Absolute Vorticity

tron777 wrote: ↑Sat Dec 10, 2022 12:35 pm 12Z Canadian continues with the most consistent look of a strong Nor' Easter and we get wrap around snow showers Fri ending on Sat. Our first possible event would be around the 20th or so which I've said a few times already. 12Z GEFS looks good with the Nor 'Easter as well. Then by the 18-19th there is energy over the SW that ejects out for our possible around the 20th system. A decent signal from the GEFS today on that.

I agree Les and that is a wonderful pattern for us locally. Southern energy heading east and hopefully northeast over time. Giving the CMC a solid A so far on the pattern recognition. Euro probably a B since its had a few mishaps along the way and the GFS I will give a solid D and that is because I am nice.

This first storm is wild and shows you when we have blocking you get some blockbuster storms.l May not be the strongest of all time but you may get 48 hours of snowfall and got a feeling the totals are going to be over 2 feet in parts of South Dakota and northwestern Nebraska before all is said and over.

12Z Euro is very strong with that Nor 'Easter, WOW! Might be overdone, we'll see but the storm is there. I like that look by the end of the run for the possible 20th system. Nice overrunning look ahead of the next arctic blast of cold air.

tron777 wrote: ↑Sat Dec 10, 2022 2:11 pm 12Z Euro is very strong with that Nor 'Easter, WOW! Might be overdone, we'll see but the storm is there. I like that look by the end of the run for the possible 20th system. Nice overrunning look ahead of the next arctic blast of cold air.

Les you mentioned earlier this week the Nor 'Easter was key in bringing down the cold air and that is correct. Sure we get some cold air behind the front but after the storm leaves the northeast USA more cold will be available to head this way. I love the step down approach when cold air is moving in as this usually has much more staying power. No doubt plenty of snow this week in the northern plains and parts of the central plains. Cold air will have no problem making inroads over the next few weeks.

Good evening all! Just watching the ole Happy Hour GFS coming in here. It's always good for a laugh in the extended range. For Wed's system... the model has 2" of rain now at CVG since it is very very slow at bringing the frontal boundary thru. Slower then the rest of the models. If the other models are to be believed, you would need POPS for Tues night after midnight all day Wed and wrapping up Wed night. If you believe the GFS then you need likely POPS Wed and Thurs both. If this pans out, my original 1-2" call was perfect. But I already backed down yesterday to 1/2" to 1" because I agreed with Tim's thought process of t-storms across the SE US robbing us of some moisture. I think Tim is right and has been right all along so I changed. Whatever happens, happens and the bottom line here is that the Nor 'Easter is going to develop. The 12Z GFS finally caught on and the new 18Z run here is also showing it but it's really still too progressive.

Good morning everyone! Will we see any peaks of sun today? We should this afternoon but I wouldn't count on a lot of it. Sunshine prospects continue to look the best for Monday so soak it up! Clouds increase Tuesday ahead of next week's big storm. If you have outdoor plans, say getting a Christmas Tree, decorating / hanging lights, need to do any last minute yard work, etc... the next 3 days is your window of opportunity to get 'er done! After that we get wet and then winter comes in and it is here to stay for a while in my opinion.

Timing wise next week... rain should arrive sometime after midnight Tues night. It continues to look like a slow Wed morning commute. We should see periods of rain continuing Wed night and into Thurs as well. By then the East Coast low begins to develop as the primary low over the Ohio Valley dies. Once the front passes by Thurs afternoon, temps will begin to crash. Rainfall amounts continue to look very good to pull us out of the drought. An inch plus easy by the looks of things should occur. My original call, I should have stuck with it LOL Anyway, we get the dry slot and then wrap around snow showers Friday and Sat on the backside of the Mid ATL and Interior New England snow storm. We will get the upper level low here to cause some festive flakes! No idea of we see accumulation out of it this far away but I suppose Fri night would be a potential window. Ground is warm still so I don't think during the day Fri we will see much. Yeah if it comes down heavy a car topper / grassy dusting is possible. Then when it lets up or stops, the snow melts. It should be one of those deals.

With the more sustainable cold pattern, the ground will be ready to receive the next system whenever it occurs so that every flake will stick! I'm still watching the period around the 20th, Christmas Eve / Day and probably another chance even after that. We will have a split jet stream pattern with the STJ bringing in the moisture from the south. The polar jet will continue sending down arctic fronts with shots of cold air. With the blocking pattern, we should be able to get the jets to phase a time or two one would think during the 20-31st period. We shall see as usual but that is my current thinking.

Good Morning Les and great post as usual. I still like below 1 inch in the rainfall total and yes if the front slows up in the right place somebody can get some higher totals but have no ideal where that may be and we have two main areas of energy with one the upper plains and one that should be south of here so when that happens I try and go lower with the totals. Will look at the noon models when they come in and then football Sunday.

tpweather wrote: ↑Sun Dec 11, 2022 10:10 am Good Morning Les and great post as usual. I still like below 1 inch in the rainfall total and yes if the front slows up in the right place somebody can get some higher totals but have no ideal where that may be and we have two main areas of energy with one the upper plains and one that should be south of here so when that happens I try and go lower with the totals. Will look at the noon models when they come in and then football Sunday.

Good morning Tim! Yeah... a very important football Sunday for me. I need a win and some help from above to try and make the playoffs beginning next week in my fantasy football league.

Weather wise... 12Z NAM has 0.57" ending 7pm Wed (that is when the model stops running at 84 hours). The front looks to be past us but a new low develops down in MS so that is the Thurs rain threat. So yes... two periods of rain are expected. The first late Tues night and Wed with the front and occluding low to our west. Followed by the second low working up the front which begins the new primary low into the OV. That one then weakens as a third low develops for the Eastern Seaboard locations while we get the upper low on the backside Fri into Sat with snow showers. I think we've got the storm evolution down pat at this point in time. Just a few tweaks with timing and track are about all that remain.

tron777 wrote: ↑Sun Dec 11, 2022 10:24 am

tpweather wrote: ↑Sun Dec 11, 2022 10:10 am Good Morning Les and great post as usual. I still like below 1 inch in the rainfall total and yes if the front slows up in the right place somebody can get some higher totals but have no ideal where that may be and we have two main areas of energy with one the upper plains and one that should be south of here so when that happens I try and go lower with the totals. Will look at the noon models when they come in and then football Sunday.

Good morning Tim! Yeah... a very important football Sunday for me. I need a win and some help from above to try and make the playoffs beginning next week in my fantasy football league.

Weather wise... 12Z NAM has 0.57" ending 7pm Wed (that is when the model stops running at 84 hours). The front looks to be past us but a new low develops down in MS so that is the Thurs rain threat. So yes... two periods of rain are expected. The first late Tues night and Wed with the front and occluding low to our west. Followed by the second low working up the front which begins the new primary low into the OV. That one then weakens as a third low develops for the Eastern Seaboard locations while we get the upper low on the backside Fri into Sat with snow showers. I think we've got the storm evolution down pat at this point in time. Just a few tweaks with timing and track are about all that remain.

Hey Les and all about timing as well. I agree with the second low developing on the front to the south of us. When that weakens will determine how much rain we get. If you are in the correct place with the heaviest rain falling before it transfers I can see higher totals. So I believe a lock to get .5-1.0 but would it surprise me to see somebody in the Ohio Valley get more and the answer is no. What I like about this pattern is we are not getting the boatload of cold at first but back to more seasonal are slightly below at first but the cold then starts heading southward next week and hopefully the STJ will play nicely with us. Going to be a boundary between the leftover warmth and the arriving colder air and my guess at this time is in the Ohio or Tn valley. Still have plenty of time to iron out each system but from this far out I like the pattern.

I would expect this pattern to last 3 and maybe 4 weeks depending on how much snow falls in the USA. Then a January thaw probably in that Jan9-16th range as cold air rebuilds up north. That is how I see things at the moment and ready for those long nights lol.

tpweather wrote: ↑Sun Dec 11, 2022 10:32 am

tron777 wrote: ↑Sun Dec 11, 2022 10:24 am

tpweather wrote: ↑Sun Dec 11, 2022 10:10 am Good Morning Les and great post as usual. I still like below 1 inch in the rainfall total and yes if the front slows up in the right place somebody can get some higher totals but have no ideal where that may be and we have two main areas of energy with one the upper plains and one that should be south of here so when that happens I try and go lower with the totals. Will look at the noon models when they come in and then football Sunday.

Good morning Tim! Yeah... a very important football Sunday for me. I need a win and some help from above to try and make the playoffs beginning next week in my fantasy football league.

Weather wise... 12Z NAM has 0.57" ending 7pm Wed (that is when the model stops running at 84 hours). The front looks to be past us but a new low develops down in MS so that is the Thurs rain threat. So yes... two periods of rain are expected. The first late Tues night and Wed with the front and occluding low to our west. Followed by the second low working up the front which begins the new primary low into the OV. That one then weakens as a third low develops for the Eastern Seaboard locations while we get the upper low on the backside Fri into Sat with snow showers. I think we've got the storm evolution down pat at this point in time. Just a few tweaks with timing and track are about all that remain.

Hey Les and all about timing as well. I agree with the second low developing on the front to the south of us. When that weakens will determine how much rain we get. If you are in the correct place with the heaviest rain falling before it transfers I can see higher totals. So I believe a lock to get .5-1.0 but would it surprise me to see somebody in the Ohio Valley get more and the answer is no. What I like about this pattern is we are not getting the boatload of cold at first but back to more seasonal are slightly below at first but the cold then starts heading southward next week and hopefully the STJ will play nicely with us. Going to be a boundary between the leftover warmth and the arriving colder air and my guess at this time is in the Ohio or Tn valley. Still have plenty of time to iron out each system but from this far out I like the pattern.

I would expect this pattern to last 3 and maybe 4 weeks depending on how much snow falls in the USA. Then a January thaw probably in that Jan9-16th range as cold air rebuilds up north. That is how I see things at the moment and ready for those long nights lol.

I agree Tim... we will have seasonal cold as you said by Fri and Sat of next week. Then, we'll see if we can cash in ahead of the arctic plunge that comes as we approach Christmas. I think a chance at a big storm is there for someone in the Eastern US. We just have to see how the PNA behaves and where / when the jets phase.

12Z GFS has changed its solution yet again for the storm next week. 1.35" of rain at CVG and that is not the problem. It is more progressive again and blasts the front thru Thurs morning with no secondary low development for the OV. This model just isn't handling the blocking pattern correctly whatsoever. It does pop the East Coast low so it at least it sees that part of the storm's evolution. I just don't think this is the right solution. I like the solution I outlined in my earlier post this morning. It just makes more sense to go slower with multiple lows in this intense blocking pattern we are now in. If I am right, the EC Low will develop much further south then where the GFS has it.

tron777 wrote: ↑Sun Dec 11, 2022 11:10 am 12Z GFS has changed its solution yet again for the storm next week. 1.35" of rain at CVG and that is not the problem. It is more progressive again and blasts the front thru Thurs morning with no secondary low development for the OV. This model just isn't handling the blocking pattern correctly whatsoever. It does pop the East Coast low so it at least it sees that part of the storm's evolution. I just don't think this is the right solution. I like the solution I outlined in my earlier post this morning. It just makes more sense to go slower with multiple lows in this intense blocking pattern we are now in. If I am right, the EC Low will develop much further south then where the GFS has it.

Tell you truth Les either one that plays out is not a overall problem. I still have reservations about the higher rain totals and the main reason is we have divided energy and that always bothers me when trying to make a forecast. Can we get the higher totals and yes but I still believe we need the front to stall or at least slow down and on this one Les I am just not sure if it slows down enough to get the heavier rain. Either way I expect a low pressure to form off the east coast but I am not into the storm of the century by any means and one reason is the NAO which is really negative early in the week heads towards neutral so this tells me that yes a storm forms but still may be rather aggressive. No its not like the gfs from the past few days where it showed everything heading out to see but I don't believe its a storm that last a long time on the east coast.

What I do like for us though is after we have this pattern settled in the GOM is still loaded and usually we see a piece of energy develop close to New Mexico and this rides the temp boundary at the same time a much bigger push of cold air is headed this way. Again no way to time that out this early but the potential to have a bigger storm east of the Mississippi starting around the 20th or 21st looks wonderful this far out. Does not mean we get hit but potential that someone will and we just need see how this pans out. After that we have more energy that should keep the pattern busy through the holiday season.

tpweather wrote: ↑Sun Dec 11, 2022 11:37 am

tron777 wrote: ↑Sun Dec 11, 2022 11:10 am 12Z GFS has changed its solution yet again for the storm next week. 1.35" of rain at CVG and that is not the problem. It is more progressive again and blasts the front thru Thurs morning with no secondary low development for the OV. This model just isn't handling the blocking pattern correctly whatsoever. It does pop the East Coast low so it at least it sees that part of the storm's evolution. I just don't think this is the right solution. I like the solution I outlined in my earlier post this morning. It just makes more sense to go slower with multiple lows in this intense blocking pattern we are now in. If I am right, the EC Low will develop much further south then where the GFS has it.

Tell you truth Les either one that plays out is not a overall problem. I still have reservations about the higher rain totals and the main reason is we have divided energy and that always bothers me when trying to make a forecast. Can we get the higher totals and yes but I still believe we need the front to stall or at least slow down and on this one Les I am just not sure if it slows down enough to get the heavier rain. Either way I expect a low pressure to form off the east coast but I am not into the storm of the century by any means and one reason is the NAO which is really negative early in the week heads towards neutral so this tells me that yes a storm forms but still may be rather aggressive. No its not like the gfs from the past few days where it showed everything heading out to see but I don't believe its a storm that last a long time on the east coast.

What I do like for us though is after we have this pattern settled in the GOM is still loaded and usually we see a piece of energy develop close to New Mexico and this rides the temp boundary at the same time a much bigger push of cold air is headed this way. Again no way to time that out this early but the potential to have a bigger storm east of the Mississippi starting around the 20th or 21st looks wonderful this far out. Does not mean we get hit but potential that someone will and we just need see how this pans out. After that we have more energy that should keep the pattern busy through the holiday season.

Yeah I'm not expecting the Nor 'Easter to be the storm of the century either. Something like 6-12" is just a run of the mill or an avg storm for them. I believe that the GFS is just being the GFS at this point. We are on the same page though for what we think may happen there after. The pattern should be prime in my opinion too starting around the 20th thru ???

The 12Z CMC is slower with the front even though it's not popping the OV Low on this run either. But I think at least the model has the speed of the storm progged better due to the blocking.

12Z GEFS Mean continues to handle the system for next week as I am currently envisioning with a total of 3 lows. The first gets to the IA / MN boarder and dies which is much further south then before. This is due to the blocking and I think the GEFS on this run is handling it much better. Then we get the OV Low that does as the coastal low develops much further to the south as a result over the Carolinas vs the Delmarva should the secondary OV low not develop. To your point Tim it doesn't impact our forecast all that much in a direct sense, but this does have an influence on the pattern and future storm systems that come down the line.

Mods are just doing the usual meeting in the middle at this range. Dropping the big Neaster. There just isn't the cold air in place for that kind of storm

Bgoney wrote: ↑Sun Dec 11, 2022 12:01 pm Mods are just doing the usual meeting in the middle at this range. Dropping the big Neaster. There just isn't the cold air in place for that kind of storm

Not for the Coast, 100% agree. The winners should be interior New England esp in the higher elevations of the mountains.

12Z Euro has the 2 low idea still with the cold front coming thru around late morning to midday on Thursday with falling temps in the afternoon. Total rain for CVG is 1.67" Then, the EC Low pops over Central NC by Thurs evening. Then Interior New England up into Maine gets some snow. For us... the Euro is actually much different today with the backside part. Recall my idea has been with the upper low to produce snow showers on Fri and Sat. The GFS got rid of that idea and instead a southern stream system came out missing us to the SE with some light snow in KY by Sunday the 18th. The 12Z Euro today is trying to do something like that too but the difference here is the energy gets shredded thanks to the cold air just overwhelming everything so thus, cold and dry. I am not buying into any solution yet for next weekend and beyond. Kind of still in watch and wait mode there.

Need a break from the first half. Next weekend and I believe really we just see some snow showers and flurries. Believe not until the start of next week that we see systems starting to take shape once again. Could see a dusting next week at times but not expecting anything to amount to much. Will update later and need another beer after that 1st half.

Eps 850s from the 17th to 26th

Bgoney wrote: ↑Sun Dec 11, 2022 4:31 pm Eps 850s from the 17th to 26th



ecmwf-ensemble-c00-namer-t850-1670760000-1671278400-1672056000-20.thumb.gif.8df0054bec7072de636bc99e53d86fa0.gif

When you watch that loop the 850s get close to zero for Cincy around the 22-23rd. Probably indicative of a winter storm occurring around that time. There is def a signal there on most Ensemble guidance. We'll see!

18Z GFS does not have all three lows, just two. It is back to showing the back end snow shower chance with the upper low again at least for Friday evening / night.

Good morning all! Not a lot of change to report for this week. We've been discussing this next system and the pattern change that it brings for quite sometime. The light is now at the end of the tunnel! Today and tomorrow, no problems for outdoor plans. The game is over after that with rain coming later Tues night and esp on Wed. Wed AM commute will be slow as I've mentioned with the heavy rain around. We will see a small break then another batch of rain as the cold front comes thru on Thursday. Models appear to have abandoned the 3 low idea and we're back to just 2. We get the primary that dies in the Lakes / OV then the secondary low taking over for interior New England and the mountains to get a nice snow by the end of this week or so. For us, temps crash on Thurs once the front passes and winter comes in! Highs in the 30s and lows in the 20s are expected from Friday onwards. I still believe we will see back lash snow showers on Friday with no issues expected. We'll see if they linger into Sat or not... models are beginning to back away from it lingering so much.

Then what happens? I've been eyeballing the period around the 20th for a while now but a much stronger signal I think is developing for the 12/21 thru 12/23 period for a major winter storm right before Christmas. Way too early to know the result for us, but it's really looking like a period to watch on most OP's and Ensemble models. If this system forms and if we do cash in, we will 100% see a White Christmas. If we see nothing, or rain from it then well, it's another Brown Christmas as usual. We'll see guys... that'll be an interesting storm to track esp once we get past Wednesday and Thursday's system. We should have a better idea of the flow once the cold settles in.

tron777 wrote: ↑Sun Dec 11, 2022 11:10 am 12Z GFS has changed its solution yet again for the storm next week. 1.35" of rain at CVG and that is not the problem. It is more progressive again and blasts the front thru Thurs morning with no secondary low development for the OV. This model just isn't handling the blocking pattern correctly whatsoever. It does pop the East Coast low so it at least it sees that part of the storm's evolution. I just don't think this is the right solution. I like the solution I outlined in my earlier post this morning. It just makes more sense to go slower with multiple lows in this intense blocking pattern we are now in. If I am right, the EC Low will develop much further south then where the GFS has it.

weather willy was saying the same thing in his early morning video

Good Morning and hope everyone had a nice weekend. Been doing a little painting inside the house so not caught up on anything this morning. Models are starting to come out as I post this but really the system for the middle of the week and how much rain will fall is probably the top issue. Still going .5-1 but again I understand how we get over and inch but that is going to be timing with the second round of rain that gets in here probably Wednesday evening is my guess. Then the cold front comes through with the normal snow flurries and a few snow showers Friday and Saturday. Then usually in these types of pattern you get another system to form in the southern plains area.This usually occurs about 2-4 days after the cold front comes through. Models usually have a horrible and I mean horrible time in picking up these systems and not sure why because it happens I would say 75 p/c of the time. So many times they will show nothing even 3-5 days before and boom they finally catch on. Can't blame any certain model because they all tend to have this problem. After that more cold through the holidays and will watch the energy coming into the southern USA plus always some pieces of energy that comes down with the polar jet and normally these have less in the way of precip but if they can hook up with the southern friend then you can get a decent winter event. I will post more later after the models come out and see how much I can disagree with them lol.