Carvers Gap

Honestly, too many events to count on that run. Whatever you like, the 12z GFS was dishing it up. Been a minute since I have seen a run like that.

Well, that was a proper run, 12z GFS. One right after another.....

Interestingly for TRI, the airport made it to -21F just looking at records. The previous night was -16F. Those would obviously be all-time lows. The airport sits up on a knoll, and if memory serves me correctly, it didn't get as cold as other areas deeper/downstream in the valleys. I got to -26F in my local (southwest Virginia) with about 15mph winds(conservative estimate...drifts were 1-2')...so new scale would have me in the low -50s for WCs. NE TN got wicked cold. I have shared this before, but we were fixing pipes under my house in the middle of that. I also remember my dad putting a starter in our '72 Impala in the K-mart parking lot(now U-Haul). I have never been that cold since. Very rare weather set-up to bring a piece of the PV into the eastern valley. Interestingly, we have had some really cold wind chills during the past couple of years. Those wind chills would likely rival the mid 1980s. A good friend noted that we seem to be going below zero in the eastern valley a bit more after a long lull. Anyway, great conversation and a fun walk down memory lane. That all time record low can stay right where it is. LOL.

The 0z Euro is what has my attention in terms of cold....that lobe over southern Hudson Bay rotates down into SW VA. I have seen this on a few runs now in one form or another. The Euro, with the exception of yesterday's 0z, has had many of the coldest solutions. One could make a case that the worst of the cold is over by the 9th. However, I wouldn't be surprised to see the 10th - 20th have one more reload of this. To be fair, this is an operational model and probably shouldn't be used for details at this range. This is just an example. Most ensembles are picking up on a fairly strong cold shot between the 7th-9th being displaced decently southward into the Upper South. I could be an issue for agriculture in Florida as well if that verifies.

Yes, those are the folks I am thinking of specifically. Those are hardy folks. I don't want to cause more alarm than necessary, but the scenario is there for it to get really cold above 2500'. It isn't anything folks in those areas haven't seen before, but in a camper...those are different circumstances than previous winters. If roads get icy for extended amounts of time(can't get to them), that is the main concern.

That is awesome, man. I talked to someone over Christmas(who repairs construction equipment) who said the roads are still in pretty bad shape in some areas. Crews are doing massive amounts(mind boggling how much they have fixed) of work both on roads and getting people into housing...but it is a big lift in those areas. Most mornings I see convoys of concrete trucks and gravel heading that way.

It looks like the timing of the first of several cold front is late on January 1. The GEFS is a few hours slower. After that, I think we we see a series of cold fronts(warmth surging in between each front for 1-2 days), and then cold returning. The EPO ridge is in a place where it can deliver very cold air. Right now, the 0z Euro is the coldest. The ensembles aren't warm. To be clear, I don't see 1985 cold air on the map. If we were to get snow on the ground prior to a cold front moving in, I would imagine below zero temps would be possible and even probable in some locations. Real feels could be rough with a couple of these cold fronts. I think the potential is there for the cold to run from Jan 2nd to roughly the 20th. Then the trough tries to work back into the Mountain West. I know many are saying the game is up by then. That might be correct, but cold is somehow (assuming the upcoming cold verifies) finding its way into the East against some pretty stacked analogs(though a smaller cold analog group exists for January which is completely opposite of the warm analogs). If the NAO were to fire into February, it isn't unthinkable that the cold moves into the Mountain West and still manages to find its way eastward. Some Weeklies ext runs are showing that. It is always possible or a reversal on modeling. That seems to have been the norm during the past few years. However, the first cold front is well within range now. Even on the Apple weather app, the first cold shot is present. So, the cold is just on Weeklies maps. It is within ten days. Counting today, we have about five more days before the cold returns.

In my mind, it doesn't take much of a jump to get to a point to where we see an overrunning event such as ice due to WAA and cold air getting trapped in the eastern valley and then followed a few days later by an ana front. We could end-up just with dry cold, but there is a decent amount of energy in that northern stream along with WAA attacking periodically retreating cold air.

The 0z Euro has a very strong Arctic(?) front later in its run. It has had this pretty consistently for the past few days. I am sure agencies in the areas working where Helene hit are starting to prepare - sources for heat, warm clothes, food, and temporary trailers winterized. Transportation in many areas is still an issue.

Great info beavis, John, and Boone. We had 1-2’ drifts from that in Scott, Co, Virginia. The wind chills with that front in SW VA were insane. I don’t want to embellish, but maybe in the -50s? Our farm thermometer got to -26F.

I suspect the GFS woes from late last week were probably due to that model mishandling the MJO. The Euro Weeklies tonight should be interesting as the 0z run was very cold and didn’t have the PNA displaced into the Plains as yesterday’s 0z did.

Overnight model runs and 6z continue to paint a pretty cold picture over our region to begin January. Interestingly, the cold appears to have moved up to late in New Year’s Day. Instead of Jan 3. Though details are murky for individual events, the CMC has a pretty stout upslope event well inside of d10. Let’s see if that shows up in other modeling. The 6z GFS has brought back the slider for Jan 2. No other model has that…so proceed with caution.

Might have been a phaser where he was racing the northern stream in from St Louis? I normally don't use the CMC weeklies a ton, but I do look at them from time to time. Sometimes the CMC is the only model which can really handle very cold patterns. It does have a cold bias, so maybe scale that back a degree or two. GEFS ext is taking forever to load tonight.

Finally figured out how to make a tweet work. Just copy the twitter link, past it into notepad, change the x to twitter, and copy link into post - will automatically update. MA had shared this. Now, we certainly don't live in the Mid-Atlantic...but E TN and NE TN do sometimes cash-in on the beginnings of their storms.

I think in 2018, the issue was the EPO got so tall, we were just pulling cold, dry air from the Arctic. Modeling this time does hint at multiple short waves coming out of the northwest. These look like 1-2" quick hitters. I know you know this, but for others new to this.....in very cold air those shortwaves can have 15:1 or better rations. Was 84-85 northern stream driven? I was a high schooler at the time, and wouldn't have known the answer to that. It seemed northern stream driven as my dad was hauling a load from Missouri to Tenn. He was racing a massive snowstorm home - barely made it. He got the rig into to town, jumped in the care, and rolled in with about 4-6" of snow already on the ground. In my mind, that storm came from the northern Plains....

This is a 360 map from the Euro AIFS - proceed with caution. It was super warm at 0z, but has rapidly cooled off. This is 12z. We will see what 18z has in a bit. It ended with a setup that was sending and Arcitc air mass straight down the middle of the Canadian Prairies - due south. I think we are going to have some northern stream smaller systems and maybe we get an STJ system. Clippers appear to embedded in this. I will add(very cautiously), sometimes BN precip can reflect snowfall areas...and sometimes it is just dry. With this type of look as a potential...no way modeling has the details even remotely worked out. That is confluence over the Tenn Valley right there. Northern MS to DC would be happy with that setup and 200 miles either side of that line IMHO. We'll see.... Dig up some great snowstorm maps. Looks a lot like that.

I don't know if this January is that time, but one day we are going to track another memorable pattern and maybe historic pattern. That is why we show up each winter. Give me that above, and let's roll. We need the Euro to stay in the fold overnight!

Still rolling.....EPO, NAO(but slightly east so no WAR), trough east of Hawaii(important). Anyone have any daily PDO numbers? I heard it was approaching neutral last week. That look right there opens up the potential for the PV to be trapped.

Man. Can you draw it up any better? This is the 18z GEFS. The Weeklies from this morning looks almost exactly like this as well, and is out to 1/15.

I am going to use the GEFS ext weeklies today since the 0z weeklies were so wonky(back to normal at noon...so hopefully not a trend). The 0z runs are what the Weeklies are derived from. So far, the GEFS ext is about halfway out....frigid for Jan 7-14 and colder than yesterday's run.

GFS Happy Hour rarely disappoints.

It will be interesting to see how things play out. Both the 12z Euro and GFS have multiple events ranging from small to boomers. The Euro has a slider and an anafront. The GFS has 2 sliders and the fantasy land big dog. I would look for some snow in he air by the 3rd or the 4th. For me in E TN, this definitely looks like a nickel and dime pattern...but the 12z Euro gives me a bit more confidence this pattern will deliver at some point. It really is going to depend on confluence. There is some 14-15 in how this looks. Lots of small pieces of energy rotating through the northern stream as the EPO really locks in.

Last nights Euro/EPS was strange. The multiple runs before it and the 12z run after it - not the same. Had to have been some model input or a week. The 12z ensembles are about as cold as you can get at this range. Big signal for a very cold air mass. I am like Bob Chill in the MA...just give the cold, and let's roll the dice so to speak.

Real feels are in the -10s for NE TN late in the 12z Euro.