January 2023 Weather Discussion

[tron777]

I'll go ahead and get our new monthly thread going since the NYE rain maker ends early on NYD. Then we've got another rain maker to track around the 3-5th. Then the 7-8th possibly. After that do we turn cold again? I am seeing a lot of signals that say YES from the Ensemble Guidance. I'm watching a lot of things right now for January. The MJO. Is the La Nina finally weakening? Do we see a SSW event that leads to a disrupted PV for late Jan and Feb wintry fun? Lots of interesting things to discuss guys despite the temporary break in our wintry pattern that is coming for early in the month.

[tpweather]

Good Morning Les and plenty of items to talk about this week leading up imo to a active January. No doubt the lower latitudes will warming up as the polar vortex strengthens. Talking about La Nina weakening for it seems like years but hopefully this is the case and usually at the start and end of these events you get some wild weather. We just went through a major event and can we expect more the next few months. Sure more pieces of the puzzle to look at but I believe this is going to be a wild couple of months before we get to spring. I am leaving for SC on Tuesday and may need to get my shorts out as I would not be surprised to see a few days in the 70's down there this weekend. Hopefully when I get back on the 4th of January we will be in full winter mode as by then the models will start to see the return of winter. Usually this starts out west and we slowly push things east with each storm. Hope we get some rain but not to much of a good thing would be nice.

[tron777]

The sooner you come back, the sooner the cold returns you know. At least you should have some much better weather to travel in vs what folks have been dealing with over the past several days. The EPS looks really nice with the Aleutian Low pattern I've been talking about which pumps up the ridge in AK and Canada. That ridge connections with the -AO and -NAO again for blocking over the top. We know we have an active jet stream across the south. I'm truly salivating over the prospects Tim in about 2 weeks from now. Hope our good long range calls keep working out!

[tpweather]

The sooner you come back, the sooner the cold returns you know. At least you should have some much better weather to travel in vs what folks have been dealing with over the past several days. The EPS looks really nice with the Aleutian Low pattern I've been talking about which pumps up the ridge in AK and Canada. That ridge connections with the -AO and -NAO again for blocking over the top. We know we have an active jet stream across the south. I'm truly salivating over the prospects Tim in about 2 weeks from now. Hope our good long range calls keep working out!

Great Post Les and you hit all the key points imo. If that was the case Les about the sooner I return the sooner the cold returns I would come back Wednesday lol. In November we talked about the mid-December cold spell and the models were just a little to quick. How quickly does the cold return this time and always good to be patient but that Aleutian Low may come around rather quickly this time.

[tron777]

The sooner you come back, the sooner the cold returns you know. At least you should have some much better weather to travel in vs what folks have been dealing with over the past several days. The EPS looks really nice with the Aleutian Low pattern I've been talking about which pumps up the ridge in AK and Canada. That ridge connections with the -AO and -NAO again for blocking over the top. We know we have an active jet stream across the south. I'm truly salivating over the prospects Tim in about 2 weeks from now. Hope our good long range calls keep working out!

Great Post Les and you hit all the key points imo. If that was the case Les about the sooner I return the sooner the cold returns I would come back Wednesday lol. In November we talked about the mid-December cold spell and the models were just a little to quick. How quickly does the cold return this time and always good to be patient but that Aleutian Low may come around rather quickly this time.

What's really interesting to me is the repetitiveness of the pattern. Recall back in October we got that early cold snap. Then mega warmth to start November, then we had another cold shot and a touch of snow too. Then we warmed into early December. Then boom! The pattern changed on the 15th and we got big time cold and a blizz out of the deal including a White Christmas. Here comes the warmth again for late Dec and early Jan. Signs are the cold comes back in about 2 weeks from now. What'll happen this time when climo is in our favor? It's going to get fun on our forum again! People better rest up.

[tpweather]

Les getting this repeating pattern helps so much in long term forecasting. Timing can be off some but the pattern itself is so much easy to recognize. Getting cold in mid-late January is always nice around here plus the GOM really starts to wake up in January. The second half of December is usually bad for getting tons of moisture from that region but like I mentioned once you move forward in January and head towards spring the GOM usually wakes up and then we have a better shot of some heavier snows.

[tron777]

Here's a nice look at the Pacific Jet retracting allowing the ULL off the West Coast to retrograde to the Aleutians.

GEFS Jet.gif

[tpweather]

Nice graphic Les. When the cold pattern returns we need some things to change to make it a pattern that lasts somewhat longer. The latest attach was a northwest to southeast surge of cold air so you so places like Florida getting really cold but places in the southwest and south central states kept pretty mild. We need the cold next time to aim more for the that area and this is how you keep the cold around for a much longer period.

[tron777]

Nice graphic Les. When the cold pattern returns we need some things to change to make it a pattern that lasts somewhat longer. The latest attach was a northwest to southeast surge of cold air so you so places like Florida getting really cold but places in the southwest and south central states kept pretty mild. We need the cold next time to aim more for the that area and this is how you keep the cold around for a much longer period.

It's a balancing act. Too far West and you get cutters. Too far East and we are cold and dry. You get it just right and it can be a very nice pattern as you said. It's a bit early to get the angle of attack correctly IMO on guidance, but in the next week, that should come better into focus.

[tron777]

I am seeing a concerning trend developing in terms of upcoming rainfall. Models are taking on a look where we get a slow moving frontal boundary swinging thru. With each successive low pressure, that boundary sinks further and further to the SE. Eventually we should see some snow out of it by week 2 in January as we've been discussing. Until then, we've got at least 3 potential rain makers to come thru. I could see 2-3" of rain potentially coming from NYE thru 1/7 or so. We are coming out of an arctic pattern. The ground is frozen and will take a few days to thaw. How much can the ground handle once the current snowpack soaks in? How much for NYE / NYD and the couple of early January cutters I am expecting. Need to keep that one eye open look for localized flooding concerns until the cold returns.

[tron777]

Fantasy range but a scenario as the GFS is showing on this run would be awful. On the 7-8th, the model has 0.64" of rain then around a 1/2" of QPF falling as snow with falling temps. Then all of that wetness and wet snow freezes up into a glacier. Lovely! A scenario such as this wouldn't be surprising given the gradient pattern I have talked about.

[Bgoney]

Alright a Jan thread!!! Like to comment about MJO, easterrlies near the dateline have been impressive and look to remain so, that can only mean the MJO signal will get beaten down again or die off in the pac , which the mods are showing , so I'm not expecting the MJO to help in regards to a turn back to wintry weather after the first 10 days of Jan. So I'm not sure how long this spell will last. And what turns the tide back to wintry conditions in the OV?

u.anom.30.5S-5N.gif

sst_wind_5day_drupal.png

[tron777]

Alright a Jan thread!!! Like to comment about MJO, easterrlies near the dateline have been impressive and look to remain so, that can only mean the MJO signal will get beaten down again or die off in the pac , which the mods are showing , so I'm not expecting the MJO to help in regards to a turn back to wintry weather after the first 10 days of Jan. So I'm not sure how long this spell will last. And what turns the tide back to wintry conditions in the OV?

From what I have been reading, increased blocking over the Ural Mountains and Scandinavian Ridging are going to be pressing up against the PV again causing it to stretch kind of like what we just saw. In addition and this an unknown for the 2nd half of the winter, but if we also see a SSW event what will that do for later in Jan and into Feb? For now... let's see if that blocking comes back by the 10th. We've been down that road before and have lost. But at the same time, you need something to disrupt the PV and to challenge the background La Nina state.

[tpweather]

Bgoney a wonderful post by you and over the next few days once I get back in SC I will study this part of the puzzle. I was wrong when I thought this current cold wave would last into the first week of January before we had the thaw so I must go back and study the past week and try and understand why I was incorrect . You tend to learn when forecast mistakes are made plus at least I know I do more research to help me understand what I missed. Sometimes you can rely too much on recent success and I had a wonderful November and first 3 weeks of December where everything that was pitched my way looked like a beach ball. The past few days though that same pitch is looking more and more like a marble in the longer term forecasts and you don't want to get into a long term slump.

[tpweather]

Of course already studying the past and see what the future may hold. Earlier in December I talked about how it was not your normal southeast ridge that we see many times in the winter. This kept the south central states from getting many fronts through that area and left them rather mild and dry during the late fall. The ridge was near the Yucatan and not near the Bahamas and another reason cold made it really far south in Florida and the Bahamas and other areas in the Caribbean especially the further east. This time we will be getting a more lets say normal southeast ridge and what is the difference and for one thing the GOM is wide open and systems can dig further into the south central part of the country. This will of course take sometime with each passing system making inroads into that ridge. So yes until probably the 7th or 8th any precip for the most part will be in the form of rain even though there is always a chance to get a little winter precip on the back end but usually this means snow flurries at best. So this part of the next 2 weeks or so makes sense imo and especially the pattern looks to take on that shape. Next will be how long does it take to break down the pattern and there is more than one way to skin a cat and will look at those options over the next 3-4 days.

[tron777]

Bgoney a wonderful post by you and over the next few days once I get back in SC I will study this part of the puzzle. I was wrong when I thought this current cold wave would last into the first week of January before we had the thaw so I must go back and study the past week and try and understand why I was incorrect . You tend to learn when forecast mistakes are made plus at least I know I do more research to help me understand what I missed. Sometimes you can rely too much on recent success and I had a wonderful November and first 3 weeks of December where everything that was pitched my way looked like a beach ball. The past few days though that same pitch is looking more and more like a marble in the longer term forecasts and you don't want to get into a long term slump.

That thought process would have worked fine. The pattern should have lasted thru Week 1 in Jan then the thaw instead of it happening in reality a week earlier. This is due to the big blizzard we just had. That monster low over SE Canada is breaking down the blocking pattern. This big storm was so massive and large that it has now altered the hemispheric pattern temporarily back to the typical La Nina base state which is mild and wet for us. We will get out of it in Week 2 if the Ensemble guidance is correct with the blocking coming back as I have been talking about.

[tron777]

Fantasy range but a scenario as the GFS is showing on this run would be awful. On the 7-8th, the model has 0.64" of rain then around a 1/2" of QPF falling as snow with falling temps. Then all of that wetness and wet snow freezes up into a glacier. Lovely! A scenario such as this wouldn't be surprising given the gradient pattern I have talked about.

Euro is showing hints at this set up as well for Days 9-10. We get a big cutter around the 3-4th then the next low rides up the front to our SE. Rain to snow the Euro and GFS are both showing. We will see if that turns out to be rain and it gets pushed back to the 9-10th which was my original call anyway. Or, does the pattern change a touch faster? I will be watching it this week.

[tpweather]

Les great point about the massive low over eastern Canada. That was one of the reason I thought the pattern would break down but was amazed how quickly that happened. I will need to at some of those late 70's winters and yes we seem to have pattern changes as well but the problem back then was we had such a snow pack over a large part of the country and though we have a nice area at the moment its not very deep compared to those winters so getting the return to warmth is much easier this go around.

[tron777]

Les great point about the massive low over eastern Canada. That was one of the reason I thought the pattern would break down but was amazed how quickly that happened. I will need to at some of those late 70's winters and yes we seem to have pattern changes as well but the problem back then was we had such a snow pack over a large part of the country and though we have a nice area at the moment its not very deep compared to those winters so getting the return to warmth is much easier this go around.

The snow pack is decent with regards to aerial coverage yes, 53% as of yesterday. But that is correct, The snow depth is way more important. The greater the depth, the more of the suns energy it takes to melt it away. Thinner snow cover as you know can melt off within a days time. We have a frozen ground going for us so IMO our snow cover should last until Wed afternoon. Sun and 40s should polish it off rather quickly.

[tron777]

A nice look continues on the EPS this afternoon with a possible +PNA. Low chance of a +PNA in my opinion. GEFS and GEPS both have the blocking on top, but only the EPS shows a +PNA to go along with it. I'm confident on the blocking returning but not the +PNA. Bgoney's post on the MJO would argue against a +PNA as well. At any rate, the signal still looks good sometime between the 7-10th for a storm.

EPS.png

[Bgoney]

Sometimes these ALeutian Low patterns are stubborn to break down and this looks to extend into PNA territory . The good thing is from what ive read this is a wave 1 pattern hit on the PV , so even if that pattern last longer in Jan , it could be good for Feb pattern

[tron777]

Sometimes these ALeutian Low patterns are stubborn to break down and this looks to extend into PNA territory . The good thing is from what ive read this is a wave 1 pattern hit on the PV , so even if that pattern last longer in Jan , it could be good for Feb pattern

Yes... and it kind of ties into that possible SSW event as well. Feb could get very interesting. For now, I still like where January is headed after the first week. We may not get the +PNA (we only had a temp. spike for the Christmas Blizzard) but timing as you know is everything. If we get another well timed PNA spike then it becomes a workable pattern for another storm system again. Something like that occurring again (The PNA spike) wouldn't be surprising. We just cannot sustain one in a La Nina of course.

[tron777]

Good morning all! 12Z GFS has the first rain maker pulling away on NYD especially early. Next rain maker moves in by the night of Jan 2nd and into the 3rd. Another good soaking is likely. Then one more small batch on the 4th then it turns cold again. Models will bicker back and forth as to when the colder air returns. My original call was for Jan 9-10th timeframe and I will keep it as such until we get a little closer. Still liking a storm to usher in the colder pattern as well in that Jan 7-10th timeframe. Whether or not we cash in for snow lovers remains to be seen but that period is the next one to watch for snow lovers in my opinion.

[tron777]

12Z GEFS has a nice signal for a good sized storm in that 7-10th period. Solutions range from a Cutter (rain ending as flakes) to an Apps runner to an Upper Low like what the 0Z and 6Z OP GFS runs had. 12Z lost it of course as it typical for OP runs this far away.

[tron777]

12Z Euro is in agreement with the GFS of the next Cutter coming the night of 1/2 and a wet 1/3 upcoming. Front comes thru but stalls then a wave from the Gulf rides up along the front around the 5th. I've seen this solution a few times from past GFS runs.