded, even during bad runs....lots of incoming systems and cold. I do think we see some warmups, but tons to track at this moment. This looks like a pattern where higher elevations get hammered and lower elevations of NE TN, SE KY, and SW VA get some surprises.

Really nice pattern projected by both the MJO, ensembles, and some deterministic runs. The MJO looks like it may stall in the cold phases - that is becoming more likely but not certain. Ensembles keep the trough over the eastern US for the foreseeable future (maybe through March 10th or so). The pattern is active with a lot of northern stream vortices in play. It is late season, so like today, we need things to be a little more Goldilocks - just right. However, I think NE TN, which has had less snow than many, may well cash in on a few more events. Again, modeling is finally seeing the MJO influence.

Maybe an inch of snow IMBY. Snow looks like it is dissipating quickly over the region. We might get another little bump later in the morning. Tonight is what I have been waiting on. It won’t be a ton, but Arctic fronts can do weird things during Feb.

I think this Arctic front is going it have to be reckoned with in NE TN tonight and the northern Plateau. Frigid temps and IMO over performs in many areas due to the cold ground.

This gets my attention.

That 18z GFS is straight load up. That looks like an MJO that is stalled in the cold phases. That looked a lot like 14-15...just a shade warmer maybe. Modeling is seeing the MJO now. Some modeling was completely blind to it during December. Then, it flipped overnight. Now, we see a repeat.

18z GFS puts down 5-6" over NE TN. I don't know if it is right, but that is the kucher output.

Anyone want to take about today's MJO plots(plural).

Nice little 12z suite today.

The 18z RGEM just ran. Good chance the mountains eventually are upgraded to WSW or WWA. MRX is either not including the upslope event which follows or doesn’t believe it will happen. February systems tend to have a bit more juice. Time will tell.

I don't know if this helps, but when I walked out this morning, the top layer of ground was frozen pretty solid. I saw ice crystals growing in the mulch. With the very cold winds today, cold temps tonight, and chilly day tomorrow, I think snow could accumulate decently if rates are good(not great but good). If ground temps were crazy warm, there would have been no dusting of snow in JC this morning. We had snow on some of our rooftops here. It looked like it was pouring snow at higher elevations.

Don't sleep on Sunday. The 12z GFS has snow for higher elevations. Other models don't have it yet, but February precip patterns would allow for a marginal event. And can we get some of this please....a loop in 8? That is the BEST case scenario. I think this thing moves through colder phases and is into warmer phases by the 10th. But if the below is true....winter is gonna hang on for a bit.

Nice improvement by the 12z Euro.

I like watching the GFS around this time frame as it will often catch trends before other globals. It has been pedestrian at d8+. Once inside of d5, it has been solid.

The 12z GFS is pretty healthy - bumped up totals. Maybe we are seeing modeling see the Feb strengthening that January isn’t known for. I am not even remotely ready to give up on system one. I think time of day will limit system one…though north Johnson City has snow on the ground as we speak. I think upslope areas will do better with the second system.

That is what it is. I think NE TN will get as much or more from it. The 12z has the same. Slight tick north.

I do wonder if the Euro is having feedback issues over the Gulf. The RGEM is what is I am going to roll with on this one - I think. It and the GFS have been good in the short range this winter. They have barely budged for days.

With the exception of the NAM and Euro, most models over NE TN increased last night. I do want to see some improvement from the Euro though. The NAM....has been really bad IMBY this winter. The RGEM has been good. I would think maybe to half the totals of the RGEM and seems maybe right. 2-3" as Holston noted....some of that will need to fall the evening after the storm when sun angles are low.

The 0z and 6z RGEM has bumped up totals over NE TN as it has a second round of snow w/ the NW flow event. 4-5" totals. We'll watch it for trends.

And time of day along with marginal precip is usually not a great recipe for decent snow IMBY. We need this to overpeform.

And you can see why NE TN kind of backs into decent totals with that jet streak right at the end. I do think that trailing system will be good for some.

There are two main drivers which are causing this to lose precip. The main one is the convection along the GOA. The other is that the system is not a Miller A. It is a true slider now. So, the flow doesn't back over the eastern valley as it did in earlier runs. Very La Nina-esque pass by this system, and something we have seen during several of the last winters due to so many La Nina's. There is a reason that climatology favors middle and western areas during Nina events - Apps runners or sliders which lose moisture as they traverse the state. I do wonder if we have one more card to play. It is pretty common for modeling to under-model the qpf for a system during February. Let's see if the trend reverses(I don't see that reversal at this time). However, that reversal can sometimes occur as radar driven modeling adjusts during an event. Short term modeling is so good, that almost always at least one model catches that trend. Time will tell.

The 18z GFS has a Miller A on Feb 24th. I tend to watch the happy hour run for new trends. Something to watch .

GFS is really sticking to its guns keeping the snow/rain line down just south of the Tennessee border. Hopefully it's sniffing out the CAA better and warm nose less of an issue. The 18z GEFS has also trended south and bumped up totals.