Absolute Vorticity

tpweather wrote: ↑Mon Jan 13, 2025 12:17 pm

tron777 wrote: ↑Mon Jan 13, 2025 12:06 pm I agree Tim on throwing the OP GFS out. Any model that shows a snow storm in Florida should automatically be tossed. CMC as you said Tim is still a little too far south for us this coming Sunday into next week, but it is certainly a more realistic solution. Again, it is a wait and see game but we will need to see how much of a bully the cold air is behind the rain we get for this coming Fri into Sat morning. Once we get that figured out, then we should see where the front stalls with regards to that secondary follow up wave. GEFS low pressure tracks range from an Apps runner into West Virginia to a slider thru the SE US. None of them give FL a snow storm so we know that's BS to begin with.

Les one of the main items I will be watching is the strong high out west. The CMC has this further west than the GFS which in turn allows a better flow from the GOM next week. If that high is further east no doubt this hurts are chances for a decent system. If the high is further west then I believe chances go up. Again just looking at the pattern and really not a specific storm.

Wonderful post Tim! Like we saw with the last couple of snow makers, the PNA ridge out West was in a perfect spot for us (along or just off the Coast). On the GFS, the ridge axis is too far away from the Coast but gets better around 1/21 onwards. The 12Z Canadian is even further west then the GFS as you mentioned, but it also looks better by early to mid next week. Interesting times ahead as usual. I also think past Euro runs have been overdoing the cold too. Until that issue is resolved, I'd be tossing out some of those runs too.

Les I agree about the Euro being too cold on the runs. Sure its a nice arctic air mass coming this way but how cold and how far south will that cold extend. Like I have mentioned the polar regions have been above normal all season and sure still get plenty of cold but -50 starting out compared to -70 that you see many years is a big difference. I am banking on that somewhat and believe though cold not what the Euro is seeing at this time.

tpweather wrote: ↑Mon Jan 13, 2025 1:12 pm Les I agree about the Euro being too cold on the runs. Sure its a nice arctic air mass coming this way but how cold and how far south will that cold extend. Like I have mentioned the polar regions have been above normal all season and sure still get plenty of cold but -50 starting out compared to -70 that you see many years is a big difference. I am banking on that somewhat and believe though cold not what the Euro is seeing at this time.

All models have honestly been overdoing the cold all winter long. We'll see if that model bias continues. It probably will.

tron777 wrote: ↑Mon Jan 13, 2025 1:18 pm

tpweather wrote: ↑Mon Jan 13, 2025 1:12 pm Les I agree about the Euro being too cold on the runs. Sure its a nice arctic air mass coming this way but how cold and how far south will that cold extend. Like I have mentioned the polar regions have been above normal all season and sure still get plenty of cold but -50 starting out compared to -70 that you see many years is a big difference. I am banking on that somewhat and believe though cold not what the Euro is seeing at this time.

All models have honestly been overdoing the cold all winter long. We'll see if that model bias continues. It probably will.

I believe part of the problem is the lack of or very little snow in the northern plains and upper mid-west. Another problem has been especially for nighttime lows is the lack of a clear sky and/or no wind. Wednesday morning will be interesting to see how cold we get with the correct conditions. If we see no wind and a clear sky 0 - -5 should work out fine but if the temps stay well into the upper single digits with the same conditions then no doubt models are too high with temps and some forecasters like myself

tpweather wrote: ↑Mon Jan 13, 2025 1:23 pm

tron777 wrote: ↑Mon Jan 13, 2025 1:18 pm

tpweather wrote: ↑Mon Jan 13, 2025 1:12 pm Les I agree about the Euro being too cold on the runs. Sure its a nice arctic air mass coming this way but how cold and how far south will that cold extend. Like I have mentioned the polar regions have been above normal all season and sure still get plenty of cold but -50 starting out compared to -70 that you see many years is a big difference. I am banking on that somewhat and believe though cold not what the Euro is seeing at this time.

All models have honestly been overdoing the cold all winter long. We'll see if that model bias continues. It probably will.

I believe part of the problem is the lack of or very little snow in the northern plains and upper mid-west. Another problem has been especially for nighttime lows is the lack of a clear sky and/or no wind. Wednesday morning will be interesting to see how cold we get with the correct conditions. If we see no wind and a clear sky 0 - -5 should work out fine but if the temps stay well into the upper single digits with the same conditions then no doubt models are too high with temps and some forecasters like myself

In addition, they have been performing terribly with sky cover too. Guidance has been too cold at night and it's been tough for us to shake the clouds to have good raditional cooling.

SPS from the boys for tonight (cold temps).

...COLD CONDITIONS TONIGHT INTO TUESDAY MORNING...

Wind chill values will dip to near, or slightly below, zero
tonight into Tuesday morning.

Dress in layers including a hat, face mask, and gloves if you must
go outside. Keep pets indoors as much as possible.

Don't forget about our little light snow event tomorrow afternoon. Not everyone will see it, but a few locations could get up to 1". The further north from Cincy the better the chance IMO.

How strongly negative has the EPO been? How strong is the ridging over Alaska? Why has this been such a stable pattern? This graphic might help explain one of the factors.

Both CVG / CMH got to 36 and DAY 33 in the predawn today.

Good Evening and ready for some cold weather once again and a little snow as well. Nice to see that in Alaska Les and no doubt that tends to happen when we stay cold for a longer period of time. What will next week look like and something you start to watch is the tellies and the last few days the NAO looked like it was going really positive and this does not help in blocking that can help build some nicer storms. Today not so positive and watch this over the next several days and the AO which looked to go really positive is still expected to but not what the models showed a few days ago.

This tells me the pattern is shaping up and the tellies are starting to see this and expect more changes as the week wears on. Next week looks stormy and we just need to find out when and where and yes over the next few days you will see a big snowstorm in our area one day and the next cold and dry. This is true especially with the gfs that goes back and forth like a see-saw during the winter. I do believe the CMC and Euro is seeing the pattern but they just need to narrow down dates for storms. Yes cold will be available and hopefully we can keep some at bay because if we get the full surge then yes cold and dry is possible but I don't believe we see the full surge.

MJO is on the border of 8 and 1 and a very nice phase which should be at least a couple of weeks before we see any major pattern change to warmer weather.

Good morning! 9 at CVG right now, 7 here. We await our shot at some light snow later today then cold. We warm up, get wet, then can we get a little snow with that secondary low Sun into Sun night? Cold for MLK Day and a good chunk of next week. Snow chances TBD.

GFS says Nope and continues to suppress everything. Euro skims us on Sunday with the CMC still being the most aggressive for early next week.

Happy Birthday Eric! I hope you have a wonderful day Bro!

6Z GFS definitely took a big leap towards the Canadian's solution for next week. We have a long way to go but it's worth watching. With the front coming thru on Sat (rain ending as flakes) is going to be step #1 with regards to getting this system nailed down. We want to see the front stall over the TN Valley / S Apps area. Then, we either get that follow up wave Sunday or a bigger system for next week as the CMC and now 6Z GFS are trying to hint at. My forecast confidence thru Saturday is high. Beyond that, extremely low.

Low was 4 earlier here

Happy Birthday Eric!!! Hope you have a wonderful day and no outdoor bocce ball today.

Good Morning and a nice chill this morning and can we see below zero Wednesday morning. As we know if conditions are good then should be no problem and we may not make it to 20 in the afternoon on Wednesday. Looks like some rain later Friday until about mid-day Saturday. Can that end as snow and sure with arctic air coming in behind but usually this would just be some kind of dusting to 1 inch at best. Then we let the arctic front decide where it wants to set up shop. Still believe the CMC is understanding the pattern and the latest fun of the GFS has at least developed a system though pretty far south I believe that for at least this run it seems to have corrected itself. The Euro which I really thought would come around towards the CMC still shows no storm and just pure cold. Again we have several days to watch this unfold. I still believe a second storm for MLK day or Tuesday but exactly the placement is first getting the players all together then figure out more details.

Official overnight lows:

HAO: -2
CVG: 8
MGY: 5
CMH: 7
DAY: 6

tpweather wrote: ↑Tue Jan 14, 2025 7:37 am Good Morning and a nice chill this morning and can we see below zero Wednesday morning. As we know if conditions are good then should be no problem and we may not make it to 20 in the afternoon on Wednesday. Looks like some rain later Friday until about mid-day Saturday. Can that end as snow and sure with arctic air coming in behind but usually this would just be some kind of dusting to 1 inch at best. Then we let the arctic front decide where it wants to set up shop. Still believe the CMC is understanding the pattern and the latest fun of the GFS has at least developed a system though pretty far south I believe that for at least this run it seems to have corrected itself. The Euro which I really thought would come around towards the CMC still shows no storm and just pure cold. Again we have several days to watch this unfold. I still believe a second storm for MLK day or Tuesday but exactly the placement is first getting the players all together then figure out more details.

Lots of uncertainty for sure Tim with regards to Sunday Jan 19-22nd time frame. One system, two systems or is it a swing and a miss? We'll just have to wait and see.

Ensembles keep things suppressed atm . Pattern most favorable for the Southern Apps /SE states

Good Morning Les and you are correct and sometimes with true arctic fronts you can get these little pieces of energy to ride along the front because of the wide difference in temps on either side of the front. High pressure and the CMC keeps the high strongest well to the west which no doubt helps in bringing up a bigger storm. The gfs on the other hand sort of splits the High into 2 distinct pieces and one out west but not quite as strong as the CMC but still strong and another piece of the High that comes in with the arctic front but moves further to the east and does allow a storm to form. The Euro really wants to have the high go straight to the gulf coast and again we know this would shut of any return moisture from the GOM.

The pattern is there for a bigger storm and that is all we can ask for this far in advance. Sometimes you miss out even with a good pattern but so far this season we have been doing okay and lets hope this continues for at least another 2 weeks or so.

Everyone's thoughts at the moment have a good chance to verify. We'll have to wait a few more days until these clippers move thru so we can focus in on where the arctic front stalls on Saturday / Sunday time frame.

One other item and this is really for Friday before the rain moves in later in the day. I expect quite a bit of fog with the surge or warmer air over top of the snow cover. This surge of course would be much warmer if not for the snow cover but still have a chance to get near 50.

tron777 wrote: ↑Tue Jan 14, 2025 4:34 am Happy Birthday Eric! I hope you have a wonderful day Bro!

Happy birthday Eric!

tron777 wrote: ↑Tue Jan 14, 2025 7:56 am Everyone's thoughts at the moment have a good chance to verify. We'll have to wait a few more days until these clippers move thru so we can focus in on where the arctic front stalls on Saturday / Sunday time frame.

I agree Les and its really a 3 way split at this moment and odds imo would be about 33p/c chance for each one to be correct per the models though I am in the camp of 40p/c each for the GFS and CMC and 20p/c for the Euro. Still not a ton of snow in the northern plains and upper mid-west plus some melting in the central plains,tn valley and ohio valley late in the week. Cold loves snow packs and if we had a deeper one further north then better shot with the Euro. This is going to be the strongest arctic cold this season though with temps only starting out in the -40 -50 range instead of -70 or colder its not the coldest arctic outbreak ever and yes it can make a difference. Will watch the NAO big time later this week and again yesterday it made a move to less of a positive side though still going positive but if this treads more towards neutral in the next few days then slowly down of the arctic front is more likely. If it goes the opposite and gets a more positive sign then chances will go down for a bigger storm but still can have smaller systems near the front itself. As always a puzzle and sometimes 10 piece which is very simple and some 1000 piece which makes my head hurt but at the moment will go with one that has 100 pieces and see will start working on the edges later this week