Absolute Vorticity

tron777 wrote: ↑Sat Dec 02, 2023 12:47 pm 12Z GFS today is offering up an interesting scenario and honestly, it is not far fetched either. Meteorologically, it makes sense and could happen. The Dec 10th system is a deepening low that moves thru the OV and it delivers in a nice batch of cold air. Then we get a follow up wave in the STJ that brings up moisture from the Gulf for a light snow chance on the 13th. Timing is everything. You need a strong low to drag down the cold air, then get a follow up wave to pass thru while the cold air is in place before we warm up again.

Hey Les I agree. Of course we have other factors and one being the cold air mass. Very little in the northern and central plains over the next 10 days or so. Look to be near or in phase 7 of the mjo which is colder in the northern plains and heading towards colder weather here. Can we grab some of the cold from Alaska and northwest Canada which does look to get cold next week. So yes the models have seen this before and is throwing out a possible situation but we really need things to go perfect to get in on some snow.

tpweather wrote: ↑Sat Dec 02, 2023 1:05 pm

tron777 wrote: ↑Sat Dec 02, 2023 12:47 pm 12Z GFS today is offering up an interesting scenario and honestly, it is not far fetched either. Meteorologically, it makes sense and could happen. The Dec 10th system is a deepening low that moves thru the OV and it delivers in a nice batch of cold air. Then we get a follow up wave in the STJ that brings up moisture from the Gulf for a light snow chance on the 13th. Timing is everything. You need a strong low to drag down the cold air, then get a follow up wave to pass thru while the cold air is in place before we warm up again.

Hey Les I agree. Of course we have other factors and one being the cold air mass. Very little in the northern and central plains over the next 10 days or so. Look to be near or in phase 7 of the mjo which is colder in the northern plains and heading towards colder weather here. Can we grab some of the cold from Alaska and northwest Canada which does look to get cold next week. So yes the models have seen this before and is throwing out a possible situation but we really need things to go perfect to get in on some snow.

No doubt Tim! It is a possible solution but not a slam dunk by any means. You have to have many things to go right. Cause and effect.

Les all 3 main models have something in that time period so that is a nice sign this far out.

tpweather wrote: ↑Sat Dec 02, 2023 1:56 pm Les all 3 main models have something in that time period so that is a nice sign this far out.

I agree Tim. Lots can change but we've got to start somewhere. I like the trends so far today of the Dec 10th storm being a stronger low and that is the first critical piece that we need to see snow in this warmer pattern that we're in. Once we can get that nailed down then the second piece is the timing of the next wave in the STJ.

Good evening folks! Just finished putting the tree up. A 7 1/2 footer with 1200 LED lights, garland, and around 600 ornaments!


Back to the weather, and CVG topped out at 54 today, 56 here. Another mild night in store with another mild day tomorrow also with a chance for light rain showers. Not a big deal really at all. Same deal for Monday. Temps then drop back to normal levels with highs in the 40s Tues and Wed with the 50s returning towards the end of the week. We are roughly about 8 days or so away from our next significant storm system.

The 18Z GFS is not called the Happy Hour GFS for nothing. Several chances for wintry weather now showing up in the extended range. I suppose it matches the above pic of my tree fairly well. Just goes to show you what can happen when the EPO goes negative and a massive Alaskan Block to boot.

Love the tree Les.

tpweather wrote: ↑Sat Dec 02, 2023 6:46 pm Love the tree Les.

Thank you Tim!

Beautiful tree!!!

I find it interesting that we get this pretty healthy trough digging into the central and eastern part of the country behind next week's storm considering the MJO will have been traveling through the warm phases over the next week. If this were to verify it would go to show the MJO phase doesn't always correlate to the average look across the country for that particular phase. (images compliments of CB)

CVG reached 54, DAY 52 and CMH 56 today.

Beautiful tree, Les!

Love the tree Les, but is that a smallmouth mounted on your wall?

00z GFS continues to show a colder solution for the cutter. Rain to snow and falling temps.

dce wrote: ↑Sat Dec 02, 2023 8:18 pm I find it interesting that we get this pretty healthy trough digging into the central and eastern part of the country behind next week's storm considering the MJO will have been traveling through the warm phases over the next week. If this were to verify it would go to show the MJO phase doesn't always correlate to the average look across the country for that particular phase. (images compliments of CB)

Combo of -AO/-NAO tampering MJO normal effects

Good Morning and we look to get somewhat busier this week. Doug you make a great point about the MJO in the warmer phases. When you have a -AO and a negative to neutral NAO you can still get some cold air to work into these systems especially the further northeast you are located. The mjo is in phase 4 or 5 by next weekend but its rather weak as well so that helps. Having the snow in eastern Canada over the past few weeks as well helps in getting whatever cold is available able to work southward somewhat easier.

Tellies are nice to follow but sometimes a puzzle to which one is trying to control the weather.

We have a few little systems early this week that can produce some rain and maybe a bit of snow but nothing that will cause problems locally but if you head northeast you may see minor accumulations though the ground is rather warm. Then we warm up late in the week and next weekend. Models are showing a decent storm that forms in the central part of the USA. This would be a rain to snow situation for us and normally that is not the best way for us to get snow accumulations. If the storm can slow down a tad there is a chance to bring more of the cold over eastern Canada into the system to see a period of snow but just way too early at this point.

Then we should return to the above normal temps until at least the 20th or so of the month. The last ten days of December look interesting and though it may not be the coldest outlook ever getting near to slightly below normal in temps can help. The STJ looks to be busy as well but like I have mentioned this winter is the east coast looks to be the winner in terms of cold and snow this winter and we will get some of the leftovers plus I believe once the El Nino starts getting weaker we will see a couple of bigger storms in our area as well.

Funny that the gfs has not been in a hurry like some winters to turn things colder and that is good plus correct imo. Will there be a SSW event and models still trying to show that but as we know even if one occurs it usually takes a couple of weeks before we would see anything and that would put us in January.

Just the other day I mentioned that the coldest I could find in Siberia was -17. That has done a 180 and the lowest I see is -59. What I have noticed this fall is a couple of things in Siberia. First they have been rather mild and had a late start to snowfall. Second which may be more important is when they get cold it does not hang around for a long period of time. Does this mean if we get a SSW that it can disturb the PV easier than normal and not sure but what I have seen so far this season is the PV has been stretched out several times and you get those spokes of cold air like we have seen 2 times locally and also eastern Europe.

Modiels performing with their usual progression(10th) at this range of multiple scenarios as new data comes in. Moving back and forth in figuring out the positions and strength of Ridges on both sides of the trough and the position and strength of the trough itself, let alone where or when the Low will close off. As mentioned by many , alot needs to go perfect for accumulations in a warm pre-existing airmass. Give me the current Oz EU perfect scenario for the Wednesday night model run and i"ll be happy

The forecast for the MJO progression eastward and amplitude is even more suspect than usual imo. We have currently a tropical cyclone in the Bay of Bengal (who-Dey) or in 2/3 phases. From years past we know sometimes tropical systems can wreak havoc on MJO forecasts

Great Post Bgoney. I will give you my best answer and that is I have no idea what this will do to the mjo. The mjo is weak and will that help it moving through the phases. That is why looking around the globe though is so important and we tend to take info from mainly North America but the global aspects are such an important part of everyone's weather.

Bgoney wrote: ↑Sun Dec 03, 2023 8:59 am The forecast for the MJO progression eastward and amplitude is even more suspect than usual imo. We have currently a tropical cyclone in the Bay of Bengal (who-Dey) or in 2/3 phases. From years past we know sometimes tropical systems can wreak havoc on MJO forecasts




IMG_0935.jpeg

Good post! Tropical cyclones in that region can absolutely throw a wrench into MJO forecasts.

Bgoney wrote: ↑Sun Dec 03, 2023 7:35 am Modiels performing with their usual progression(10th) at this range of multiple scenarios as new data comes in. Moving back and forth in figuring out the positions and strength of Ridges on both sides of the trough and the position and strength of the trough itself, let alone where or when the Low will close off. As mentioned by many , alot needs to go perfect for accumulations in a warm pre-existing airmass. Give me the current Oz EU perfect scenario for the Wednesday night model run and i"ll be happy

Yes we are absolutely in the range of expected variances and inconsistencies in model runs.

Good morning all! I want to start off by saying thank you for the compliments on the Christmas Tree and yes that is a small mouth bass that weighed in at 6 1/2 pounds. We have several big 11-12 pound walleye a 2 1/2 pound crappie and another smallie that came in at over 7 pounds that are also mounted on various walls!

Back to the weather and you guys have some wonderful posts going on and these are outstanding discussions that we are having on here! The cutter idea Trev and I have talked about for the Dec 10th system makes sense. But at the same time, the little details matter. The position of the -AO and -NAO blocks matter. It is not always about how negative or positive a certain Teleconnection is in. The shape or orientation of a ridge or trough axis really does matter in terms of our sensible weather. Don't concentrate so much on a number or a value, but focus on the smaller details and you will then understand why a model is showing a certain solution that it is showing.

Same with the MJO Phase. Don't focus so much as to what phase it is in. The amplitude of the phase is what matters most. Remember, when you are looking at the MJO Wheeler Plot, the closer the MJO wave is to the neutral circle, the weaker it is. Thus, the less influence it will have on the overall pattern. The further away it is from the neutral circle, the stronger or more amplified the wave is and thus, the MJO will have more of an influence on the overall pattern.

A lot of this post our wonderful and talented AV Forecasters already know. But it's a good time to review everything. This is a good learning experience for us all to be honest. Bgoney also brought up a great point about tropical cyclones. They absolutely have an impact on the MJO wave itself in terms of amplitude and what phase it will be in. The modeling won't handle it correctly either. It's a feedback process. Cause and effect. The MJO also can destructively interfere with the ENSO state. In this case El Nino. We have said time and time again that this El Nino is not acting like a strong or super El Nino despite the SST's and numbers that came out each week in each of the ENSO regions (1+2, 3, 3.4 and 4) How did we know that? By looking at the overall bigger picture. This is why the smaller details matter.

Concerning the Dec 10th system, which of course is our next system of interest, I think the Cutter solution is absolutely still on the table, just as much as a rain to accumulating snow solution with wind and falling temps. It is too early to truly know, so we have several more days of watching the guidance to see what trends we can pick up on. We will be doing just that so stay tuned my friends! The fun is just getting ready to begin on AV. Don't forget to tell your friends and family, co-workers etc about our forum and the wonderful weather family that we have here. Drop me a PM via the forum or on Facebook. You can also shoot me an email if you ever have any problems and / or questions. Thank you!

Hi Les,

That big clock you have is similar to one that my folks and I have.

Currently 46 here in G'ville and progged to top out at around 48 today.

We can add another solution to the list of GFS solutions: no phase and we are left with an open wave to at most a very weak closed low.

The 12Z Canadian went that route also, but the GEFS still looks more like what we saw last night, a more phased / well developed system.

12Z UKIE is slower, more phased, and offers up the cutter solution.