Absolute Vorticity

tpweather wrote: ↑Wed Nov 16, 2022 4:39 pm

tron777 wrote: ↑Wed Nov 16, 2022 3:35 pm Currently in a break here but within the next hour, more flurries and snow showers should be occurring. Once the sun sets, we should see the activity wind down. We'll probably see a few more of these Thurs and Fri. Hopefully, some more brighter skies this weekend albeit very cold for the time of year.

Les I am just wondering as the action out to the west is with a little disturbance I wonder if we can get some additional snow showers overnight. Usually with snow showers they are like summertime showers that wind down once the sun sets but this activity may be able to last somewhat overnight and if so a better shot at getting a quick 1/2 inch in some places though most folks a dusting is more likely

I could see a dusting occurring for some folks this evening Tim. I wouldn't be surprised.

Can you imagine what kind of temps we would have with this air mass if much of the northern USA had snow cover. Really not a lot to speak of and not only how cold but the duration of this air mass is rather rare in November. I agree Les so far we are not bored and lets keep it that way until March.

tpweather wrote: ↑Wed Nov 16, 2022 4:44 pm Can you imagine what kind of temps we would have with this air mass if much of the northern USA had snow cover. Really not a lot to speak of and not only how cold but the duration of this air mass is rather rare in November. I agree Les so far we are not bored and lets keep it that way until March.

If there was a good snow cover to our NW, we probably would have broken some cold records but just a little short of this. Impressive certainly when you're 15 to 20 degrees below normal at any time of the year. Also as equally as impressive is the duration of this pattern even though we know it will soon come to an end as all patterns do.

Nice snow shower going on right now. Sticking to cars and roof tops at the moment. Pavement is wet for the time being.

Trying to figure out why such a -EPO ? In mid Nov? MJO wasn't anything to out of the ordinary in its strength while in 7 or any other phase for that matter. The days Leading up to such an anomaly, the NAO, AO , nothing to write home about . What pumped this ridge up on steroids ?

NWS made this post on FB interesting: [6:40 PM] Now that we have transitioned to nighttime, snow will more rapidly accumulate on roadways, especially overpasses and bridges. With both road and air temps cooling through the evening (eventually going below freezing), exercise extra caution if traveling! Snow showers will continue through early tonight, so take it slow if on the roads tonight as wet roads may quickly freeze as road and air temps dip into the upper 20s after midnight.

Bgoney wrote: ↑Wed Nov 16, 2022 6:35 pm Trying to figure out why such a -EPO ? In mid Nov? MJO wasn't anything to out of the ordinary in its strength while in 7 or any other phase for that matter. The days Leading up to such an anomaly, the NAO, AO , nothing to write home about . What pumped this ridge up on steroids ?

There is a massive storm over Eastern Russia producing 50-70 mph winds. So that big trough upstream, you've got to have an equally opposite reaction downstream, so a ridge in this case over Interior Alaska. But your question is really what has triggered this change? I'm not sure but maybe this might explain some of it? It's from the latest entry in Judith Cohen's Blog from 11/14. You can read the whole thing here if you want:

https://www.aer.com/science-research/cl ... cillation/

I normally don't follow his stuff due to the SAL Theory that has busted so much but I thought the part I have quoted below from the blog was interesting:

But November has been more interesting in regards to winter weather. Snow cover extent has been robust across East Asia but has stalled across Western Asia. Though as I have discussed in previous blogs based on recent research this dipole of positive anomalies in East Asia and negative anomalies in West Asia could be favorable for disrupting the PV (for example Park et al. 2020 and Wegmann et al. 2020). Meanwhile North American snow cover has expanded rapidly and is currently at decadal highs (see Figure i). For this and/or next week across the US a rare coast-to-coast below normal temperatures was predicted.

But the weather anomaly that has most got my attention is the potential for extreme cold in Siberia. The models have been playing now you see it, now you don’t with a Scandinavia-Dateline ridge-bridge across the Eurasian Arctic that would force low heights deep into Northern Asia (see Figure 8). It is my belief that a cold winter in East Asia, the Eastern US and Europe begins with an expansive cold pool in Siberia in the late fall and early winter. The longer that feature persists the more likely it is to disrupt the polar vortex and lead to an extended or repetitive cold period(s) for different regions across the mid-latitudes. The cold will persist as long as high latitude blocking persists in the North Atlantic sector but especially in the Scandinavian/Urals/Barents-Kara seas region. For what it is worth, the CFS predicts that it will be a prominent feature in December (see Figure 14) resulting in cold temperatures from the Urals to East Asia (see Figure 15).

young pup wrote: ↑Wed Nov 16, 2022 6:48 pm NWS made this post on FB interesting: [6:40 PM] Now that we have transitioned to nighttime, snow will more rapidly accumulate on roadways, especially overpasses and bridges. With both road and air temps cooling through the evening (eventually going below freezing), exercise extra caution if traveling! Snow showers will continue through early tonight, so take it slow if on the roads tonight as wet roads may quickly freeze as road and air temps dip into the upper 20s after midnight.

Today was the last 10 hour day too in Cincinnati for daylight until 1/25/23. We'll have under 10 hours of daylight starting tomorrow for the next 70 days. That'll help with nighttime accumulations!

tron777 wrote: ↑Wed Nov 16, 2022 7:00 pm

young pup wrote: ↑Wed Nov 16, 2022 6:48 pm NWS made this post on FB interesting: [6:40 PM] Now that we have transitioned to nighttime, snow will more rapidly accumulate on roadways, especially overpasses and bridges. With both road and air temps cooling through the evening (eventually going below freezing), exercise extra caution if traveling! Snow showers will continue through early tonight, so take it slow if on the roads tonight as wet roads may quickly freeze as road and air temps dip into the upper 20s after midnight.

Today was the last 10 hour day too in Cincinnati for daylight until 1/25/23. We'll have under 10 hours of daylight starting tomorrow for the next 70 days. That'll help with nighttime accumulations!

Sweet. That is a plus.

18Z OP GFS has completely lost the Thanksgiving storm idea on this run. This is classic GFS nonsense. It's northern stream dominant. Southern stream energy cuts off. Dry with seasonal temps into Sunday when we get clipped by some light rain with the S low finally over our S CWA. That's it. This is just the GFS doing GFS things. The Ensemble is much different. IT has trended even colder then the 12Z tracking the low just S of us on Thanksgiving with a cold rain in the 40s then a period of snow Black Friday on the backside with a nice deform band. Some individual members are overdoing it but an inch or two if correct, would not be impossible with temps in the lower 30s.

500 MB from 18Z GEFS Mean:


I am going against the Warmer Canadian and OP Euro runs due to the -NAO as shown above assuming the GEFS is correct of course. Now the 12Z OP GFS from earlier today was a decent run showing rain Thanksgiving to a period of snow on Black Friday. Probably 1" or less. Wasn't as snowy as the 18Z GEFS since the GEFS was further south with the storm track to begin with. So does the blocking have an influence on the Thanksgiving system for a rain to snow scenario? OR is it going to be a mainly heavy rain event and no blocking like the Euro correct? We shall see!

Great Posts tonight guys. What an early season puzzle and its always tough when there are some outliers that is not the norm this time of year. No doubt there has been more snow than usual in eastern Siberia and one reason they have been warmer than normal. I mentioned the other day models had parts of the area getting in the -60 - -75 range but has since back off though the latest run is colder than yesterday. Usually the heavier snows fall in October in that region but if they are getting heavier snows further north then a turn to much colder air is likely. Then we turn to blocking and how do we get some of that cold to transfer here. Still believe the AO goes positive for a few weeks in early December.

Watching the mjo and was headed for phase 4 but the latest shows it moved a hair towards phase 5. Is this just a blip or more to it and we should find out over the next few days.

Gfs and this models always gets goofy and though I truly believe the earlier run is most likely going to be close in terms of what may happen it makes you wonder what the heck change the latest run so much.

To early to say this is going to be a wild winter but this early start and what we are seeing around the globe makes you wonder if this winter is going to be wild and hard to predict. We can say that most winters I guess but so far November has been anything but normal with very warm conditions for 10 days being followed by 10 days of very cold weather. Yes we can see this in November but usually that amount of time for the warm or cold is 5 days or less with more normal days thrown in.

So we start to look at all the info that will be coming out but then to make heads or tails with that info and is there something we are missing. I love trying to figure out puzzles especially in relation to the weather but sometimes to much info is to much info.

Nice snow shower over Cincy / NKY right now that could put down a quick covering. Temps around 32-33 so watch for a few slick spots potentially on bridges and overpasses tonight.

tron777 wrote: ↑Wed Nov 16, 2022 8:05 pm Nice snow shower over Cincy / NKY right now that could put down a quick covering. Temps around 32-33 so watch for a few slick spots potentially on bridges and overpasses tonight.

Les that is the little area that was in western Indiana that has may it further east. I can see a few slick spots especially since its at night and road temps have fallen a lot over the past few days. I expect some flurries and snow showers on Thursday and doubt if any rain is mixed in. Another arctic front in here late Thursday night early Friday morning may give us the best shot at some accumulating snow as snow ratios go way up with arctic air plus if it hits in that 4a-9a time period.

Reading Dr Cohen posts and I just can't make heads or tails at times with what he talks about. Maybe I just believe Oct snows in Siberia is not as important as he has mentioned and really imo where heavier snows fall in November is more important.

after the polar plunge this weekend will be nice to see a warm up thanksgiving week

DT just put out a new video

The bills vs browns game this Sunday would be epic to watch!!

https://www.yahoo.com/sports/buffalo-co ... 47714.html

For Buffalo

...LAKE EFFECT SNOW WARNING REMAINS IN EFFECT FROM 7 PM THURSDAY TO 1 PM EST SUNDAY... * WHAT...Heavy lake effect snow expected. Total snow accumulations of 2 to 3 feet in the most persistent lake snows. The heaviest snow is expected late Thursday evening through Friday night when snowfall rates could exceed 3 inches per hour. Snowfall totals of up to 4 feet will be possible if the main snow band remains stationary for longer period of time. Winds gusting as high as 35 mph with produce patchy blowing snow.

Up for a road trip, Les?

Good Morning and we are up to 1.5 inches of snow at CVG. Still believe we have a good shot of getting to the 2 inch mark this week. I believe the snow showers later this evening and overnight have the best shot of sticking to the road as we have cooled enough. So I do expect some slick spots Friday morning. I will look more into the extended later but something you don't see in weather forecasting came out of the Indy office. They were talking about the extended forecast and yes we know how messy it looks but beyond 7 days they just threw in the red flag and gave up lol. They really said to many factors and no way they could make a guess what will happen beyond 7 days and I give them credit because it really is a mess and models I believe are having problems as we get into a different pattern next week.

Instead of looking at models this morning I decided just to throw out my thoughts on what may happen and really timing is the only issue. Very simple through Wednesday of next week. Cold through the weekend with some snow showers overnight into Friday morning and then bitter cold for this time of year through Sunday. A nice warming trend back to normal for the Mon-Wed period as we wait for a possible storm coming in here late next week. Thanksgiving-Sun of next week I expect a system to bring us a good chance of rain but the biggest problem is timing. Sometimes these deep cold troughs are hard to move out but I believe it will and some rain in by Thanksgiving into Friday. A chance for the rain to switch to snow as the storm departs and I could see an inch of wet snow. Next weekend looks cold as we wait for and extended milder period imo. The first two weeks of December look mild and sure a front every 5 days or so that cools us down briefly but the overall theme should be milder than normal as a more winter like pattern takes shape west of the Mississippi River .The next puzzle piece will be when do we flip back to winter and that is where I will stop because way to many factors that far out but yes a return is likely after mid-month.

It'll take me a little time this morning to go over the wonderful overnight and AM posts. For now, as Tim mentioned CVG received 0.3" of snow yesterday giving us 1.5" on the season. A 1/2" is possible early tomorrow morning so Tim, we may get to that 2" mark at CVG this week per our predictions.

Definitely saw more icy patches on elevated surfaces on the way in this morning, so expect another uptick tomorrow morning

Good Morning Les. Earlier this week I mentioned that parts of Siberia were forecast to have temps between -60 - -75. They switched back yesterday but this morning some forecasts of -80 is showing up. That is cold even for them. Seems models are just having problems everywhere. I do believe its going to get much colder in eastern Siberia as I expect the AO to go positive and the PV to become rather strong. They have got much more snow than usual for November and fresh snow plus deeper than normal can really get the temps low plus very little sunlight. Instead of going back and forth I believe they will get very cold. Do they reach -80 and I don't know but at least get into that -60 - -70 range looks likely. We do not want that cold to expand towards Europe as this would keep us milder longer. I believe we will need some kind of disruption in Dec but the good thing is much of Canada has decent snow pack so once we get the highway to bring it this way there should not be a problem of getting really cold once again in December. Will look at this next week to see if those temps are meeting the forecast and if they fall way short then my thoughts may be dead wrong.

So far I have not heard any report from the mainstream media that the expected snow squalls over the lakes this weekend is because of Climate Change. This happens quite often though in the past decade not quite as much. During the 60's-80's happened about every year to some extent. Getting a pattern where the wind is coming from the same direction for an extended period is a recipe for lake effect snows and since the waters are not ice covered this is a perfect storm for that area. Totals will very quite a bit in a short distance as these lake effect snows tend to go over the same area for hours at a time. I know the Buffalo-Cleveland game is Sunday in Buffalo though by then hopefully the heaviest of snow as fell. Can they clear the field and my guess is yes because this has happened before. I loved playing football in the snow as a kid though sometimes the football would become frozen and wow that would hurt if the ball hit you directly. Also punting the ball was like hitting a brick.

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.

airwolf76 wrote: ↑Thu Nov 17, 2022 1:39 am DT just put out a new video