Carvers Gap

Haha, true Reb. I was like, "What the heck?" when that next slide hit. I have an old rule that says when a strong cold front drags its feet along the Gulf, that tends to allow for cyclogenesis. You can watch that front hit the waters of the Gulf, and immediately moisture flows north. A word of caution w/ that setup, and have been shafted many times by this scenario...if that develops(assuming real) convection along the Gulf, it will stop the moisture feed north. I don't trust the Pacific feature feeding in, BUT(and this is a big but) the synoptics with this run used the Gulf feed scenario which is more plausible. Still, it is the GFS. However, the GFSAI got to a similar place. If the Euro AIFS continues to have it, that would be incredibly encouraging.

haha...and boom, there it goes. Putrid it is not. Gulf feed this time w/ some Pacific feed which I think is sketch.

The 18z AIGFS actually has that connection but w/ the Gulf. I do think there is a better than decent chance the GFS is on to something in regards to the 17th system tapping subtropical moisture - more likely a Gulf feed. The 18z GFS is pretty putrid, but it wouldn't take much for that to be stronger. Interestingly, the 12z GFS run just looked really amplified from the word "go." We have seen that from the GFS since November, ie a really bad tendency to over amplify all features on the map. I have to think there is a programming change for that to keep occurring. This 18z run looks a little more realistic.

The 18z GFS will unlikely have the big storm on the 17th as the cold front is not ingesting a tropical system from the Pacific! Haha. Still, I think we see some light snows traversing some portions of the forum. edit: Although, there still is Pacific feed to the Southwest of the front.

The AI Euro hasn't been terrible this winter, especially w/ surface features.

There should be snow in the air as early as tomorrow for areas north of I40 and Nashville eastward.

Haha. You all know I am not using chatGPT, because there are so many auto-correct spelling errors or careless errors. If those aren't present, I have been sucked into the singularity and there needs to be a well check.

The Euro deterministic didn't look terrible. Indeed, its ensemble is much different than other ensembles, BUT has trended towards the other cluster of ensembles (eastern intrusion of BN heights after the 20th) since yesterday. That tells me the EPS is probably still correcting. FWIW, the EPO ridge appears to have some staying power. I think the spacing and timing of the next three windows is incredibly important - 15th, 17th, and 20th. Amplified troughs will often over perform IMHO.

And also maybe 25-27th, but that may be getting over my skis at that range....but the ensembles are honking right about then.

I am also now watching Jan 20th as a window a bit more closely. Looks legit.

....and put the two together.

Yeah, the GFS and AIFS Euro are two models I would say that I don't trust that much! The ensembles have been decent so fare this winter though. I just thought they were some fun slow maps, but do show a storm track that I thought was interesting. Need the Euro on board at some point, but it may be slow to get this as it seems it was slow to get on board w/ something(can't remember) earlier this winter or late last fall.

Some fun ensemble members from the AIFS EPS and GEFS. BTW, the GEFS has been spitting out big dogs for about 3 runs - holy moly.

The 6z Euro AIFS has this scenario but just not on the GFS juice. Honestly, this run of the GFS looks like someone poured a little hot sauce in the programming at 12z. Threat looks legit, but spacing is key. The NE is probably gonna get hammered. Still details to work out at our latitude but a fun run! The GEM is less enthused. Let’s see if the Euro has this.

West Virginia is up to 47” at 232. @tnweathernuthas 26” of snow to this point.

Second storm is La boomba.

The 12z GFS looks like an inland runner or lee side low which develops and causes lift over E TN 10-12” over TRI and much more in the mountains.

From MRX, and when I read about Cove Mountain...I always think about @Math/Met Wind: With the 850mb jet pushing north into the area later this morning, wind gusts will increase across the higher elevations of the east TN mountains. Wind gusts from 35 to 40 mph will be common from around 12Z through 18Z. Latest HREF probs not too excited about reaching advisory criteria, with only isolated areas of 30 to 40% probs. Cove Mountain will most likely see a 40 to 50 mph gust during this time, but most areas will likely stay just below advisory criteria. Winds then pick up again behind cold front tonight into Sunday, with northwest flow around 30 to 40kts at 850mb. This will be another period where near advisory level gusts will be likely for the higher elevations of the east TN mountains. A Wind Advisory may be needed with the next forecast issuance. Storms: Nothing has changed too much with the severe threat. Instability continues to remain elevated with only very low probabilities of some SBCAPE later today just ahead of the cold front. With surface based CAPE unlikely, the main threat will continue to be isolated damaging wind gusts with any stronger shower or thunderstorm. Tonight into Sunday morning, additional moisture moves in with the trough axis and any precip should mainly be in the form of snow. Light snow showers are probable across portions of northeast TN into Southwest VA. No impacts expected as snowfall amounts will be very light if any. High pressure then builds in Sunday into the new work week, with a period of dry and cooler conditions through Tuesday. Downstream from a amplified ridge over the PNW, troughing will deepen across the Ohio and Tennessee Valleys mid week. The return of moisture and cold temperatures may lead to light snow accumulations across higher elevations of the east TN and southwest VA mountains Wednesday night into Thursday. High pressure then begins to build back in on Friday and into the weekend with moderating temperatures.

Kind of a medium to long range update. Thankfully, we have some nickel and dime stuff to track in the shorter range. Just looking at the app on my phone...real feel temps should be in the upper teens by this time tomorrow. Quite a big change incoming. LR modeling did a decent job w/ the 500 pattern for this. Cold air will arrive about 12 hours ahead of what has been modeled as a transition timeframe for several weeks. We will likely roll a ridge through Jan 21-23, though that is not set in stone. The 6z GEFS is very aggressive in keeping the eastern trough in place. The 6z AI EPS gives us enough of a cold air tap that should be serviceable. I think the idea that cold dives into the Canadian Prairies and then rules the roost...that looks like a plausible if not probable idea as of now. Part of the TPV being trapped over NA by HL blocking also looks likely. Sneaky important. They key is going to be the cold being centered over NA and not retrograding into Canada. Most ensembles have the cold in the Canadian Prairies, but the Euro is more retrograded into the Yukon. A good blend is the 0z GEPS which looks about right to me at 500.

The 6z Euro AIFS has a decent snow mean. Models are all over the place w/ the track placement of coastals right now...so huge grains of salt. I would think eastern areas of the forum and the Apps have a shot at coastal enhanced snows w/ clippers up for grabs by everyone. The coastal storms will largely dictate the clippers which follow, and if they can get to our latitude. Remember, clippers generally trend sharply north at the last minute. So, we want them south of us on modeling. As for the coastal opportunities themselves, they are still a bit too far to the east, but...the northern stream interaction w/ the southern stream may still accentuate snowfall over areas of the forum which are favored by phasing or partial phasing of vortices. I would suspect a northwest jog w/ phasing, but that rule sometimes doesn't work out as modeling often under estimates blocking and cold air. As Holston noted yesterday, models are exiting the 5-7 day window where they will lose storm intensity for storm 1. I would think during the next 24-36 hours that we see some more fireworks along the coast w/ phasing.

Ya'll need to see where the 18z GEFS ended its run...nice trend. We saw that once or twice yesterday, and now it's back.

I grabbed a couple of these from CPC...the MA forum has also posted these.

Powell, I hate to hear that. Hang in there.

The Euro Weeklies this afternoon definitely support that CFS MJO map. Get a good window from say Jan15-22nd-ish. Then, we roll a ridge complex through to end the month, then do it again to start February. The interesting thing will be if the cold can actually retreat or if it gets trapped under a HL block. The Euro control had the EC cold throughout the run. Just kind of seems like it is going to be difficult to push the cold out of the pattern for long periods of time, but I could be wrong! Ripe, ripe, ripe for an ice storm if we push a 500 ridge into the SE but the surface doesn't respond to the AN heights, ie stays cold.