December 2024 Weather Discussion

[Bgoney]

What would be the difference from the map posted above by Bgoney and this map from the NOAA? Just trying to figure this out.

Great question, and really no reason I posted one over the other as they prove my point. One is a yearly comparison to normal while the other is compared to the historical average over many years. Here’s what AI has to say


When discussing Sea Surface Temperature (SST), "global mean" refers to the average temperature of the ocean surface across the entire globe, while "anomalies" represent the deviation of the SST at a specific location from its long-term average for that location and time of year, essentially showing how much warmer or cooler the current temperature is compared to the "normal" value; meaning, anomalies focus on local variations from the global average, not the global average itself.
Key points to remember:
Global Mean SST:
This is a single value representing the average temperature of the ocean surface across the entire planet.
SST Anomaly:
This is the difference between the current SST at a specific location and the long-term average SST for that location at that time of year

[Bgoney]

A day late but worth remembering

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[Bgoney]

Gotta like all that potential the models keep flashing for the pre-Christmas period. We have a bit of a history for this time period.

[tron777]

Gotta like all that potential the models keep flashing for the pre-Christmas period. We have a bit of history for this time period.

The players are there on the field.... an active polar and STJ, and a nice chunk of arctic air dropping in. We don't have a -NAO but other then that, everything else is looking interesting!

[tron777]

27 as of 1pm at CVG. It looks like we should be able to stay below freezing for the high. Clouds from that little I-70 disturbance should make sure of that.

[dce]

What would be the difference from the map posted above by Bgoney and this map from the NOAA? Just trying to figure this out.

Great question, and really no reason I posted one over the other as they prove my point. One is a yearly comparison to normal while the other is compared to the historical average over many years. Here’s what AI has to say


When discussing Sea Surface Temperature (SST), "global mean" refers to the average temperature of the ocean surface across the entire globe, while "anomalies" represent the deviation of the SST at a specific location from its long-term average for that location and time of year, essentially showing how much warmer or cooler the current temperature is compared to the "normal" value; meaning, anomalies focus on local variations from the global average, not the global average itself.
Key points to remember:
Global Mean SST:
This is a single value representing the average temperature of the ocean surface across the entire planet.
SST Anomaly:
This is the difference between the current SST at a specific location and the long-term average SST for that location at that time of year

Thank you Bgoney. That is a really good explanation. We can see that the oceans as a whole, particularly the Pacific, has cooled substantially.

[dce]

This is for a La Nina phase 6 in the month of December. I wonder if because we are pretty close to seeing very very weak La Nina conditions if this isn't actually in play. The medium range model runs are starting to show something pretty similar to this in my opinion.

[snowbo]

Light snow here. Pavements dusted, at least the ones that didn't have a ton of salt residue on them.

[tron777]

This is for a La Nina phase 6 in the month of December. I wonder if because we are pretty close to seeing very very weak La Nina conditions if this isn't actually in play. The medium range model runs are starting to show something pretty similar to this in my opinion.

I agree Doug, You have a nice PNA ridge with arctic air getting involved, but no -NAO and that is pretty much what it's looking like as we head towards Christmas. That is an ?El Nino look so ENSO clearly is not driving the pattern at this time (La Nina). It is MJO driven to some extent for sure.

EDIT: Let me add... Look at the ridging over Europe and Asia. The coldest air is on our side of the globe as we kick off the winter season. You can't ask for more to be honest. This December, while not a ton of snow, has been colder then avg and as a season, we are running above avg in snow (using CVG). I'm pretty happy with how things have started.

[tron777]

Light snow here. Pavements dusted, at least the ones that didn't have a ton of salt residue on them.

Awesome! That band extends all the way back into Central ILL. It will weaken with eastward extent, but an inch on the grass / car tops I think is doable for you! Good luck!

[MVWxObserver]

A day late but worth remembering



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If I remember correctly, one of the touchdowns was in Moscow, OH e.g. that was supposed to be a nuclear power plant location, but thankfully instead, a converted coal-powered one.

[MVWxObserver]

Pretty out there this evening as the streets and driveways e.g. etc. are covered in my 'hood.

Currently 18 here in G'ville and progged for around 16 on Fri morning.

[MVWxObserver]

CVG reached 31, DAY 25 and CMH 26 today.

[tron777]

There should be a good snow to liquid ratio too since temps are that cold.

[tron777]

Good morning all! I don't have a lot to say this morning since nothing has really changed. We still warm up and get wet by Sat evening thru the day on Sunday. Then another round early next week. 1-2" of rain looks to fall from now thru Tues of next week. Once we get past that, we cool down towards the end of next week and remain cold leading up to Christmas. The players are still on the field and we are still waiting to see if anything can phase for a bigger system or are we in clipper land.

[Bgoney]

Still dry and lacking snow for much of the plains

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[Bgoney]

The well advertised mid month warm up arriving on schedule. Still a progressive pattern of warm and cold periods through Christmas.

[tpweather]

Good morning and had to take a few days off for personal reasons but some great posts. At least this December has been busy and looks like its going to get busier. My son up Wisconsin has been below zero since Wednesday night with some wind chills at -30 and that is quite impressive especially after they changed how wind chills were calculated.

Another dose of rainfall later Saturday into Sunday as we continue to pull out of the drought. Will take a look at the models since I have been gone for a few days but from the posts I see on here a rather progressive pattern and like Les mentioned the NAO is the one item that we need to slow the process down but with the AO negative for the most part and the Pna positive we are not going to blow torch though you can still get a day or two ahead of a nice front to see temps in the 50's but no week long period of 50's.

[tron777]

Glad to see you back Tim. The bottom line is mild and wet followed by cold and ??? The question is cold and dry or cold and some wintry action? These are the two big weather stories for us from now thru Christmas.

[tpweather]

Glad to see you back Tim. The bottom line is mild and wet followed by cold and ??? The question is cold and dry or cold and some wintry action? These are the two big weather stories for us from now thru Christmas.

Thanks Les and this has been the most excited I have been for several winters. Could it turn out to be a dud and sure anything is possible but most signs look really good over the next 45 days or so. I do want to see more snow in the northern and central plains as this is a key in getting cold outbreaks further south and also having them stay around for a period of time. Still not halfway through December so we are okay and all it takes is for 1 or 2 big storms to help in that matter. The PV has been sort of wild this year as it seems to want to stay weak and stretch its legs out every week or so and this keeps temps rather cold in some lower latitudes. Early this week I saw a -50 - -60 reading in Siberia but at the moment -46 so its not like the PV is getting stronger and I though it might when I saw those temps below -50. Even -50 in that part of the world is nothing to write home about because most years they will have a period or two of -60 and lower and when that happens the pv is usually strong. Just thinking out loud and Les you always mentioned how the pacific rules the roost and you are correct but with a back to normal typhoon season in the eastern Pacific did this finally help us get back to at least a normal winter. I agree about the call on La Nina and whether its a weak one or just neutral Enso they outcome seems similar. We tend to get better winters with a weak La Nina,weak El Nino or neutral Enso. Strong ones usually brings us to much warm weather and we see many days above normal and chances for snow not so good. Good thing is we are almost twice the norm for snowfall this season and hopefully that trend continues.

[tron777]

We are definitely starting off this winter much different then the last several. It's the coldest start to December IMO since 2010. We could always use more on the snow side but I'm not complaining since we're actually 1.9" above normal going into today. Lots more fun and excitement to come over the next 2-3 months.

[Bgoney]

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[Bgoney]

The PV I agree hasn’t been overwhelming but that’s been because a lack of coupling between the strat and trop, but latest few model runs are showing a coupling so this needs to be watched. We definitely don’t want that to happen

[tron777]

Let's hope a recurve into Phase 6 is wrong. As long as it keeps moving and gets into 7 we're good. Definitely a lot of uncertainty in the longer term. We do look to have a +PNA, -EPO and -AO but the NAO remains positive so not sure how that will factor in going forward. As usual, we wait and see. One thing that we know of is that it is active and shots of cold air continue to dive in but the overall pattern is progressive thanks to the NAO being positive.

[Bgoney]

Let's hope a recurve into Phase 6 is wrong. As long as it keeps moving and gets into 7 we're good. Definitely a lot of uncertainty in the longer term. We do look to have a +PNA, -EPO and -AO but the NAO remains positive so not sure how that will factor in going forward. As usual, we wait and see. One thing that we know of is that it is active and shots of cold air continue to dive in but the overall pattern is progressive thanks to the NAO being positive.

GFS as expected is already backing off the amplitude it had from yesterday going forward