Absolute Vorticity

tron777 wrote: ↑Thu Nov 17, 2022 8:22 am Good morning all and I have some thoughts put together. Fri morning looks interesting for some folks to get a quick 1/2" of snow. Id say anytime from about 4am thru about 8am is prime time with just flurries after that on and of for the remainder of the day. But with this next surge of cold air, a weak disturbance is going to be along the front coming in along with it to produce the lift needed for accumulating snow. Models differ on where this band moves thru. I-70? CVG Land? Somewhere in between? Whatever location gets hit, look for a quick hitting 1/2" of snow tomorrow morning which may cause a few issues with temps plenty cold enough in the 20s. Expecting Low 30s with flurries only in the afternoon. Then a cold and dry weekend.

Then we warm up some before Thanksgiving. Speaking of that system, what a miss the overnight models are! Big time struggling as I thought would happened due to the -NAO. We may see a more northern dominated system after all almost like a clipper system. Or the southern system rides further south if we do see the STJ disturbance. LOW confidence now from Thanksgiving on for me. Going to have to slow down a bit and take a closer look at it as time goes on.

Great post and anytime you see the NAO go negative even for a short amount of time models have trouble with incoming systems. I am just leaving my forecast the same until I see anything major that would throw the forecast off. Yes I believe there will be some slick spots and with the arctic air you don't need a lot of precip to put down a quick 1/2 inch. Road temps should be below 32 for everyone and like Bgoney mentioned this morning already saw some slick spots on elevated roadways and bridges.

What a wonderful video by DT. I believe he is one of the best for long term forecasting and he just misses the short term quote often but hard to be perfect at all areas. Les he talked a lot about the NAO which you have mentioned several times. He is leaning towards the NAO being negative and maybe strongly negative in early Dec. Do I believe that is going to happen and yes but a different time period. I am leaning towards the mid-Dec period and my main reason is I am expecting a positive AO later in November and early December. He mentioned the winds with the PV and how last year they were strong which of course gave us such a mild December. He showed the winds not nearly as strong this season and of course disrupting the PV is much easier. Again I believe that will happen this season but my timeline is just a few weeks later.

So its nice that a met like DT is seeing a similar pattern but we are just off in timing. So who is correct and no ideal and both may be wrong but the pattern looks great for winter weather in December however whose timing is going to be correct. I know Les you have been waiting for more info because you see it both ways though I believe you are more inline with DT than myself and hopefully I am reading that from your posts and not putting words in your mouth.

Another item he mentioned and we have on here is how cold this outbreak is with very little snow cover to the north and west of us. Again once we warm up next week we don't have to melt snow so warming can happen a little quicker than normal. Also he pointed out that both the Euro and Gfs have a storm next week and I agree 100p/c. The Euro is stronger and warmer than the GFS and I am still going more towards the gfs at this moment but he does mention the cold coming in behind for next weekend and also chances for some snow at the end of the storm. He them believes cold will continue into early Dec and that is where DT and myself differ. He has been doing this along time and I believe a great long-term forecaster so when I see that I start going over and over what I see. At this point still going with my thoughts but I may be crazy but not stupid to start looking at some of the items he threw out.

That Thanksgiving and holiday weekend system atm has a lot going on. If you take blends from GFS/EU , you run the gamut. MillerA, MillerB, or a cutter , achance for each. No way to know 7-8 days out of course with timing of shortwaves and where the highs are situated. But like was mentioned, at least its not boring

The next surge of cold air is in eastern Iowa at the moment with a band of light snow. Again not a ton of precip but higher ratio's can give someone a quick 1/2 inch as it moves through late this evening and overnight.

Bgoney wrote: ↑Thu Nov 17, 2022 10:11 am That Thanksgiving and holiday weekend system atm has a lot going on. If you take blends from GFS/EU , you run the gamut. MillerA, MillerB, or a cutter , achance for each. No way to know 7-8 days out of course with timing of shortwaves and where the highs are situated. But like was mentioned, at least its not boring

I agree Bgoney and I am more a Miller lite guy myself

Gents.... It'll be interesting to watch and if the -NAO is real we can back off a bit on the milder talk. Should the MJO get towards 8 in December as DT talked about then WOOF indeed. Anyway, I will worry about the longer term later, I am def more interested in the Thanksgiving Holiday time period at this point. This system is probably going to need to take center stage right now.

And Tim... we are on the same page for tomorrow AM with that 1/2" potential. If CVG cashes in our 2" call for the entire week was money!

Nice video by Brian this morning. He did mention about how the models wanted to clear us out later today and models do a horrible job in the Ohio Valley during the cold weather season as most of the time stick with clouds over clearing. Once we get a stronger shot of cold air this weekend I expect more sunshine. I always put in more clouds and lower high temps during the winter around here unless its truly a strong arctic blast then we tend to move the clouds out more but of course the air is colder but drier. I believe he is like us in trying to figure out next week and we are seeing battles going on between the northern and southern stream and which one is stronger or do they have a date. I believe though colder air will come back in after the system for a few days and the models do agree on that outcome.

tpweather wrote: ↑Thu Nov 17, 2022 10:44 am Nice video by Brian this morning. He did mention about how the models wanted to clear us out later today and models do a horrible job in the Ohio Valley during the cold weather season as most of the time stick with clouds over clearing. Once we get a stronger shot of cold air this weekend I expect more sunshine. I always put in more clouds and lower high temps during the winter around here unless its truly a strong arctic blast then we tend to move the clouds out more but of course the air is colder but drier. I believe he is like us in trying to figure out next week and we are seeing battles going on between the northern and southern stream and which one is stronger or do they have a date. I believe though colder air will come back in after the system for a few days and the models do agree on that outcome.

I'd be shocked if we saw any sunshine at all today. If we see a peak or two that would be it and not enough to raise pavement temps. IMO (and BG felt the same way) then if that 1/2" comes over us, it'll get slick. No doubt in my mind. It's the location of the best snows that we are waiting to see occur.

Think the mods are overdoing the speed of MJO again, Much like its last go round through the pac. Nothing has changed in the 6 -7phase region since then, at present anomalis easterlies are beastly , brick wall of cold water well west of dateline, so I'd be surprise if it didn't spin its wheels a bit for a time somewhere in the 6-7 region

will be watching some live streams on the Buffalo Blizzard. some areas got over 15 inches already

Clouds are doing a number on temps. 31 CVG, 30 here attm. 12Z GFS continues to look cooler and more wintry and less in the way of mild weather and heavy rain. Big snow storm Fri / Sat for folks just East of the OV. Looks like the northern stream cuts off over us then transfers its energy to an East Coast low for the big event in the interior Northeast. A very plausible solution with the -NAO in place. Look for more changes such as that in the days to come.

Bgoney wrote: ↑Thu Nov 17, 2022 11:31 am Think the mods are overdoing the speed of MJO again, Much like its last go round through the pac. Nothing has changed in the 6 -7phase region since then, at present anomalis easterlies are beastly , brick wall of cold water well west of dateline, so I'd be surprise if it didn't spin its wheels a bit for a time somewhere in the 6-7 region

Bgoney, this has also been part of my milder period the first two weeks of Dec. I agree about the speed of the mjo and models that forecast the mjo has this problem quite often. That along with imo is a positive AO the first two weeks of Dec will keep the cold at bay. I know once again I seem to be on that tiny island by myself and this happens several times each winter but I can only forecast what I see and not what I hear.

I came in this afternoon to look at the afternoon models and again much different than yesterday. Why the run to run changes and there must be a reason but I have no ideal what that reason is. Les has talked about the NAO and yes that could be a reason or during most La Nina's the northern jet becomes the boss and she is taking over. I am still leaving my forecast the same with system Thanksgiving day in the form of rain switching to some snow and cold next weekend followed by a nice warm up. When the models change run to run I believe its best to stick to what you believe has the best shot of happening. Does not mean it will but I seldom change my forecast because of the models as I just use them as a resource and at the moment that resource is not helping lol.

tpweather wrote: ↑Thu Nov 17, 2022 1:56 pm I came in this afternoon to look at the afternoon models and again much different than yesterday. Why the run to run changes and there must be a reason but I have no ideal what that reason is. Les has talked about the NAO and yes that could be a reason or during most La Nina's the northern jet becomes the boss and she is taking over. I am still leaving my forecast the same with system Thanksgiving day in the form of rain switching to some snow and cold next weekend followed by a nice warm up. When the models change run to run I believe its best to stick to what you believe has the best shot of happening. Does not mean it will but I seldom change my forecast because of the models as I just use them as a resource and at the moment that resource is not helping lol.

Just wanted to add as I looked at the forecast for eastern Siberia once again and another 180 turn. One day temps expected to be -75 and the next day maybe -40. Sure you this once in awhile with a pattern change but to see this change every single day is wild. Again I still believe colder is the way to go but my resource here is letting me down. No red flag as I like to save them for the second half of winter.

12Z CMC and Euro have decided to have nothing happen until Thanksgiving Weekend. CMC phases the energy for a big rain storm. Euro has no phase and the northern stream energy bringing in mixed precip. with another shot of arctic air.

In summation... the big 3 global all have something different.

GFS - Cut off solution, big snow storm just to our East on Thanksgiving thru Saturday.
CMC - Rain maker for the weekend only
Euro - Shot of arctic air and light mixed precip for the weekend only.

tron777 wrote: ↑Thu Nov 17, 2022 2:31 pm 12Z CMC and Euro have decided to have nothing happen until Thanksgiving Weekend. CMC phases the energy for a big rain storm. Euro has no phase and the northern stream energy bringing in mixed precip. with another shot of arctic air.

In summation... the big 3 global all have something different.

GFS - Cut off solution, big snow storm just to our East on Thanksgiving thru Saturday.
CMC - Rain maker for the weekend only
Euro - Shot of arctic air and light mixed precip for the weekend only.

Les just roll the dice and even then the dice may fall off the table.

tpweather wrote: ↑Thu Nov 17, 2022 2:36 pm

tron777 wrote: ↑Thu Nov 17, 2022 2:31 pm 12Z CMC and Euro have decided to have nothing happen until Thanksgiving Weekend. CMC phases the energy for a big rain storm. Euro has no phase and the northern stream energy bringing in mixed precip. with another shot of arctic air.

In summation... the big 3 global all have something different.

GFS - Cut off solution, big snow storm just to our East on Thanksgiving thru Saturday.
CMC - Rain maker for the weekend only
Euro - Shot of arctic air and light mixed precip for the weekend only.

Les just roll the dice and even then the dice may fall off the table.

Seriously... We're just going to have to wait and see. I have no forecast confidence right now from Thanksgiving on.

tron777 wrote: ↑Thu Nov 17, 2022 2:41 pm

tpweather wrote: ↑Thu Nov 17, 2022 2:36 pm

tron777 wrote: ↑Thu Nov 17, 2022 2:31 pm 12Z CMC and Euro have decided to have nothing happen until Thanksgiving Weekend. CMC phases the energy for a big rain storm. Euro has no phase and the northern stream energy bringing in mixed precip. with another shot of arctic air.

In summation... the big 3 global all have something different.

GFS - Cut off solution, big snow storm just to our East on Thanksgiving thru Saturday.
CMC - Rain maker for the weekend only
Euro - Shot of arctic air and light mixed precip for the weekend only.

Les just roll the dice and even then the dice may fall off the table.

Seriously... We're just going to have to wait and see. I have no forecast confidence right now from Thanksgiving on.

When I saw the Indy nws throwing up its hands earlier today I knew we were in trouble. Yes a pattern change we believe but the Indy office is one of the best in the business and when they are doubting the models then I have no chance.

tpweather wrote: ↑Thu Nov 17, 2022 2:42 pm
When I saw the Indy nws throwing up its hands earlier today I knew we were in trouble. Yes a pattern change we believe but the Indy office is one of the best in the business and when they are doubting the models then I have no chance.

I think a lot of offices are being low key as they should when you see crazy model swings like this. I'm still leaning towards the idea of a more colder system and us getting rain to snow out of the deal. I still like this idea but on what day and how much of each p-type do we get is still much in doubt.

tron777 wrote: ↑Thu Nov 17, 2022 2:47 pm

tpweather wrote: ↑Thu Nov 17, 2022 2:42 pm
When I saw the Indy nws throwing up its hands earlier today I knew we were in trouble. Yes a pattern change we believe but the Indy office is one of the best in the business and when they are doubting the models then I have no chance.

I think a lot of offices are being low key as they should when you see crazy model swings like this. I'm still leaning towards the idea of a more colder system and us getting rain to snow out of the deal. I still like this idea but on what day and how much of each p-type do we get is still much in doubt.

I agree Les and that has been my forecast and not changing at the moment. I believe enough warm air next week for the system to start as rain but also believe enough cold air behind the storm to give us a period of snow. Still leaning towards the Thanksgiving day for rain and black Friday for the snow but as we can see by the models the timing has been different on each run with different outcomes.

tpweather wrote: ↑Thu Nov 17, 2022 2:53 pm

tron777 wrote: ↑Thu Nov 17, 2022 2:47 pm

tpweather wrote: ↑Thu Nov 17, 2022 2:42 pm
When I saw the Indy nws throwing up its hands earlier today I knew we were in trouble. Yes a pattern change we believe but the Indy office is one of the best in the business and when they are doubting the models then I have no chance.

I think a lot of offices are being low key as they should when you see crazy model swings like this. I'm still leaning towards the idea of a more colder system and us getting rain to snow out of the deal. I still like this idea but on what day and how much of each p-type do we get is still much in doubt.

I agree Les and that has been my forecast and not changing at the moment. I believe enough warm air next week for the system to start as rain but also believe enough cold air behind the storm to give us a period of snow. Still leaning towards the Thanksgiving day for rain and black Friday for the snow but as we can see by the models the timing has been different on each run with different outcomes.

Agreed... that has been my thinking too.

Trying to figure out how low we go Saturday or Sunday morning. I am going with 12-15 one of those nights but not sure which one. Having a clear sky and light winds should get us rather low even without snow cover.

airwolf76 wrote: ↑Thu Nov 17, 2022 12:42 pm will be watching some live streams on the Buffalo Blizzard. some areas got over 15 inches already

Yeah the show should be starting shortly for those folks. Was watching a chaser stream from Parish NY (downwind of Lake Ontario) and it was snowing so heavy you could barely see the car in front. He reported 17" there and it was still snowing over 2" an hour. HE then drove a few miles north and the sun came out! LOL

cloudy72 wrote: ↑Thu Nov 17, 2022 3:03 pm

airwolf76 wrote: ↑Thu Nov 17, 2022 12:42 pm will be watching some live streams on the Buffalo Blizzard. some areas got over 15 inches already

Yeah the show should be starting shortly for those folks. Was watching a chaser stream from Parish NY (downwind of Lake Ontario) and it was snowing so heavy you could barely see the car in front. He reported 17" here and it was still snowing over 2" an hour. HE then drove a few miles north and the sun came out! LOL

Very much like thunderstorms in Florida. One side of the road pouring and nothing on the other side.