Absolute Vorticity

Winter weather advisories, storm warnings, which chill advisories and even warnings will be widespread across the country. Blizzard warnings likely as well NW of us. That’s something else.

This will be a memorable event for a large chunk of the country.

I’ll be curious to see what ILN and other surrounding weather offices decide to do re: wind. Could very well be a situation where we have a winter weather advisory, wind chill advisory (or warning), and a wind advisory or high wind warning simultaneously. Wild times!

tron777 wrote: ↑Mon Dec 19, 2022 3:34 pm Wow... kind of shocked here but IND has already hoisted Winter Storm Watches for some of their counties North and West of IND Metro. 48 hours to go I can understand like in Minnesota but it's just a tad early in my mind for any counties in the Ohio Valley. Only guess I have is that they wanted to give the public more lead time since we are in the Holiday Traveling Period.

Agree ,they're close enough to that zone of bigger accumulations to play it safe due to the big travel days

Impact-wise, this storm will be high on the list for a variety of reasons. Not the same as 78 of course, but similar in the respect that smaller amounts of snow combined with frigid temps and wind will yield very hazardous conditions.

I’ll message my friend at ILN and see what they’re thinking. Per usual, he’ll probably ask that I don’t share too much info ahead of time.

Off topic but I just heard that Mr Perfect Tom Browning passed away today. Sad!!

https://www.wlwt.com/

Pete1 wrote: ↑Mon Dec 19, 2022 4:32 pm Off topic but I just heard that Mr Perfect Tom Browning passed away today. Sad!!

https://www.wlwt.com/

Just saw that...so sad. When the Reds were relevant.

Anyone seeing this that some European ensemble members and nam/rgem seeing a secondary low pop inner coastal. This would change the game with an energy transfer.

Phr0z3n wrote: ↑Mon Dec 19, 2022 4:53 pm Anyone seeing this that some European ensemble members and nam/rgem seeing a secondary low pop inner coastal. This would change the game with an energy transfer.
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I have mixed feelings about this... Should it occur, in my mind that would potentially allow for a weaker, more eastern solution but at the same time, it could be a QPF killer unless the transfer is ultra slow and the entire upper low is closed off at 500 MB ala Jan of 96 blizzard. That was an Apps Runner though that took it's good ole sweet time in doing the transfer and we got the snow from the closed upper low. Was a nice surprise! 1-2" turned into a foot of unpredicted snow! In this case, the Apps solution is dead in my opinion and I think the upper low closes off well NW of here.

18Z GFS looks pretty close to the 12z run. We are seeing only minor shifts now. The large swings should be done. We should have a locked in solution by tomorrow evening as we'll have most of the players on the field sampled by then.

IMO this always had a miller a look to it. There’s really nothing in the way to hinder an inter-coastal transfer.

18z gfs this should be where the transfer happens

The only thing I can think of is the low is to far from the coast for a clean transfer.

Bamwx talked about this as a possibility yesterday.

Don't forget the shortwave won't get fully sampled until 12z suite tomorrow at the earliest, so new trends at that time could have an impact on our expected accumulations

Wow! Over the last 90 days, the ICON or German model has barely been losing to the GFS. After the upgrade, now the GFS is losing to the ICON over the last 30 days! The GFS's score is even worse over the last 7 days!

Good Evening and we are about 18-20 hours away from maybe getting a forecast going but I see small things in the models that tell me something is up and will wait to the overnight model runs and maybe the noon ones on Tuesday. I still believe the Euro and of course the gfs is too far west. The model which has had minor changes but was the leader of this new pattern is the CMC. I believe at one time it had a Evansville-Cincinnati-Cleveland track. I still believe the models are just not getting this cold blast plus the jet stream really is on the war path later this week and to me this will develop the low further south late Wednesday or early Thursday. No model has shown a low forming in southeast Texas but with the attach of the jet and of course trough to me it seems the low may form on the coast. There is not a big southeast ridge to attach which can hold up things and this also has bugged me for sometime. Earlier I was trying to see why this storm was going west and yes a big high to the northwest and I mentioned how the high to the northeast was gaining strength over time so the models needed a place to direct this storm. Then I was trying to figure where the upper system may close off . If this happens in Iowa then the more western track makes sense but is that really going to be the place it closes off. What if this happens in southern Missouri instead and then the coastal low would make more sense.

I like to beat a dead horse but if this was just a Canadian source of air I believe the Euro would be correct or maybe even further west but models do not have much info on cross-polar air that just pours into the USA. Look at some of the pressures its showing in Montana and 1066 is nothing to sneeze at for sure. Hopefully by Tuesday things become clearer but with major storms and yes I believe this is one many times the details evolve late in the game. Coldest temp I see is in the Yukon at -55 and sure they have been colder but this cold is a broad area of cold and extends into Alaska and all the way into central Canada. Fairbanks is -33 at the moment so no doubt getting some of this cold air but they will rise slowly during the week as the bulk of the cold heads in the mainland USA. Okay enough of the rant from the old man but models are just a tool at the end of the day and is that the tool that helps me make a better forecast or is there another tool in the toolbox that may work better for this job.Sooner or later you must make a forecast and I believe at the latest is Tuesday night as some of the players will start to get in position. This is enough as I could fill this page up with other thoughts on how this plays out. I may be wrong and the Euro scores big and you just chalk if up as a loss . We will see soon enough lol.

I did listen to Kevin Robinson tonight because we know they use the Euro model. He is on with a major impact storm just like we are here with the cold and wind but he was very hesitant about snow totals. Maybe I am putting to much into what he said but the one thing stood out and that was the path of the storm is still not set in stone and we are talking about the Euro which has moved very little over the past few days.

Wonderful post as always Tim and you do bring up some valid points! It's just soooo hard for me to ignore the data. Remember way early on when the Euro had just a glorified frontal passage with a big low that cut West and hardly anyone believed it? I didn't. Euro was never a fan of an Apps runner. It had a couple of East Coast low runs which DT bit on hook, line, and sinker and got burnt as an example. Since then for the last several days, Euro has been rock solid with its track. CMC and GFS has moved a little bit but are coming inline. I maybe wrong as well and sure hope to be since my end goal is always more snow. But it is what it is. High impacts from a big temp drop, big winds, and a couple inches of snow is pretty much what we are dealing with per the majority of the data. There will be power outages in some areas. There will be road issues in some areas. Etc Etc. Everyone can agree on that.

HWO from the boys... pretty much the same points we have made here.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

The combination of very cold temperatures and strong wind will likely
produce dangerously cold wind chills Friday and Saturday, lingering
into Sunday for parts of the area. Wind chills well below zero are
expected at times during this period.

Strong winds are expected Friday into Saturday. Gusts of 40 to 50+
MPH will be possible during this period.

There is a chance for accumulating snow Friday through Friday night.
Even minor amounts of snow, combined with the gusty winds, may lead
to blowing snow and reduced visibility, causing impacts to holiday
travel.

Les there is more to this storm I believe and glad you handle the data part because that is not my strength. No matter how much snow we get the flash freeze is something that really needs to be talked about more often. Going from mid 40's to the single digits in a matter of hours with rain before the cold air arrives is going to cause problems. One thing to get the cold come in and have low 20's but single digits all day Friday with the wind blowing is not a good thing and really getting a few inches of snow could be the best possible outcome for travel. Not only will travel be rough but just walking on sidewalks and especially since we are talking about just before Christmas and the Christmas weekend where most people will be leaving their house sometime over the weekend. If this was mid-January the many folks especially older folks can get by without going outside for many days but the holidays is a time where many will still be out and about.

Have not thought to much about a coastal system and the area of disturbed weather along the GOM is moving slowly and may head up the east coast. Could there be a storm that forms besides the one heading in our direction and it may be possible and they end up being two different storms with little interaction.

tpweather wrote: ↑Mon Dec 19, 2022 7:16 pm Les there is more to this storm I believe and glad you handle the data part because that is not my strength. No matter how much snow we get the flash freeze is something that really needs to be talked about more often. Going from mid 40's to the single digits in a matter of hours with rain before the cold air arrives is going to cause problems. One thing to get the cold come in and have low 20's but single digits all day Friday with the wind blowing is not a good thing and really getting a few inches of snow could be the best possible outcome for travel. Not only will travel be rough but just walking on sidewalks and especially since we are talking about just before Christmas and the Christmas weekend where most people will be leaving their house sometime over the weekend. If this was mid-January the many folks especially older folks can get by without going outside for many days but the holidays is a time where many will still be out and about.

Yeah, I have agreed more with the flash freezing idea as today has went on. I think the temp drop is the real deal and the winds just aren't going to dry things fast enough. Those puddles will turn into patchy black ice and that can be very dangerous for travel even without the snow. Then, if the forecast for a couple of inches of snow is correct, blow that stuff around with 50 mph wind gusts and visibilities will be terrible. That can cause wrecks too. I am concerned about power outages too. I have beat that like a dead horse today. I'm with you, Trev, Bgoney etc on impacts. I'm not disagreeing with anyone there. Only the snow amounts are what I am focusing on now. The rest being discussed should play out as we've been talking about.

My friend’s daughter wants to drive to Cincy from Chicago. When do things get dicey up there?

Thanks for your insight!