Absolute Vorticity

I agree... yes I get excited because I do love snow so much and I've always admitted that I am a huge snow weenie. But those folks do it for rating and / or click bait.

Anyway... 21 here this morning, pretty nice for December. Just a small chance for rain around Christmas Time and a warm up by then. Otherwise the short term continues to be quiet. Still looking to ramp up rain wise between the Christmas and New Year's period with another one of those stalled out frontal boundaries and waves of low pressure moving along. Can someone get lucky esp northern posters with some wintry weather? That is possible as long as we don't see an amp'ed up system, then it will cut.

We of course continue to see how early Jan is going to unfold.

Good Morning and a nice cold start to the day and yes in the normal range for this time of year. Most of the week just your normal late December weather which is usually cold and dry. Then the two days I would love to see cold will be the mildest days and that is the 24th and 25th.

I saw where Barrow,Alaska had some decent snow in the last 12 hours or so and temp was up to 32 degrees. That is very uncommon on both the amount of snow which was probably a couple of inches plus my guess is near a record high for them. Much of the remainder of Alaska continues to get hit with snow and Fairbanks which in the last couple of storms was missing some of the bigger snows got hit big this time around.

Siberia and yes had a milder period for them has got cold again and saw -62 as the coldest I can find. Some forecasts over the next 7-10 days have temps near -90 and that would keep the beer cold for quite awhile. So the extreme weather is also hitting the polar regions.

What does all this mean for us locally and in the next 2 weeks maybe not the record highs we saw before but more of a nice warm up,rain and followed by a normal brand of cold for this time of year.

The mjo and what is going on with that is still quite the mystery and it should be as it was stuck in phase 4 though mild through much of November and the models back in Oct did not show that and the recent couple of weeks we made that quick stride to phase 6 but have been stuck in phase 6 for the most part though the mjo forecast had it going through phase 7 and finally getting to phase 8. This tells me patterns are being very stubborn this fall and early winter season. Many times you will see a big storm or two that will change the pattern but we have seen a couple of big storms the past couple of weeks and again the pattern continues status quo.

Can we look back and say La Nina had an uptick the past 6 weeks or so and the pattern no doubt is saying yes. If that would continue then no reason for the pattern to go in a 180 turnaround. Saying that a weakening of the La Nina could bring the change around and no doubt something to look at the next couple of weeks.

I believe patterns have a life of their own and they make forecasters and models look silly sometimes. I still believe a dump of cold is coming this way and when it happens expect a nice 3-4 week period of cold and hopefully snow. Many old time met's will always talk about a January thaw which for many years seem to happen quite often. In recent years the thaw never happened because it was already mild for much of the winter leading up to mid-January.

As you can see by my post I am trying to figure out what is controlling the pattern around the globe and no doubt a strong PV over the past 6 weeks and that has made the polar regions really cold for an extended period. That is good if we can get the pattern change because cold air source is widely available.

Nice post Tim! Still watching to see how the MJO responds after that Super Typhoon went thru the West Pac. Supposedly 200 dead in the Philippines due to this system. It looks to hit China in a much weakened state coming up so no recurving typhoon with this one. That is a big reason why the cold got delayed until January instead of Christmas to New Year's. Hopefully, it does not get stuck in 7 and keeps moving into 8. Despite the -NAO block, the -EPO block is to the west because of La Nina, you get a raging -PNA and SE ridge. Now, the -NAO might help to temper the SE ridge some which we would need to score. But it's just too early to know how this is all going to play out after Christmas and really low confidence now after the New Year. Things may or may not break our way. Hoping that they do of course but this is no slam dunk by any means. Models are not quite as good in agreement as they were the other day.

Les you mentioned the southeast ridge that is common during La Nina and I believe this season we have had a southwest/southcentral ridge as well and in recent weeks have connected to the southeast ridge which finally got under way in December. We talk about blocking all the time and how if we can get the ridge over the polar regions to connect it can help send the cold air southward and that is correct. What we don't talk about much is what happens when you get these ridges in the southern USA and they connect and this becomes a blocking pattern which makes it much harder for cold air to work southward. We get these ridges in the late spring and summer and this promotes some decent heat waves but getting one in late fall and early winter is one we don't see all that often.

tpweather wrote: ↑Mon Dec 20, 2021 7:42 am Les you mentioned the southeast ridge that is common during La Nina and I believe this season we have had a southwest/southcentral ridge as well and in recent weeks have connected to the southeast ridge which finally got under way in December. We talk about blocking all the time and how if we can get the ridge over the polar regions to connect it can help send the cold air southward and that is correct. What we don't talk about much is what happens when you get these ridges in the southern USA and they connect and this becomes a blocking pattern which makes it much harder for cold air to work southward. We get these ridges in the late spring and summer and this promotes some decent heat waves but getting one in late fall and early winter is one we don't see all that often.

If the blocking over the top can help suppress the SE ridge some, we'd be in line for some west to east moving systems and overrunning events. If it gets destroyed then a nice clipper pattern. Worse case scenario is the -PNA doing the driving of the pattern (thanks to the Nina and MJO) then we get cutters. Literally all options are on the table attm esp for January.

Bgoney mentioned how he saw signs of the La Nina getting strong early on in November and no doubt he was correct. The interesting thing at the time though was the southeast was not in play at all. Matter of fact the southeast USA was very cool for all of November as the ridge was much further west like I mentioned before. In the past two weeks the southeast ridge made up for lost time and part of that was a really strong tropical system off the northeast coast of South America which built up heights north of there into the southeast part of the USA. So we had the more typical southeast ridge that you get with a La Nina plus added heights from tropical systems to the south and this spelled trouble for severe weather in the central USA. 20/20 vision is always nice to have but when I looked at the past 6 weeks or so this is how it played out imo.

tpweather wrote: ↑Mon Dec 20, 2021 7:56 am Bgoney mentioned how he saw signs of the La Nina getting strong early on in November and no doubt he was correct. The interesting thing at the time though was the southeast was not in play at all. Matter of fact the southeast USA was very cool for all of November as the ridge was much further west like I mentioned before. In the past two weeks the southeast ridge made up for lost time and part of that was a really strong tropical system off the northeast coast of South America which built up heights north of there into the southeast part of the USA. So we had the more typical southeast ridge that you get with a La Nina plus added heights from tropical systems to the south and this spelled trouble for severe weather in the central USA. 20/20 vision is always nice to have but when I looked at the past 6 weeks or so this is how it played out imo.

The numbers aren't showing a strong Nina but the atmospheric response has been for December.

tron777 wrote: ↑Mon Dec 20, 2021 8:10 am

tpweather wrote: ↑Mon Dec 20, 2021 7:56 am Bgoney mentioned how he saw signs of the La Nina getting strong early on in November and no doubt he was correct. The interesting thing at the time though was the southeast was not in play at all. Matter of fact the southeast USA was very cool for all of November as the ridge was much further west like I mentioned before. In the past two weeks the southeast ridge made up for lost time and part of that was a really strong tropical system off the northeast coast of South America which built up heights north of there into the southeast part of the USA. So we had the more typical southeast ridge that you get with a La Nina plus added heights from tropical systems to the south and this spelled trouble for severe weather in the central USA. 20/20 vision is always nice to have but when I looked at the past 6 weeks or so this is how it played out imo.

The numbers aren't showing a strong Nina but the atmospheric response has been for December.

I used the wrong word for La Nina getting strong and should have said La Nina is getting stronger. La Nina will go down as a weak episode but again you have periods where it gets stronger for a period of time and I believe that is what happen but I also believe we will soon be getting into a period where it weakens. Will that weakness be a smooth ridge toward neutral or will it weaken just as quickly as it rose.

Down to 22 here

If the tellies are correct and sometimes the data is behind the pattern then the AO has peaked and the NAO is peaking. If both of these move as the models show then much of January will have both in the negative area which bodes well for colder weather. Keeping the nao slightly negative is better in terms of storminess for us and a stronger nao of course helps out the east coast. The ao which if becomes to negative can give us a cold and drier outlook and not a fan of the cold without the snow.

tpweather wrote: ↑Mon Dec 20, 2021 8:46 am If the tellies are correct and sometimes the data is behind the pattern then the AO has peaked and the NAO is peaking. If both of these move as the models show then much of January will have both in the negative area which bodes well for colder weather. Keeping the nao slightly negative is better in terms of storminess for us and a stronger nao of course helps out the east coast. The ao which if becomes to negative can give us a cold and drier outlook and not a fan of the cold without the snow.

I don't foresee a cold and dry pattern with the PNA being negative. That should continue the storm parade. Hoping that the blocking does suppress the storm track further south. Then we can cash in.

Looks like models are speeding up the next system to Christmas Eve so falling temps on Christmas Day. 60s aren't going to happen at this point anyway, Probably in the 50s then falling.

GEFS and GEPS were nice today for early January on the 12Z runs. SE ridge gets flattened pretty good and the Canadian is colder because it gets more of the ridging up into AK. EPS shows the ridge flattening then rebuilds it towards end of Dec, Have not seen 10 to 15 day yet on the EPS for early January. So the differences are in the MJO. Euro guidance keeps it in 7 Aussie get it to 8. Whose going to win? We either keep up the same pattern or go into a better one. We'll see...

Lotta model chaos here.

Euro weeklies isn't horrible. Cold shots. probably a little SDE ridge too. But not unworkable. Thru mid January. MJO def getting stuck in Phase 7 n the Euro guidance.

Hazardous Weather Outlook

Hazardous Weather Outlook
National Weather Service Wilmington OH
401 PM EST Mon Dec 20 2021

INZ050-OHZ026-034-035-042>046-051>056-212115-
Wayne-Hardin-Mercer-Auglaize-Darke-Shelby-Logan-Union OH-Delaware-
Miami-Champaign-Clark-Madison-Franklin OH-Licking-
401 PM EST Mon Dec 20 2021

This Hazardous Weather Outlook is for East Central Indiana, Central
Ohio and West Central Ohio.

DAY ONE...Tonight.

Patchy fog will be possible overnight. There will be the potential
for some patchy dense fog in spots.

$$

Good morning all! Nice weather for December continues. A weak cold front passes thru tonight dropping highs into the 30s for Wed. We warm up on Thurs and of course Christmas time. Shower chances are looking higher esp for Christmas Day and into next week on some models. Not all agree for Christmas but next week, I think the chances pick up. Might see some frozen precip esp north next week but models again do not all agree on storm evolution, strength or track. We will continue to watch it as models are bouncing around a lot as well as the start of January which still holds some promise. Kind of a vague post this morning since the medium and long term forecasts are uncertain that's why.

MJO as of 12/19 per the Aussies has crossed over into Phase 7. Seeing a lot of guidance stalling it somewhere in 7 until early January. Thus, the Ensemble guidance and OP GFS's pushback again of the colder pattern. Stupid -PNA and stupid Nina...

Good Morning Les. Why has it been so mild and non winter-like so far this December. Several reasons and one is the uptick in La Nina and though the numbers will end up showing a weak La Nina when all is said and done it is still a moving target with ups and downs. Over the past 3 weeks or so La Nina has got somewhat stronger but not out of control so what else needed to happen as the atmosphere no doubt was acting like a much stronger episode. Yes we can look at the tellies with the positive AO and NAO and the negative PNA but those tellies happened because of what is going on in the world.

Each winter season we need to see if the events happening are somewhat normal for the season. Last year the record snows in northern Siberia at the end of November change the pattern but since that was a rare event models and forecasters had problems.

This season we need to look at the tropics. Usually in later August and September the tropics keep us usually in a somewhat stalled pattern and though models tend to cool us down quicker the reality is when the tropics are busy it just takes time for the pattern to head in the autumn season.

This brings me to December and two events in the tropics which are not the usual for this time of year and both in tropical areas. First the very strong typhoon in the southern Philippines. Sure that area is known for typhoons much of the year but in December to have one is rare but one that strong is very rare. Second the system that nobody seems to talk about was the adverse weather off the northeast coast of South America earlier this month. Very rare during December. So these two events of course puts more warmth further north than usual for the time of year. This in turn along with some very cold air that had already been established in Alaska and the western and central parts of Canada ended up providing the perfect outcome for severe weather in the central USA. We can also add the southwest ridge that has been going on for some time finally expanded eastward as the pacific northwest finally got into a stormier pattern which ended up forcing the ridge eastward. The southeast ridge which was nowhere to be found in November ended up being affected by the system of the South American coast which in turn boosted heights big time and this led to the southwest ridge along with the southeast ridge forming a huge ridge in the southern part of the USA. That is why you saw severe weather so much further north than usual.

So in the end the bully which will always be the tropics when it decides to misbehave won out this December. That is changing and the one good thing that we see is the cold in Alaska and much of Canada is primed to head southward and is just waiting for the green light. Unless the bully decides to strike again we will get into a much colder pattern. Models will be somewhat behind because it has seen all this warmth in the atmosphere at a time that is not usual for December.

That is my 2 cents worth and we know today that is worth only a penny.

Good morning Tim... Aussie MJO models show it now going into Phase 8 by mid Jan. GEFS and EPS both keep it stalled in Phase 7. If it stalls in Phase 7, we run mixing risks with frozen to rain or rain to frozen type events. Going to be tough to remain all snow without good timing and track of the shortwave energy. We really need Phase 8 to really get the -PNA to back off some. Canadian Ensemble still looks good in early January but the GEFS and EPS keep delaying the pattern change due to the MJO stalling in 7. Very uncertain. The cold is going to continue to dump into the West and we'll get glancing shots as pieces of it bleed east. This is not a cold and dry pattern upcoming at all. I see lots of storms to track and lots of up's and downs in temps. Going to be a lot of kitchen sink events in the next few weeks unless things change.

Doesn't this seem like the Groundhog Day movie? Models have a nice colder shift in the fantasy range only to pull the rug out from us and say, sorry suckas!!! Seems like we have been playing this tune for weeks now. LOL

Same temp this AM as yesterday in my hood....22 with a heavy frost.

cloudy72 wrote: ↑Tue Dec 21, 2021 8:15 am Doesn't this seem like the Groundhog Day movie? Models have a nice colder shift in the fantasy range only to pull the rug out from us and say, sorry suckas!!! Seems like we have been playing this tune for weeks now. LOL

Yep. Exactly Mike. Models continue to underestimate the influence of La Nina and a strong -PNA as well as the MJO not being where we need it. The -EPO and -NAO / -AO are nice but the EPO is not in the right position. Need it more into AK to kick the Western trough eastward some. Then we can start having much better chances for snow.

24 here w/ heavy frost. CVG got down to 26 I believe.

Nice post guys , all we can do now is wait for things to evolve, we sure do a lot of that in winter ,lol. Still give MJO a 50/50 chance of entering 8. Don't think it's a coincidence that the stubborn PAC ridge has loved taking a warm bath in the anomalis waters in the same region, and the positive tilt to it magnifies its crap position. How long will it last? Will it progress to the west coast? Will it retrograde back to that position most of winter? We need help....