Absolute Vorticity

tpweather wrote: ↑Fri Dec 16, 2022 11:45 am Les no matter what happens late next week you have mentioned the wind for several days and that is going to be an issue. The CMC would bring less snow but a worse outcome with a huge flash freeze.

Absolutely Tim! No matter how much snow falls, you can expect wind gusts in that 40 to 50 mph range. Visibility will be an issue for traveling and depending on how much we get, blowing and drifting snow is also going to be a problem. Whether or not the "B" word comes out depends on how intense this storm gets and if we can get a nice phase and that upper low to close off.

tron777 wrote: ↑Fri Dec 16, 2022 11:47 am

tpweather wrote: ↑Fri Dec 16, 2022 11:45 am Les no matter what happens late next week you have mentioned the wind for several days and that is going to be an issue. The CMC would bring less snow but a worse outcome with a huge flash freeze.

Absolutely Tim! No matter how much snow falls, you can expect wind gusts in that 40 to 50 mph range. Visibility will be an issue for traveling and depending on how much we get, blowing and drifting snow is also going to be a problem. Whether or not the "B" word comes out depends on how intense this storm gets and if we can get a nice phase and that upper low to close off.

Les I hope you have some time off next week because we are going to need you to stay over and work on the weather forecast.

tpweather wrote: ↑Fri Dec 16, 2022 11:49 am

tron777 wrote: ↑Fri Dec 16, 2022 11:47 am

tpweather wrote: ↑Fri Dec 16, 2022 11:45 am Les no matter what happens late next week you have mentioned the wind for several days and that is going to be an issue. The CMC would bring less snow but a worse outcome with a huge flash freeze.

Absolutely Tim! No matter how much snow falls, you can expect wind gusts in that 40 to 50 mph range. Visibility will be an issue for traveling and depending on how much we get, blowing and drifting snow is also going to be a problem. Whether or not the "B" word comes out depends on how intense this storm gets and if we can get a nice phase and that upper low to close off.

Les I hope you have some time off next week because we are going to need you to stay over and work on the weather forecast.

LOL! Working Mon thru Thurs and half a day on Friday. I am off the week between Christmas and New Year's per my norm. Hopefully, I'm not too busy with some of my customers taking an early vacation. (I hope)

Oh and one more thing.... I will worry about this later once we get a better handle on this system, but I also believe we need to keep that one eye open for the 12/26 thru 12/28 period as well. I'm also watching the signals for a system trying to get cooking. No idea yet if it's a little clipper or if any phasing with the STJ can occur? Again, worry about that later but you know me, I am always watching.

12Z GEFS precip type members valid for Thurs evening: Still quite a spread from a whimpy snow to a more wound up storm. Perfectly normal to see at this early stage of the game.

just got done clearing the drive. ended up with about 3" of very very wet snow/sleet. im glad its over and it was not too bad to drive around on. looks like we will be dry and chilly for the foreseeable future and then once we get into next week maybe we will have another storm to contend with, too early to tell right now.

airwolf76 wrote: ↑Fri Dec 16, 2022 12:02 pm just got done clearing the drive. ended up with about 3" of very very wet snow/sleet. im glad its over and it was not too bad to drive around on. looks like we will be dry and chilly for the foreseeable future and then once we get into next week maybe we will have another storm to contend with, too early to tell right now.

Glad you were able to get something out of the deal! Decent start to your season.

Already seeing big changes on the Euro at 108 hours (Tues evening). 0Z run had a 1009 MB low near Seattle and on the new 12Z run, it's still at 1009 MB but the northern stream is much faster with the low already located near the northern Idaho / Montana boarder. Then on the next panel (114 hours) the low is already down to 1003 MB. 0Z run had it at 1006 MB. Then at 120 hours, 998 MB low over Yellowstone. 0Z run was 999 MB NW of that location. So right now, it's a bit faster but also digging a bit more as well.

The Euro's probably going to be one of those crazy cutter like solutions again or have some kind of monster storm developing in future panels. It's similar in position now (comparing 0Z to 12Z) Denver, CO but the low is much, much stronger. 997 MB now vs 1003 MB on the 0Z run.

tron777 wrote: ↑Fri Dec 16, 2022 1:27 pm Already seeing big changes on the Euro at 108 hours (Tues evening). 0Z run had a 1009 MB low near Seattle and on the new 12Z run, it's still at 1009 MB but the northern stream is much faster with the low already located near the northern Idaho / Montana boarder. Then on the next panel (114 hours) the low is already down to 1003 MB. 0Z run had it at 1006 MB. Then at 120 hours, 998 MB low over Yellowstone. 0Z run was 999 MB NW of that location. So right now, it's a bit faster but also digging a bit more as well.

Such a huge difference in the Euro today. WHY??? There are many reasons as the ridging in the west a little steeper. I believe and this imo is one of the main reasons and Les we have talked about is spacing. I believe models got to fast with the main cold blast in here and everything just swept out to sea. I believe we are seeing the mother load of cold holding off for say 24-36 hours and this makes a difference.

Wow... look at this thing digging folks! At 150 hours, the 0Z run had a 1010 MB low over Iowa. Now on this new run, we've got a 1000 MB low in OK near the red river. A much improved Pacific look on this run with the PNA ridge in the spot where we want it along the West Coast. It's nice and tall as well allowing this thing to really dig. Let's see how this run shakes out. IMO we are seeing massive improvements here.

tpweather wrote: ↑Fri Dec 16, 2022 1:33 pm

tron777 wrote: ↑Fri Dec 16, 2022 1:27 pm Already seeing big changes on the Euro at 108 hours (Tues evening). 0Z run had a 1009 MB low near Seattle and on the new 12Z run, it's still at 1009 MB but the northern stream is much faster with the low already located near the northern Idaho / Montana boarder. Then on the next panel (114 hours) the low is already down to 1003 MB. 0Z run had it at 1006 MB. Then at 120 hours, 998 MB low over Yellowstone. 0Z run was 999 MB NW of that location. So right now, it's a bit faster but also digging a bit more as well.

Such a huge difference in the Euro today. WHY??? There are many reasons as the ridging in the west a little steeper. I believe and this imo is one of the main reasons and Les we have talked about is spacing. I believe models got to fast with the main cold blast in here and everything just swept out to sea. I believe we are seeing the mother load of cold holding off for say 24-36 hours and this makes a difference.

Yessir!!! It's a combination of the two. Exactly right. It starts with a better Pacific and that translate into better wave spacing so this thing can dig and get cooking!

The Euro at hour 168 is my new screen saver!!!

Temps spike up to 50 degrees Thurs evening ahead of the arctic front. We get rain maybe even some thunder then boom! Front passes, temps crash hard from 50 degrees at 7pm Thurs to 11 degrees at midnight. OMG!

tron777 wrote: ↑Fri Dec 16, 2022 1:38 pm Temps spike up to 50 degrees Thurs evening ahead of the arctic front. We get rain maybe even some thunder then boom! Front passes, temps crash hard from 50 degres at 7pm Thurs to 11 degrees at midnight. OMG!

Similar to the blizzard of 1978? If this were to happen and we are many days away but that is what you need to get a blizzard in these parts. That day we went from heavy rain until evening and then a hour of heavy sleet to heavy snow and by the next morning nobody was going anywhere. One thing to get a flash freeze which is never good but if the Euro pans out like this travel plans for the Christmas weekend will not be good at all.

Look at 500 MB Tim... The upper low closes off and slowly moves thru the OV on Friday with raging winds, very cold temps in the single digits and teens with snow falling as well! Wow!

Les this would be a dream storm and going to wait several days because we have seen such wild swings which I expected with an arctic air mass. I don't believe models have enough data to see these cross-polar outbreaks because they are rather rare.

Oh and if the Euro were to pan out like this,... LOW CHANCE as we all know but if it did... this system is so strong because it never does the energy transfer to the East Coast low. So we get the full force of this thing instead. Second, the QPF being shown on Friday is too low in my opinion as this thing is bringing in moisture from the Atlantic all the way into the OV as its so wrapped up! Still snowing Fri night finally giving way to snow showers as it finally wraps up Sat morning on Christmas Eve. Man oh man... I know. Not going to happen but what I wouldn't give to pay the snow gods off so that it would.

tpweather wrote: ↑Fri Dec 16, 2022 1:45 pm Les this would be a dream storm and going to wait several days because we have seen such wild swings which I expected with an arctic air mass. I don't believe models have enough data to see these cross-polar outbreaks because they are rather rare.

The ceiling is high on this one Tim potential wise. Anything from an arctic cold frontal passage with a band of snow producing 1-3" to an all out blizzard are still solutions that are on the table. Realistically, something like the GFS makes more sense given the pattern and that solution isn't too shabby either LOL

tron777 wrote: ↑Fri Dec 16, 2022 1:47 pm Oh and if the Euro were to pan out like this,... LOW CHANCE as we all know but if it did... this system is so strong because it never does the energy transfer to the East Coast low. So we get the full force of this thing instead. Second, the QPF being shown on Friday is too low in my opinion as this thing is bringing in moisture from the Atlantic all the way into the OV as its so wrapped up! Still snowing Fri night finally giving way to snow showers as it finally wraps up Sat morning on Christmas Eve. Man oh man... I know. Not going to happen but what I wouldn't give to pay the snow gods off so that it would.

Les those ratios would start off at 10-1 but ramp up quickly to 20 or 25-1. This thing almost is consider a bomb because of the pressure falls. Did you see the two big highs with one to the northeast and one to the northwest. Getting both that strong does not happen often.

tpweather wrote: ↑Fri Dec 16, 2022 1:50 pm

tron777 wrote: ↑Fri Dec 16, 2022 1:47 pm Oh and if the Euro were to pan out like this,... LOW CHANCE as we all know but if it did... this system is so strong because it never does the energy transfer to the East Coast low. So we get the full force of this thing instead. Second, the QPF being shown on Friday is too low in my opinion as this thing is bringing in moisture from the Atlantic all the way into the OV as its so wrapped up! Still snowing Fri night finally giving way to snow showers as it finally wraps up Sat morning on Christmas Eve. Man oh man... I know. Not going to happen but what I wouldn't give to pay the snow gods off so that it would.

Les those ratios would start off at 10-1 but ramp up quickly to 20 or 25-1. This thing almost is consider a bomb because of the pressure falls. Did you see the two big highs with one to the northeast and one to the northwest. Getting both that strong does not happen often.

I saw it! This run is just crazy! The upper low is at like 507 DM when it is over us! HOLY CRAP! I don't ever recall an upper low that deep over us before.

EDIT: My bad... 504 DM over Ohio is its max strength. Googly Moogly!

You guys had me at "a better ridge".

Les you know I am a pattern person and that is where I go first when trying to make a longer term forecast. Did I see this happening and no way possible and the reason why is because it seldom happens. Sure the pattern looked great for cold and yes a few bouts of snow but no way could I see this happening. Again we have many days ahead of us and was the info fed into the models correct today or was it yesterday. Such a correction by the Euro and Cmc today and when you get such a major change you must pay attention. Normally I would say this will not happen but this has a chance and that is because of the cross-polar air. We had this in the mid-late 70's a few times though we were in a weak El Nino stage of the game.

Bgoney wrote: ↑Fri Dec 16, 2022 1:57 pm You guys had me at "a better ridge".

GFS and Euro are def improving today with that PNA ridge. Hope to see that trend hold for sure.

tpweather wrote: ↑Fri Dec 16, 2022 2:02 pm Les you know I am a pattern person and that is where I go first when trying to make a longer term forecast. Did I see this happening and no way possible and the reason why is because it seldom happens. Sure the pattern looked great for cold and yes a few bouts of snow but no way could I see this happening. Again we have many days ahead of us and was the info fed into the models correct today or was it yesterday. Such a correction by the Euro and Cmc today and when you get such a major change you must pay attention. Normally I would say this will not happen but this has a chance and that is because of the cross-polar air. We had this in the mid-late 70's a few times though we were in a weak El Nino stage of the game.

That is 100% correct Tim but the extreme blocking in the EPO and NAO domains was also there in those classic mid to late 70s winters if you go back and find some archived 500 MB charts, That's why we are seeing such big time solutions from time to time. It doesn't mean they are right. But what it does mean is what can happen if all of the chips fall into place. That's basically it.