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Pattern December, Make analogs relevant again

GaWx said:
Although Webb is 100% right about the GFS cold bias, others have pointed out that models often have trouble with modeling how far south low level very cold air will go with big and very strong Arctic highs. I think that the major 12/1983 and 1/1982 (snowjam) cold outbreaks are good examples of this. Has this problem been perfected? I don't know but I'd be wary about the possibility of it getting colder than even the coldest GFS runs have shown. This is no ordinary setup. I can't even recall anything like what we're seeing now, all 3 major models repeatedly showing these huge highs. Something highly unusual apparently is going to happen.
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See my post immediately above this one in response to Shawn. If you have any questions about what I discussed feel free to ask!
 
Webberweather53 said:
See my post immediately above this one in response to Shawn. If you have any questions about what I discussed feel free to ask!
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For the upcoming modeled pattern in the 8-16 period does that resemble any past southeast overrunning winter storms? I know the +NAO doesn't help.
 
RollTide18 said:
Jan85Coldest.png
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Wow thanks for posting this. Holy crap
 
I don't recall specifics but I know in the early 80's as y'all have well documented, there were some brutal arctic outbreaks. I grew up on a farm, among other things we had small amount of cattle and I remember every day having to take an ax to break the ice so the cows could get water. I even remember sliding on the ice on my grandparents pond on Christmas day.... we haven't had anything close to that since. Might've been '83 because I was around 12 yrs old.

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January 1977, January 1982, December 1983, January 1985, and December 1989 all featured prominent arctic outbreaks that would have impacted everyone on here. Also, I seem to remember that the 60's featured several prominent events with December 1962 probably being the biggest one. I feel like that such events have greatly been diminished over the past few decades and the only things that we've had remotely since have been February 1996, January 2003, and January 2014.
 
Kylo said:
For the upcoming modeled pattern in the 8-16 period does that resemble any past southeast overrunning winter storms? I know the +NAO doesn't help.
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Jan 88 storm, had + NAO
 
1300m said:
That's the million dollar question haha. Will the EPO verify off the charts? If so then absolutely, it's game on, but I've seen this movie before.
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Oh me too. I'm trying to think when last time super high came down
 
Kylo said:
For the upcoming modeled pattern in the 8-16 period does that resemble any past southeast overrunning winter storms? I know the +NAO doesn't help.
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For overrunning/Miller B storms, I discovered in my analyses of the large-scale patterns that encapsulated major storms like December 1989, February 1973, February 2014, et al, that the sign of the NAO didn't help nor hurt us, if anything a +NAO could help, but what really matters in an overrunning event is getting Rex Blocking (high latitude blocking ridge directly north of a trough) and split flow upstream over western North America, or the North Pacific (-EPO/-WPO) because this forces shortwaves initially in the mean streamflow to get stuck underneath the block and provides a disturbance for us to work with in the southern branch of the jet. As these systems emerge from the other side of the Rex block in the southern branch of the split jet, they migrate towards the east-northeast and confluent flow underneath the base of a large-scale vortex over southeastern Canada (+TNH) shears them out, hindering excessive amplification (which is good for the SE US), while the stretched/sheared wave provides an elongated/prolonged west-southwesterly fetch of rich Gulf of Mexico and northeastern Pacific moisture that presumably overrides an antecedent arctic airmass (if one exists) thus leading to overrunning...
 
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WxSouth says winter is coming.

I covered a lot of meteorological ground in tonight's update at the blog. Short, medium range and even speculated into mid January, on a variety of topics. Where models have missed things so far, and how the upcoming various indices are likely to be off, once again. I was taking issue with the warm/dry Southeast outlooks that were issued in November, and there's no change there--more snow and ice is almost a certainty in our future as we go through Christmas Day and especially going toward the New year and into January , as a whole host of features is in favor of such. Blocking, extreme ridging up north, strong Arctic Highs pressing south, split flow eventually undercutting the Cold air, the MJO entering and dying in Phase 8, repeated flux attacks on the Polar Vortex, weakening it and allowing cold air to repeatedly come very far south the next few weeks. This is nothing like the last 2 Boring Winters. The devil is in the details though, and still that Christmas Eve/Day storm has a few tricks up it's sleeve for snow in Kentucky, Tennessee and northern Mississippi to Arkansas. I won't rule out a slightly further east track, east of the Apps either, with change to snow on East Coast.
Right now, I wouldn't focus on the single model runs, but the overall pattern for an extended time frame--it looks active and very Winter-like with several big ticket items on the map for weeks to come.
 
Yeah we need a good one to make of for the last 2 years of bugs not dieing off.


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