Absolute Vorticity

tpweather wrote: ↑Wed Jan 04, 2023 3:19 pm Very interesting on the models later next week. Still believe somewhere in the middle of the month we see a big storm in the east that is a forerunner to a colder pattern. The Euro has a system later next week and with a low to the south of us but a rather strong high northeast of us. I know I have been touting eastern Canada and how that part of the world and how its getting colder can have an impact on us towards mid-month. This happens more in February but can happen anytime in the winter season. These highs get really strong and they expand towards the south and west. When this happens then you see a system to the south that throws moisture northward and you get these wonderful overriding events which depending how deep you are in the cold air will make a difference on precip type including sleet and fr/rain. Very early on this storm system and no prediction this far in advance but the pattern fits a system like this to develop. Once we get into spring that part of Canada is last to warm up and you will see snows in New England in May and even June because of the cold that remains in eastern Canada. So will keep an eye on late next week and way too early to make a storm threat but I could see one by early next week for a late week storm.

Bgoney wrote: ↑Wed Jan 04, 2023 3:49 pm Next 10 days or so of qpf for SoCal. (EPS) That's some 6-9" around LA. They should be able to flush their toilets again..


ecmwf-ensemble-avg-swus-total_precip_inch-3827200.png

tpweather wrote: ↑Wed Jan 04, 2023 3:54 pm Bgoney I did notice the lag times with the mjo. I agree that over the last couple of months it seems to me the lag time is much greater than previous years. I may be off the mark here but it seems that is the case. California getting rain but I thought it never rains in Southern California.

tron777 wrote: ↑Wed Jan 04, 2023 4:23 pm

tpweather wrote: ↑Wed Jan 04, 2023 3:54 pm Bgoney I did notice the lag times with the mjo. I agree that over the last couple of months it seems to me the lag time is much greater than previous years. I may be off the mark here but it seems that is the case. California getting rain but I thought it never rains in Southern California.

Usually in an El Nino and not a La Nina. As I said to Bgoney the other day, welcome to La Nino!

tpweather wrote: ↑Wed Jan 04, 2023 4:29 pm

tron777 wrote: ↑Wed Jan 04, 2023 4:23 pm

tpweather wrote: ↑Wed Jan 04, 2023 3:54 pm Bgoney I did notice the lag times with the mjo. I agree that over the last couple of months it seems to me the lag time is much greater than previous years. I may be off the mark here but it seems that is the case. California getting rain but I thought it never rains in Southern California.

Usually in an El Nino and not a La Nina. As I said to Bgoney the other day, welcome to La Nino!

Tongue in cheek Les on the music verse it never rains in Southern California. I forgot who sang the song but it was a myth that the weather was always sunny in Southern California. Over the years folks moved to where they could grow crops and make a living that way but once in got into the 20th century we could move to places like Southern California or Las Vegas where rainfall was so much less and not easy growing crops. People had the dream of almost perfect weather and of course Hollywood. Guess what to some extent that has become a nightmare as we have years and years where the rain does not fall and years where we get to much in a short period of time. That along with the ever declining Hollywood and of course the political downfall has made it a very unattractive place imo.

tron777 wrote: ↑Wed Jan 04, 2023 4:31 pm

tpweather wrote: ↑Wed Jan 04, 2023 4:29 pm

tron777 wrote: ↑Wed Jan 04, 2023 4:23 pm

tpweather wrote: ↑Wed Jan 04, 2023 3:54 pm Bgoney I did notice the lag times with the mjo. I agree that over the last couple of months it seems to me the lag time is much greater than previous years. I may be off the mark here but it seems that is the case. California getting rain but I thought it never rains in Southern California.

Usually in an El Nino and not a La Nina. As I said to Bgoney the other day, welcome to La Nino!

Tongue in cheek Les on the music verse it never rains in Southern California. I forgot who sang the song but it was a myth that the weather was always sunny in Southern California. Over the years folks moved to where they could grow crops and make a living that way but once in got into the 20th century we could move to places like Southern California or Las Vegas where rainfall was so much less and not easy growing crops. People had the dream of almost perfect weather and of course Hollywood. Guess what to some extent that has become a nightmare as we have years and years where the rain does not fall and years where we get to much in a short period of time. That along with the ever declining Hollywood and of course the political downfall has made it a very unattractive place imo.

Oh I know what you meant Tim. Kind of like that other tune from the Mamas and Papas, "California Dreamin'" Of course in the 1960s sure California was a beautiful place to be and it was hip! In the 2020s we need a more modern version called "California Nightmare!"

tpweather wrote: ↑Wed Jan 04, 2023 4:33 pm Les I believe you are on too something. Great Title for a song and bet it would sell like crazy. BTW California Dreamin would be in my top 20 of all songs.

tpweather wrote: ↑Wed Jan 04, 2023 7:31 pm To me Bgoney it looks like one that is going from phase 6 to 7.

tron777 wrote: ↑Wed Jan 04, 2023 7:33 pm

tpweather wrote: ↑Wed Jan 04, 2023 7:31 pm To me Bgoney it looks like one that is going from phase 6 to 7.

I wonder if the Aussie's calculations then are a day or two off? This is something we would need to study over a period of time to make an accurate calculation.

tron777 wrote: ↑Wed Jan 04, 2023 7:33 pm

tpweather wrote: ↑Wed Jan 04, 2023 7:31 pm To me Bgoney it looks like one that is going from phase 6 to 7.

I wonder if the Aussie's calculations then are a day or two off? This is something we would need to study over a period of time to make an accurate calculation.

Bgoney wrote: ↑Wed Jan 04, 2023 7:41 pm

tron777 wrote: ↑Wed Jan 04, 2023 7:33 pm

tpweather wrote: ↑Wed Jan 04, 2023 7:31 pm To me Bgoney it looks like one that is going from phase 6 to 7.

I wonder if the Aussie's calculations then are a day or two off? This is something we would need to study over a period of time to make an accurate calculation.

I thought a lot 6 into 7 also. Just to note for all , that phase map is precip anomalies for a particular phase

tron777 wrote: ↑Thu Jan 05, 2023 8:31 am Good morning all! Not a lot of change to report in the overnight guidance. Don't expect a favorable pattern for snow lovers until we get to mid month and beyond. The next 10 days or so will continue to be seasonal to slightly above with possible chances for snow, but timing is everything with this pattern and you're really going to have to thread the needle to have a chance.

We are still watching the MJO to see how it will behave by then. If things break correctly, we'll have a much better last 10 days of January and perhaps early Feb as well. So that's where we're at with the longer term pattern. We are basically in watch and wait mode there at this time.

Bgoney wrote: ↑Thu Jan 05, 2023 8:44 am

tron777 wrote: ↑Thu Jan 05, 2023 8:31 am Good morning all! Not a lot of change to report in the overnight guidance. Don't expect a favorable pattern for snow lovers until we get to mid month and beyond. The next 10 days or so will continue to be seasonal to slightly above with possible chances for snow, but timing is everything with this pattern and you're really going to have to thread the needle to have a chance.

We are still watching the MJO to see how it will behave by then. If things break correctly, we'll have a much better last 10 days of January and perhaps early Feb as well. So that's where we're at with the longer term pattern. We are basically in watch and wait mode there at this time.

Yep, the first half is playing out like we thought , from a while back. Only thing I would add now since we're nearing the end of week one , is that I'm leaning on week 3 also having the Arctic closed for much of the lower 48. We talked about how the ALEUTIAN LOW pattern can be hard to break and it looks to hold on a bit longer still , the coldest air in the Nhemisphere will slowly work its way through Russia during the next 1-2 weeks into NW Canada. Then we need a mechanism set-up to transport it all the way down into Canada then the 48

tron777 wrote: ↑Thu Jan 05, 2023 8:55 am

Bgoney wrote: ↑Thu Jan 05, 2023 8:44 am

tron777 wrote: ↑Thu Jan 05, 2023 8:31 am Good morning all! Not a lot of change to report in the overnight guidance. Don't expect a favorable pattern for snow lovers until we get to mid month and beyond. The next 10 days or so will continue to be seasonal to slightly above with possible chances for snow, but timing is everything with this pattern and you're really going to have to thread the needle to have a chance.

We are still watching the MJO to see how it will behave by then. If things break correctly, we'll have a much better last 10 days of January and perhaps early Feb as well. So that's where we're at with the longer term pattern. We are basically in watch and wait mode there at this time.

Yep, the first half is playing out like we thought , from a while back. Only thing I would add now since we're nearing the end of week one , is that I'm leaning on week 3 also having the Arctic closed for much of the lower 48. We talked about how the ALEUTIAN LOW pattern can be hard to break and it looks to hold on a bit longer still , the coldest air in the Nhemisphere will slowly work its way through Russia during the next 1-2 weeks into NW Canada. Then we need a mechanism set-up to transport it all the Only talking airmass here and not individual chances for wintery precip that may pop up down into Canada then the 48.

I keep hearing talk on the "Weather Net" that a possible mechanism could be the PV elongating and getting stretched out again, like what we saw back in December. That allowed that nice blocking pattern to develop. However, I do remain skeptical of that happening since the PV is much stronger now then it was back in early December. We'll just have to wait and see. If you go by trends... since we have entered this Triple Dip Nina, January has been a warm month with winter making a nice come back in February. Will that be the case this year too? Time will tell.

Bgoney wrote: ↑Thu Jan 05, 2023 8:44 am

tron777 wrote: ↑Thu Jan 05, 2023 8:31 am Good morning all! Not a lot of change to report in the overnight guidance. Don't expect a favorable pattern for snow lovers until we get to mid month and beyond. The next 10 days or so will continue to be seasonal to slightly above with possible chances for snow, but timing is everything with this pattern and you're really going to have to thread the needle to have a chance.

We are still watching the MJO to see how it will behave by then. If things break correctly, we'll have a much better last 10 days of January and perhaps early Feb as well. So that's where we're at with the longer term pattern. We are basically in watch and wait mode there at this time.

Yep, the first half is playing out like we thought , from a while back. Only thing I would add now since we're nearing the end of week one , is that I'm leaning on week 3 also having the Arctic closed for much of the lower 48. We talked about how the ALEUTIAN LOW pattern can be hard to break and it looks to hold on a bit longer still , the coldest air in the Nhemisphere will slowly work its way through Russia during the next 1-2 weeks into NW Canada. Then we need a mechanism set-up to transport it all the way down into Canada then the 48. Only talking airmass here and not individual chances for wintery precip that may pop up

tpweather wrote: ↑Thu Jan 05, 2023 9:38 am

Bgoney wrote: ↑Thu Jan 05, 2023 8:44 am

tron777 wrote: ↑Thu Jan 05, 2023 8:31 am Good morning all! Not a lot of change to report in the overnight guidance. Don't expect a favorable pattern for snow lovers until we get to mid month and beyond. The next 10 days or so will continue to be seasonal to slightly above with possible chances for snow, but timing is everything with this pattern and you're really going to have to thread the needle to have a chance.

We are still watching the MJO to see how it will behave by then. If things break correctly, we'll have a much better last 10 days of January and perhaps early Feb as well. So that's where we're at with the longer term pattern. We are basically in watch and wait mode there at this time.

Yep, the first half is playing out like we thought , from a while back. Only thing I would add now since we're nearing the end of week one , is that I'm leaning on week 3 also having the Arctic closed for much of the lower 48. We talked about how the ALEUTIAN LOW pattern can be hard to break and it looks to hold on a bit longer still , the coldest air in the Nhemisphere will slowly work its way through Russia during the next 1-2 weeks into NW Canada. Then we need a mechanism set-up to transport it all the way down into Canada then the 48. Only talking airmass here and not individual chances for wintery precip that may pop up

Good Morning and Bgoney you made a key point and something I have been hammering on for days if not weeks. The cold in Siberia and where does it go is always a key in us getting polar air down here. The coldest of air returned to Siberia about the New Year. Stayed in eastern Siberia the first 3 days but what I noticed from the overnight reports is the cold is heading more towards western Siberia and the Baltic area. Almost always when this happens it will take a few weeks before we see a polar outbreak across the central and eastern USA. So what does this mean in terms of winter weather. No doubt we can still get some winter weather and one reason is the cold in eastern Canada and how the high is building over the next week or so. This type of setup is one where the cold expands south and west but can only go so far plus very little snow on the ground and the central plains are getting rather mild over the next week. That temp difference is one of the items we look at for an overriding event. So do we see a storm later next week and most likely yes but the location is not known this far in advance. Back in December the models were way to fast in bringing the cold and on here we stayed the course and kept it coming after mid-month. This month I thought I had it returning mid-month to a more seasonal cold which is already starting to happen but I thought a true polar air mass would come the following week but with the cold on the move in Siberia is correct then we will have another milder spell after next week and then we look towards the last week of January and early February for a polar outbreak. The mjo seems to have us going into phase 8 and 1 later this month and again if that is correct then yes the chances go up for some better chances of winter weather. Most winters around here are broken up where you have 4 weeks of no chance to get winter weather,4 weeks the chances are about 50/50 and then 4 weeks where the pattern is wonderful for winter weather. Of course this is not set in stone every year but I do use that for Dec 1st -Feb 28th.

Bgoney wrote: ↑Thu Jan 05, 2023 10:16 am

tpweather wrote: ↑Thu Jan 05, 2023 9:38 am Good Morning and Bgoney you made a key point and something I have been hammering on for days if not weeks. The cold in Siberia and where does it go is always a key in us getting polar air down here. The coldest of air returned to Siberia about the New Year. Stayed in eastern Siberia the first 3 days but what I noticed from the overnight reports is the cold is heading more towards western Siberia and the Baltic area. Almost always when this happens it will take a few weeks before we see a polar outbreak across the central and eastern USA. So what does this mean in terms of winter weather. No doubt we can still get some winter weather and one reason is the cold in eastern Canada and how the high is building over the next week or so. This type of setup is one where the cold expands south and west but can only go so far plus very little snow on the ground and the central plains are getting rather mild over the next week. That temp difference is one of the items we look at for an overriding event. So do we see a storm later next week and most likely yes but the location is not known this far in advance. Back in December the models were way to fast in bringing the cold and on here we stayed the course and kept it coming after mid-month. This month I thought I had it returning mid-month to a more seasonal cold which is already starting to happen but I thought a true polar air mass would come the following week but with the cold on the move in Siberia is correct then we will have another milder spell after next week and then we look towards the last week of January and early February for a polar outbreak. The mjo seems to have us going into phase 8 and 1 later this month and again if that is correct then yes the chances go up for some better chances of winter weather. Most winters around here are broken up where you have 4 weeks of no chance to get winter weather,4 weeks the chances are about 50/50 and then 4 weeks where the pattern is wonderful for winter weather. Of course this is not set in stone every year but I do use that for Dec 1st -Feb 28th.

In total agreement with the pattern the next 2 weeks +. I do like the trends of the EPS for late next week. That look with the Canadian high over top in that position I always thought it as "backdoor" cold and add add a shortwave development , we have a chance anyways