Absolute Vorticity

CFSV2 Temp forecast for December the last few runs... definitely looking active for us as you can see by the temp departure layout.

12Z Euro has similar timing and amounts as the GFS with the first front for Sat. The Euro isn't quite as wet Monday and Tuesday of next week like the GFS was, but the Euro has a similar look with that slow moving frontal boundary that we talked about as the -NAO gets established. This is why we are getting the SE Ridge. It's very normal to see in winter when blocking gets going in the arctic areas. It is after the first 10 days, that I continue to watch for changes.

HI everyone- popping in. I'm here when there is severe weather or snow. Hoping for more snow and less cold rain this year!

BookNerdCarp wrote: ↑Mon Nov 28, 2022 8:46 pm What’s everyone’s general opinion on YouTuber Ryan Hall?

I like him, and watched him a lot during the Spring into summer (actually have him on right now covering the storms in the south). I echo the thoughts of how he raises money to help those impacted by storms and that the storm chasers will stop to help instead of just getting videos to get likes. The team has people covering the storms out in the field, radar, police scanners, and social media- its a pretty cool set up and they are all genuine and take themselves (definitely the topic at hand) seriously enough but not too much. They also try to teach the viewers about what to look for on the radar and why they are concerned about what they are seeing.

MJSun wrote: ↑Tue Nov 29, 2022 4:08 pm HI everyone- popping in. I'm here when there is severe weather or snow. Hoping for more snow and less cold rain this year!

BookNerdCarp wrote: ↑Mon Nov 28, 2022 8:46 pm What’s everyone’s general opinion on YouTuber Ryan Hall?

I like him, and watched him a lot during the Spring into summer (actually have him on right now covering the storms in the south). I echo the thoughts of how he raises money to help those impacted by storms and that the storm chasers will stop to help instead of just getting videos to get likes. The team has people covering the storms out in the field, radar, police scanners, and social media- its a pretty cool set up and they are all genuine and take themselves (definitely the topic at hand) seriously enough but not too much. They also try to teach the viewers about what to look for on the radar and why they are concerned about what they are seeing.

This is awesome! You are the second person to say that today. Good stuff and like I said earlier, this is very refreshing and great to see someone using social media the way it should be used. Glad to see you back and stay tuned since we're watching some big time blocking setting up soon!

12Z EPS was one of the best runs I have seen yet! -EPO / -NAO develops as we already know but also towards the end of the run, a +PNA also develops! That would be interesting for cold weather that is for sure. Always a crap shoot with snow of course but you do need cold to get snow.

tron777 wrote: ↑Tue Nov 29, 2022 6:26 pm 12Z EPS was one of the best runs I have seen yet! -EPO / -NAO develops as we already know but also towards the end of the run, a +PNA also develops! That would be interesting for cold weather that is for sure. Always a crap shoot with snow of course but you do need cold to get snow.

Les the positive PNA is key in a pattern like this imo. That has been a trend and it was creeping towards neutral so if it goes somewhat positive but not overwhelming the we are looking at a nice second half of December

Good Morning and some good news about the cold heading this way. The coldest of air has been bottled up over the northern part of Canada. Finally we are seeing movement and this is one of the first signs the cold is getting ready to advance towards us over the next few weeks. Models can detect these colder outbreaks but seem to rush them here especially early in the winter season. The cold has advanced into central Canada and soon will going into southern Canada. Then we just wait for several systems to pass with each one grabbing some cold air and the will slowly worked its way into the USA. This is the only forum I get on but my guess some folks in other forums are worried about how the cold has not made much headway so far. Patience is the word and if you want the cold and maybe snow it just takes time and not even into December yet so everything is good.

Morning Tim! The MJO has made it into Weak Phase 8 now per the Aussies. However, the wave is weakening now and it might be headed towards the neutral circle. We'll see an eye on it.

For now... before we get there yes or no on heavy rains Monday and Tues of next week? We get the warning shot of rain Sat as a front moves in. Then, does the next front stall out for heavy rains Sunday night - Tuesday or does the front blast thru with minimal rains? Lately, we have seen the heavier rain scenario showing up until last night. GFS and Euro from overnight have the heavier rains south of us at this time. We shall see!

tron777 wrote: ↑Wed Nov 30, 2022 7:56 am Morning Tim! The MJO has made it into Weak Phase 8 now per the Aussies. However, the wave is weakening now and it might be headed towards the neutral circle. We'll see an eye on it.

For now... before we get there yes or no on heavy rains Monday and Tues of next week? We get the warning shot of rain Sat as a front moves in. Then, does the next front stall out for heavy rains Sunday night - Tuesday or does the front blast thru with minimal rains? Lately, we have seen the heavier rain scenario showing up until last night. GFS and Euro from overnight have the heavier rains south of us at this time. We shall see!

Good Morning Les and I saw that with the overnight runs. The mjo and again if it remains in the COD for a period of time then expect the same pattern to continue over the next 10 days or so. The heavier rains for next week and the CMC has been on the colder side next week so the GFS and Euro moved towards that model last night. We will see and watch the trends over the next few days. Yes a nice cold shot mid/late next week and is that the start of the change or just a short shot of some decent cold air. To early to say its the pattern change but we are starting to get colder late next week.

tpweather wrote: ↑Wed Nov 30, 2022 8:12 am

tron777 wrote: ↑Wed Nov 30, 2022 7:56 am Morning Tim! The MJO has made it into Weak Phase 8 now per the Aussies. However, the wave is weakening now and it might be headed towards the neutral circle. We'll see an eye on it.

For now... before we get there yes or no on heavy rains Monday and Tues of next week? We get the warning shot of rain Sat as a front moves in. Then, does the next front stall out for heavy rains Sunday night - Tuesday or does the front blast thru with minimal rains? Lately, we have seen the heavier rain scenario showing up until last night. GFS and Euro from overnight have the heavier rains south of us at this time. We shall see!

Good Morning Les and I saw that with the overnight runs. The mjo and again if it remains in the COD for a period of time then expect the same pattern to continue over the next 10 days or so. The heavier rains for next week and the CMC has been on the colder side next week so the GFS and Euro moved towards that model last night. We will see and watch the trends over the next few days. Yes a nice cold shot mid/late next week and is that the start of the change or just a short shot of some decent cold air. To early to say its the pattern change but we are starting to get colder late next week.

The GFS just seems awfully progressive and fast on its overnight run where the CMC and Euro weren't as bad. However, they both keep the heavier rains south of us. I don't have a problem with the location or placement of the heavier rain axis, esp being 4 or 5 days out. I do have a problem with the any guidance that blasts a system through here. With that -NAO building in, I am under the assumption that the slower moving frontal idea should be correct. Where the front stalls of course remains to be seen. With the cold pressing in from the NW and the ridge flexing itself from the SE, us being right in the middle makes sense so the earlier runs we saw showing an inch or two of rain to me looks good. We've got plenty of time to see how this works out.

Les the way I look at it is since I see signs of the colder starting to move and once it gets in gear then we need to watch out. Did the models pick up on something last night and if so to me that means they are starting to see some colder air making some head ways. Not saying this is the main push next week but could be a rather nice warning shot and yes you can get snow out that pattern. At this time sort of going to leave the mjo on the side burner and not because its not important but other things may be dictating the weather and the is the AO and NAO starting next week.

tpweather wrote: ↑Wed Nov 30, 2022 8:27 am Les the way I look at it is since I see signs of the colder starting to move and once it gets in gear then we need to watch out. Did the models pick up on something last night and if so to me that means they are starting to see some colder air making some head ways. Not saying this is the main push next week but could be a rather nice warning shot and yes you can get snow out that pattern. At this time sort of going to leave the mjo on the side burner and not because its not important but other things may be dictating the weather and the is the AO and NAO starting next week.

I don't think the main push of cold air comes until Week 3 of Dec as we approach mid month. That is when wintry weather potential should go way up for us as well as the Mid Atl / East Coast areas.

tron777 wrote: ↑Wed Nov 30, 2022 8:48 am

tpweather wrote: ↑Wed Nov 30, 2022 8:27 am Les the way I look at it is since I see signs of the colder starting to move and once it gets in gear then we need to watch out. Did the models pick up on something last night and if so to me that means they are starting to see some colder air making some head ways. Not saying this is the main push next week but could be a rather nice warning shot and yes you can get snow out that pattern. At this time sort of going to leave the mjo on the side burner and not because its not important but other things may be dictating the weather and the is the AO and NAO starting next week.

I don't think the main push of cold air comes until Week 3 of Dec as we approach mid month. That is when wintry weather potential should go way up for us as well as the Mid Atl / East Coast areas.

I agree Les and that has been my timetable all along but you can get warning shots and we have one today and Thursday plus I expect another late next week. We want to see more snow cover to the north and west and though Minneapolis area got hit nicely yesterday it was a rather narrow band that went through. Hoping to see more snow in the central plains and upper mid-west in the coming week or so.

Some more long range thoughts of mine...

The -NAO is now within 5 days and it's no longer considered fantasy. Actually, confidence should be sky high at this point. This only makes the pattern have marginal cold. This is not going to be a very cold pattern to start out with. Thus, the rain chances during the 1st week of December that we are watching. Now... if we skip ahead to my call of 12/10-12/15 time frame of real deal winter kicking in, yes sir! I am still seeing great signals for this idea occurring on the Ensemble guidance.

As the -NAO begins to retrograde west and decay a bit towards the Davis Straight, ridging is forecast to develop in the EPO and maybe even the PNA domains. If correct... if this pans out... Then we've got blocking over the top and ridging along the West coast of North America. I mean googly moogly! Things are going to get fun in my opinion should the Teleconnections align themselves as such. The second half of Dec and going into January holds a lot of potential in my mind right now. We may actually have wintry weather during the Holiday Season when you'd expect it instead of a record setting -PNA and 70s.

tron777 wrote: ↑Wed Nov 30, 2022 9:00 am Some more long range thoughts of mine...

The -NAO is now within 5 days and it's no longer considered fantasy. Actually, confidence should be sky high at this point. This only makes the pattern have marginal cold. This is not going to be a very cold pattern to start out with. Thus, the rain chances during the 1st week of December that we are watching. Now... if we skip ahead to my call of 12/10-12/15 time frame of real deal winter kicking in, yes sir! I am still seeing great signals for this idea occurring on the Ensemble guidance.

As the -NAO begins to retrograde west and decay a bit towards the Davis Straight, ridging is forecast to develop in the EPO and maybe even the PNA domains. If correct... if this pans out... Then we've got blocking over the top and ridging along the West coast of North America. I mean googly moogly! Things are going to get fun in my opinion should the Teleconnections align themselves as such. The second half of Dec and going into January holds a lot of potential in my mind right now. We may actually have wintry weather during the Holiday Season when you'd expect it instead of a record setting -PNA and 70s.

I agree Les and maybe a winter of the past where we get a decent cold and snow set up for the holidays into early Jan and then a mid-later Jan thaw which is fine because by then we need cold to build up once again in the polar regions. Then we wait to see the pattern for Feb and if the cold in the polar regions head this way or decides to bypass next time.

tpweather wrote: ↑Wed Nov 30, 2022 9:20 am

tron777 wrote: ↑Wed Nov 30, 2022 9:00 am Some more long range thoughts of mine...

The -NAO is now within 5 days and it's no longer considered fantasy. Actually, confidence should be sky high at this point. This only makes the pattern have marginal cold. This is not going to be a very cold pattern to start out with. Thus, the rain chances during the 1st week of December that we are watching. Now... if we skip ahead to my call of 12/10-12/15 time frame of real deal winter kicking in, yes sir! I am still seeing great signals for this idea occurring on the Ensemble guidance.

As the -NAO begins to retrograde west and decay a bit towards the Davis Straight, ridging is forecast to develop in the EPO and maybe even the PNA domains. If correct... if this pans out... Then we've got blocking over the top and ridging along the West coast of North America. I mean googly moogly! Things are going to get fun in my opinion should the Teleconnections align themselves as such. The second half of Dec and going into January holds a lot of potential in my mind right now. We may actually have wintry weather during the Holiday Season when you'd expect it instead of a record setting -PNA and 70s.

I agree Les and maybe a winter of the past where we get a decent cold and snow set up for the holidays into early Jan and then a mid-later Jan thaw which is fine because by then we need cold to build up once again in the polar regions. Then we wait to see the pattern for Feb and if the cold in the polar regions head this way or decides to bypass next time.

Great post! That is exactly my thought process on this. Examples of winters where the Nina dominated too much and winter did not come back after the thaw: 1989-1990 and 2010-2011 However, here is an example where the Nina weakened and winter did come back sometime in Jan and into Feb. Or you had a good March. etc etc. That was 1995-1996. There are probably more that I am not thinking of right now. So that's where I'm at. We get wintry periods mid Dec thru early Jan. Get the thaw. Then if it's like 95-96, we will see more action. If it's like 89-90 or 2010-11 then winter ends early. I think if the Nina weakens fast enough (thanks to the blocking we've been seeing) a 95-96 outcome is more likely versus getting no blocking, or if the Nina stays too strong for too long.

12Z GFS died at 156 hours. I guess the upgrade killed it.

tron777 wrote: ↑Wed Nov 30, 2022 12:09 pm 12Z GFS died at 156 hours. I guess the upgrade killed it.

I am going with the upcoming negative NAO has stopped the model in its tracks

It's slowly coming in now... The model doesn't give us much rain at all until Tues into Wed of next week. Any decent rains before that are too our south. The pattern is absolutely loaded with storm systems. We'll need to give it more time to see how the blocking impacts the pattern. You know my thoughts and my call already for the longer term. The CMC keeps the heavy rain threat above early next week then some sleet or mix towards the end of the week.

The OP GFS also keeps the PNA negative on this run and the GEFS by Day 10 shows some weak +PNA ridging so of course, it will come in as a colder run then the OP model. So Tim, as you mentioned earlier, the PNA is key. It can still work with a -PNA but timing and luck become more of a factor.

tron777 wrote: ↑Wed Nov 30, 2022 12:29 pm It's slowly coming in now... The model doesn't give us much rain at all until Tues into Wed of next week. Any decent rains before that are too our south. The pattern is absolutely loaded with storm systems. We'll need to give it more time to see how the blocking impacts the pattern. You know my thoughts and my call already for the longer term. The CMC keeps the heavy rain threat above early next week then some sleet or mix towards the end of the week.

We know the CMC was the first to see a colder upcoming week and lets see if the GFS and Euro follow. This model gets the extended correct about 3 or 4 times a winter ahead of the other 2 models but once the other two come around the CMC gets goofy once again. I have no ideal why but have seen in many winter seasons.

tron777 wrote: ↑Wed Nov 30, 2022 12:29 pm It's slowly coming in now... The model doesn't give us much rain at all until Tues into Wed of next week. Any decent rains before that are too our south. The pattern is absolutely loaded with storm systems. We'll need to give it more time to see how the blocking impacts the pattern. You know my thoughts and my call already for the longer term. The CMC keeps the heavy rain threat above early next week then some sleet or mix towards the end of the week.

The pattern is absolutely loaded with storms. That is what really stuck out to me in this post. With the cold air that is about to become available in the Great Lakes and Midwest, someone is going to see accumulating snow. Probably quite a bit.

dce wrote: ↑Wed Nov 30, 2022 12:47 pm

tron777 wrote: ↑Wed Nov 30, 2022 12:29 pm It's slowly coming in now... The model doesn't give us much rain at all until Tues into Wed of next week. Any decent rains before that are too our south. The pattern is absolutely loaded with storm systems. We'll need to give it more time to see how the blocking impacts the pattern. You know my thoughts and my call already for the longer term. The CMC keeps the heavy rain threat above early next week then some sleet or mix towards the end of the week.

The pattern is absolutely loaded with storms. That is what really stuck out to me in this post. With the cold air that is about to become available in the Great Lakes and Midwest, someone is going to see accumulating snow. Probably quite a bit.

No doubt in my mind, Doug! We shall see as the weeks go by who or where that is. We've got just as good of a chance as the Lakes and New England do with the blocking being shown.

12Z Euro has showers Fri night ending Sat morning then a cold and dry weekend. Next system brings rain late Monday into Tues. Rainfall amounts thru this time aren't much, about a half inch for CVG. I've been talking about an inch or more. No need to change anything yet since it's only Wednesday but something to keep in mind.

I believe Les mentioned earlier and that is when the blocking near Greenland moves further west in time. This allows for a more normal position of the southeast ridge south and east of the Bahamas. This just takes time and with a strong high over the Yucatan we need this to happen. So yes next week looks colder especially the northern third of the USA with some temps getting to 20 degrees below normal at times but with the Yucatan high there is a fight and that is why it looks rather stormy. So again most likely next week to 10 days we are in that rain to sometimes light snow on the back end of systems but getting towards the middle of the month hopefully things have moved around enough so systems can dig deeper into the south central states. The cold in Canada is cold but nothing out of the ordinary but the cold is taking over a larger area of real estate and this is key for the cold remaining cold over the next several weeks. Getting those narrow shots of cold air is just that narrow and its in and out quickly. Cold taking up more real estate and the cold just slowly works its way southward and usually between mid-Dec and mid-Feb the cold tends to win those battles more often than not.