Carvers Gap

The 12z GEFS does bump-up totals w/ system #1 on the 15th. I have less of an issue w/ GFS synoptics w/ storm one. Though for certain it still seems a bit too amped. Again, the 12z GEM looks suspicious w/ so little from a strong vortex. Hopefully, the Euro can give us a bit more perspective with the understanding it is often under-modeled at this range as a bias. I would use the NBM for right now for storm one.

And great avatar BTW!

FWIW, I do think the a coastal w/ the 17th front is plausible. I think the cold front driven snow is plausible provided the GFS drop the crazy PAC storm feed. So, I do think a front w/ a wave turning into a significant EC storm is very plausible.

I highly doubt there is precedent for Pacific tropical features (during mid January) feeding into a cold front over our area along the EC of North America. Webber mentioned yesterday(finally remembered my source) that it was a pretty awful job by the GFS. Maybe late fall that could happen? No other model has that. I think it is a pretty massive GFS error. In fact, the 12z GEM provides no support for either the 15th or 17th (GFS solution) whatsoever. I think the GFS has a pretty signifiant bias right now at over-amping everything at times. However, it can sniff out weather systems like this, because of that bias. For now though, I have the GFS as an outlier and at a level where it almost has to be tossed, but let's see if the Euro has something. What is plausible is a cold front tapping the Gulf, and I won't rule that out with the 17th system. Conversely, the GEM looks suspiciously anemic, and that would be a red flag for that model. A strong cold front w/ short waves in tow...should have some dynamics. The truth is probably somewhere in between the GEM and GFS at 12z.

But holy moly does that turn into a big blizzard along the EC, and that looks a bit more plausible given the spacing. Now, if we can get rid of the Pacific tropical feature, we could manage to get an inland runner???

Healthy looking second system on the GFS, BUT.....it is fooling around w/ that tropical PAC storm-ish feed again, and I think that is likely wrong. It allowed the back of the trough to hang back, and it catches that erroneous(?) feature again. I strongly encourage more support from other modeling before buying that scenario. I hope it scores the coup, but that just doesn't look like reliable synoptics or climatology. I would willing to buy that setup if someone could simply make a case for that being the Pineapple Express(aka atmospheric river hookup).

I mean that is a petty good thump w/ storm #1 w/ 6-12" of snow over TRI - probably a good amount of that is just smoothing due to the mountains. Overall, it looks like roughly 2-4" for many areas in middle and eastern areas of the forum w/ even north Georgia getting some snow.

The 12z GFS, which I like once it is inside of rough 150 hours, is increasing the strength o the clipper ever so slightly. Clippers often trend north at the last minute, and will sometimes get stronger as modeling will sometimes underestimate the strength of the vortex(especially the closer to February that we get).

Larry Cosgrove mentioned last night that the modeling is really struggling with the MJO. He has resorted to simply looking at satellite imagery in the IO, MC, and western Pacific. Why satellite? Says modeling is changing every 12 hours with it.

This forum area has always had wild weather swings. The blizzard of 93 was preceded by one of the worst severe weather events of my lifetime. The 85 cold outbreak was preceded by strong December warmth…dig back through for the analog I posted a while back for that. Why the extremes? Our weather is influenced by five bodies of water…Pacific, Atlantic, Gulf, Arctic, and the the GLs. I mean really the IO does as well so make it six bodies of water. But our proximity to the Gulf allows wild swings between continental derived cold and warmth from a large, shallow body of ocean water. It is why severe weather here is some of the worst on the planet in regards to tornadoes. It is why we have TVA to control what used to be catastrophic flooding which was often preceded by drought. I think we have a fun second half of winter coming up. Take what we get and enjoy it.

Plenty of sustained cold. Many will be below normal for next week. We live in the subtropics….it wants to snow here for about 4 weeks a year. Always important to remember. Plenty still to track. And it’s almost always thread the needle at this latitude. When we get crazy cold, it usually goes dry. We want to be right on the gradient for a chance at big snows.

The GFS has a likely flaw with the 17th system. That error is causing the big runs with the slider. It is trying to hook a Pacific tropical system into the front from 1000+ miles away. There is a faint signature of that on the GEM and nothing on the Euro. That front could work, but it would have to be a Gulf feed or Pineapple Express setup. I don’t see the GFS PAC tropical feature (anomalous for this time of year anyway) on other modeling. The GFS has really struggled this winter….almost unusable at times.

The entire run at 12z was 1-3 feet over most of the state. That is just the second storm.

And I have posted this for a few days. When you see 500 Geopotential maps that look like this, that is the setup for a good winter storm in the Upper South. Moisture feed from the southwest as very cold air crashes in. I remember a storm in 1985 which did something similar. How do I know this? My dad was hauling oil from St Louis that winter. He called and said that he had been barely driving in front of a winter storm the entire trip back to TRI. Sure enough, he pulled in and snow moved in immediately. We had 2-3 foot drifts of cold driven snow in my yard by the next day...I didn't live in the bubble at the time. I have to think this is a similar setup.

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.