December 2023 Weather Discussion

[tron777]

Good evening folks! I think the forecast thru Christmas is pretty high confidence. We are quiet now, with a moderating trend starting tomorrow and lasting thru Christmas Day with the 50s. Rain looks possible on Friday then again Christmas Eve night into Christmas Day. We also look wet early next week as well. It is from the 28th onwards that things begin to get murky. We have a lot of different pieces of energy coming in thru the jet stream flow. Does any of it phase? Do we get a deepening upper low to create a rain to snow situation for us? This type of pattern looks to continue thru New Year's and possibly beyond. I still see no arctic air getting involved but we can get snow under the right conditions. It will be within the 3-4 day window that we will see it. Any model scenario showing snow behind 3 or 4 days likely isn't going to happen so keep that in mind when you are model watching. It's just the way it is. I wish I had better news but this is the reality for a while. We will basically see ridging across Canada with big upper level lows and STJ surface lows tracking underneath the ridging to our north. A lot of storm systems to track for sure so it won't be boring but storm evolution will be tough to detect from a long range perspective.

[MVWxObserver]

CVG / DAY both reached 36 and CMH 34 today.

[tron777]

Good morning all! Low to mid 20s across the area this morning. I don't have much to say as the ongoing forecast thru Christmas Day still looks good. Then from the 28th on, the models continue to wax and wane with their respective solutions. As BG says, it needs more time in the oven.

[tpweather]

Good morning all! Low to mid 20s across the area this morning. I don't have much to say as the ongoing forecast thru Christmas Day still looks good. Then from the 28th on, the models continue to wax and wane with their respective solutions. As BG says, it needs more time in the oven.

Good Morning Les and I agree about your forecast. Models will start to change as we head into next week. Again no arctic air at the moment but its not the worse case for getting winter weather with the upcoming pattern. Over the past few decades it seems January has been rather void of snow and ice. This upcoming January should break the pattern because of the strong STJ that should throw many systems across the south. This beats having a strong southeast ridge that gives us rain to light snow pattern imo. I do expect a couple bigger storms this winter and hopefully that is snow instead of ice. Still believe the mid-Alantic and northeast USA will be the winners but we should be close enough to get in on some of the action.

Looking to later next week and after the 28th like Les mentioned things are getting interesting from a pattern recognition and yes models will do their normal snow one day and nothing the next but with the upcoming pattern you will see a lot of last minute changes to the models as they try and time the STJ systems with upper systems that may be nearby. The one item that is always the wild card is the PV and will that weaken over the next few weeks and then where will the colder air head too.

[Bgoney]

Not sure if this has any effect, but reading Spaceweather.com, polar stratospheric clouds were seen in Sweden yesterday. They require temperatures below - 85C to form. A very early start.

An update from Spaceweather



Three days in a row PSCs have been sighted in Norway and Sweden.

Widely considered to be the most beautiful clouds on Earth, polar stratospheric clouds (PSCs) are rare. Earth's stratosphere is very dry and, normally, it has no clouds at all. PSCs form when the temperature in the Arctic stratosphere drops to a staggeringly-low -85 C. Then, and only then, can widely-spaced water molecules begin to coalesce into tiny ice crystals. High-altitude sunlight shining through the crystals creates intense iridescent colors that rival auroras.

During a typical Arctic winter, PSCs appear no more than a handful of times, and the first sightings usually come in January. This week's apparition marks an early start, and may herald many more PSCs to come.

[Bgoney]

The PV core has been displaced to that region along with those mind blowing temperatures(10hpa)

IMG_1074.jpeg

[tron777]

Hello folks... just a quick post on the longer term. The MJO per the Aussies as of 12/18 is on the border of Phase 7 and the Neutral circle. By now, it is probably on the border of Phase 8 and the neutral circle. Latest guidance still shows an emergence into phase 1 as we approach Christmas at a weak amplitude. From a Teleconnection standpoint, the PNA looks to be positive for the last week of Dec and into the New Year. The very +AO, looks to drop towards neutral, perhaps even weakly negative with the +NAO also dropping towards neutral by the New Year. So with all of this being said, I still have no changes to my overall longer term thoughts.

I still expect some light showers on Fri with the best chance for rain coming on Christmas Day. Rain may continue early next week until we see what happens with all of the upper lows / short waves running around the country. This could lead to a bigger storm system around the New Year's or early January time period. Again from around 12/28 on, I continue to have low confidence on what will happen until the model noise gets sorted out. A very mild Christmas with some rain is a lock. It is after that where we still have some questions to be answered.

[tron777]

I do like what I am seeing on all of the Ensemble Guidance though. If this is correct and not BS, they all finally develop a -EPO to allow for some cold air drainage to begin into Canada by the time 2023 ends and 2024 begins. An active STJ cuts underneath the ridging to our north. This is a nice look IMO for some fun and games esp in early January. We'll have to wait and see but the look being shown is good IMHO.

[tron777]

Here are the 0Z GEFS and EPS runs from overnight from around 12/27 thru the end of their respective runs. You can clearly see what I am talking about in the above posts.

GEFS 0Z.gif

EPS0Z.gif

[tpweather]

The PV core has been displaced to that region along with those mind blowing temperatures(10hpa)





IMG_1074.jpeg

Wonderful info Bgoney and I know very little about the correlation between temps in each layer. Only thing I have noticed this season is the temps in the arctic are not really that cold compared to normal on earth at the poles. Yes still seeing some -55 - -60 at times but nothing widespread at all. The place you show the coldest temps is where the coldest temps have been at lower latitudes this season. Mother Nature and trying to figure her out is never easy and when you finally believe you have somewhat of a grasp what she is doing she will throw a curve ball when your expecting a fast ball

[MVWxObserver]

CVG / DAY both reached 49 and CMH 45 today.

[tron777]

The PV core has been displaced to that region along with those mind blowing temperatures(10hpa)





IMG_1074.jpeg

Wonderful info Bgoney and I know very little about the correlation between temps in each layer. Only thing I have noticed this season is the temps in the arctic are not really that cold compared to normal on earth at the poles. Yes still seeing some -55 - -60 at times but nothing widespread at all. The place you show the coldest temps is where the coldest temps have been at lower latitudes this season. Mother Nature and trying to figure her out is never easy and when you finally believe you have somewhat of a grasp what she is doing she will throw a curve ball when your expecting a fast ball

The warming starts at the top (stratosphere) and you want to see it work its way down into the troposphere to get a SSW or a PV displacement, a PV split etc.

[tron777]

Evidence is certainly mounting for a major SSW in early January per the EPS and UKMET.

EPS.png

Dec-20-UKMO.png

[tpweather]

The PV core has been displaced to that region along with those mind blowing temperatures(10hpa)





IMG_1074.jpeg

Wonderful info Bgoney and I know very little about the correlation between temps in each layer. Only thing I have noticed this season is the temps in the arctic are not really that cold compared to normal on earth at the poles. Yes still seeing some -55 - -60 at times but nothing widespread at all. The place you show the coldest temps is where the coldest temps have been at lower latitudes this season. Mother Nature and trying to figure her out is never easy and when you finally believe you have somewhat of a grasp what she is doing she will throw a curve ball when your expecting a fast ball

The warming starts at the top (stratosphere) and you want to see it work its way down into the troposphere to get a SSW or a PV displacement, a PV split etc.

Thanks Les and I do understand that but I guess is when you see those kind of temps in the stratosphere then Mother Nature will balance it out elsewhere. Sometimes we just think of mother nature on the ground but I believe in really is much much wider including the sun

[tpweather]

Good Evening and again models are going to have problems for a few more days. We always look to the northwest for the most part to get a colder pattern. Well that is a problem when that area is not so cold and little in the way of snow. Then we look northeast and eastern Canada has done well with snow even after the brief warmer spell the past few days. Like we have talked about most of this season is the east coast should really do well and it makes sense to find a place where the cold can travel without using up to much of the cold because of bare ground. Watch for these troughs to first dig east of us and migrate westward and hopefully hook up with energy from the STJ. Still a good pattern to get some decent storms with an active STJ and I believe there will be enough cold at times to help us with a decent winter

[tron777]

The PV core has been displaced to that region along with those mind blowing temperatures(10hpa)





IMG_1074.jpeg

Wonderful info Bgoney and I know very little about the correlation between temps in each layer. Only thing I have noticed this season is the temps in the arctic are not really that cold compared to normal on earth at the poles. Yes still seeing some -55 - -60 at times but nothing widespread at all. The place you show the coldest temps is where the coldest temps have been at lower latitudes this season. Mother Nature and trying to figure her out is never easy and when you finally believe you have somewhat of a grasp what she is doing she will throw a curve ball when your expecting a fast ball

The warming starts at the top (stratosphere) and you want to see it work its way down into the troposphere to get a SSW or a PV displacement, a PV split etc.

Thanks Les and I do understand that but I guess is when you see those kind of temps in the stratosphere then Mother Nature will balance it out elsewhere. Sometimes we just think of mother nature on the ground but I believe in really is much much wider including the sun

Exactly Tim. It is a top to bottom approach for sure. From the sun, to the stratosphere to the troposphere (where our weather occurs) to the surface where we live. It all matters in weather.

[tron777]

Good morning all! Fri night into early Sat is our first shot of light rain. We may hit 60 on Christmas Eve! Then, it continues to look to like a muddy Christmas Day this year with rain and mild temps. Rain early next week also then after that... the model chaos continues. I do think we see a slow transition to a cooler pattern but storm evolution, timing, and precip type are still in question in my mind.

[Bgoney]

Almost 3weeks in the books and temp wise around 4+ mean temp , below normal Qpf , CVG and most of OV. Pattern persisted, lack of strong lows for the middle of country and no SE ridging equals limited GOM flow into much of central US . That looks to continue with the Christmas rain event

IMG_1086.png

IMG_1085.png

[tron777]

I agree with the above. I am thinking 1/2" or less for rainfall with the Christmas Day / 26th rain event.

[Bgoney]

More musings, expected warm temps for Xmas/eve should have no problem making top ten

IMG_1088.jpeg

IMG_1089.jpeg

[tpweather]

Good Morning and another nice day for shoppers. First day of winter so 90 days or so until spring. So far this fall season we have seen the coldest compared to normal over eastern Europe then it switched for a short time to western Europe and current cold is in eastern Asia over China. When these cold spells come they are really cold and one reason is because its so warm on our side of the planet. Some places in the upper mid-west and northern plains will probably end up 15 degrees or more above normal for December. Once again Mother Nature doing her balancing job. The good thing imo is the cold is not staying in one place for an extended period and will this continue around the globe and hit us in January. This is not counting on the SSW event if it were to occur.

What is funny is when you get a stronger El Nino much of China is usually very mild and it started that way early in the fall with record temps but it has switched and done a 180. The STJ and we talk about it quite often but the jet does not stop and heads around the world and so far with it being well south this has helped both Europe and Asia to get cold and stormy. Hopefully the STJ gets into its normal position during and El Nino and this hopefully will bring more storminess but having systems getting closer to together to merge and that is so important. That happened this past weekend and the only problem is we still had too much warm air around but the storm was able to bring a quick shot of cold to the east.

[tron777]

Bgoney... no doubt! I expect 60 on Christmas Eve and probably a touch cooler, U50s on Christmas Day due to the rain.

Tim... This Nino is still acting like a Nina IMO. Another example is typically Australia is dry during a Nino and wet during a Nina. They have been very wet in December.

[Bgoney]

One more record that will be broken , unless we have an unforeseen development. Our coldest temp of 2023 calendar year is 15 degrees, that would smash the current # 1 for a calendar year

IMG_1061.jpeg

[tron777]

One more record that will be broken , unless we have an unforeseen development. Our coldest temp of 2023 calendar year is 15 degrees, that would smash the current # 1 for a calendar year

Wow! That stat is truly incredible! It's pretty sad actually that we can't even get colder then the teens.

[Bgoney]

One more record that will be broken , unless we have an unforeseen development. Our coldest temp of 2023 calendar year is 15 degrees, that would smash the current # 1 for a calendar year

Wow! That stat is truly incredible! It's pretty sad actually that we can't even get colder then the teens.

Yes it is, You can see how it extremely difficult to even come close to double digits let alone the mid teens