Wintry Winter 2018-19 Discussion

[Brick Tamland]

And another one calling for above normal snowfall. Add WxSouth to the list with DT and Huffman.

Winter Outlook: The easy part of this forecast is probably the wetter side. I have a breakdown of the past few Ninas and Nnos and how they have NOT behaved as climo would suggest. Long story short though, it appears a more likely scenario for this type of Nino is to be a return to a very active southern Jet stream, at times blended with phasing northern Cold stream, with plenty of precip going on in the south. It has already begun, if you haven't noticed.
Long range seasonal models paint a strong Aleutian Low , which in turn means a colder, active Southeast United States. The Sea Surface Temps profile and the Jet stream forecast all look similar to the Nino's of 2002, and 2009. Again though, very unlike the recent 2 Nino's we've had. So if my guess is correct (and some model guidance) get ready for plenty of weather action, every few days, with hardly any let up, from now until next Spring. When that cold meets the moisture in the MidSouth and the Appalachians, quite often I think above normal snow will result, just like 1986-87 2002-03, 2009-10 El Nino Winters. Plentiful Cold Rains the next few months, before a Super Drought begins development the subsequent years.

 

[RollTide18]

Well, this is either going to be one of the best winters ever or an epic bust that will be talked about for years on here. I'm betting the truth lies somewhere in the middle.

 

[Webberweather53]

I really want to see where we are in reality around Thanksgiving and what the models are spitting out for early December. The ridging across the north Pacific into Alaska and the arctic circle along with the Scandinavian ridge has me intrigued.

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There are hints in the background that we may be conforming to the classic NINO warmth as a positive mountain torque event and re-emergence of subseasonal tropical forcing into the Pacific favors an extension of the Pacific jet near the end of November and going into early-mid December, at this time of the year that favors warmth across much of the contiguous US east of the Rockies, with more seasonable temps (but still a warm signal nonetheless) in the southern tier. Imo, it's paramount that you get a good grasp of how mountain torques play into the overall pattern and the nuances involved w/ Rockies & Himalayas torque because they're usually a very reliable precursor to what the atmosphere will subsequently do about a week or so after they developed. In addition to frictional torques, the atmospheric response to the mountain torques creates a pattern that usually destroys the initial mountain torque, causing it to flip sign (positive mountain torque going to negative mountain torque & vis versa), and then leading to a signal that's of the opposing sign. This occurs on timescales that are much shorter than that of the MJO for instance, although it'll be closer than usual in a year like this where the return period of the MJO is close to 30-40 days

 

[Chattownsnow]

Anyone think that the warmer than average SST's in the Atlantic and gulf could be a problem this winter? In the past it seems the models have under estimated the SER when SST's are high in the Atlantic and the gulf and that can really throw a wrench in things. Going through winter in 2009-2010 SST's were below normal and the SER was pretty much non existent, and I Specifically remember a SE trend on storms coming through the SE. Same exact thing for 2010-2011. Modeling just doesn't seem to pick up on this feature in advance very well, possibly due to sampling of data out over the waters here I imagine. And maybe this is why we get the dreaded NW trend on storms all the time.

2002-2003

here we are currently

Of course it could just be that the cold air intrusions into the SE caused the SST's to be cooler than average in these winters. I don't know. I'm bored and not much is going on so I just thought I would throw this out there.

 

[Jessy89]

Did anyone living close to the Tennessee/nc state line see any snow fall yesterday or last night? Headed to pigeon Forge for a night from upstate South Carolina. Some of the highest elevations have what appears to be a dusting of snow at the very top. I’m curious did anyone see it fall?

 

[Rain Cold]

Any of those other seasonal models come out yet, like the the Jamstec, UK, or JMA? All I’ve seen is the Yuro.

 

[Jon]

Any of those other seasonal models come out yet, like the the Jamstec, UK, or JMA? All I’ve seen is the Yuro.

JMA seasonal is out in a day or two, the 4 week forecast is zonal and not cold up until Dec 6 which most long range forecasts are predicting.

I posted the Beijing Climate Center seasonal here:


January is cold, other than that it’s normal but pretty decent patterns at 500mb thru March. It’s not a model talked about much but they’ve improved their graphics year to year, and upgraded the model this year. It’s ran once monthly like the JMA 3mo model.


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[Rain Cold]

JMA seasonal is out in a day or two, the 4 week forecast is zonal and not cold up until Dec 6 which most long range forecasts are predicting.

I posted the Beijing Climate Center seasonal here:


January is cold, other than that it’s normal but pretty decent patterns at 500mb thru March. It’s not a model talked about much but they’ve improved their graphics year to year, and upgraded the model this year. It’s ran once monthly like the JMA 3mo model.


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Awesome, thanks Jon!

 

[Jessy89]

This is a interesting look for Thursday morning. We all know these cold air wedges trend colder closer to time. Some people could see a slippery morning. Something fun to watch none the less!)

 

[NCSNOW]

After this weeks Rain Greensboro will be sitting in 6th place all time wettest year on record. Don Sutherland on amwx posted a lot of southeast cities and calculated in the 1-3 inches we would see this week. Pretty impressive.

Per Don:
During the November 12-13 period, parts of the Southeast will likely pick up 1"-3" of rain. In the wake of the storm, 2018 will likely become among the 30 wettest years on record in a number of cities in Georgia, South Carolina, and North Carolina. Wilmington, NC, which has already picked up a record 90.65" precipitation this year will add to its record.

Below is year-to-date precipitation, the current rank for 2018, and scenarios for the ranking based on 1"-3" rainfall.



Records in the above cities begin as follows:

Athens: 1857
Atlanta: 1878
Elizabeth City: 1934
Fayetteville: 1910
Florence: 1948
Greensboro: 1903
Raleigh: 1887

 

[Jon]

JMA seasonal update:




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[Webberweather53]

JMA seasonal update:




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If December ends up being average or even slightly below & stormy, and we manage to get one big dog in central NC, that's a huge win in my book.

 

[Webberweather53]

The tail end of November into early December certainly is starting to get my attention as a period that could yield a nice storm near the eastern US as a massive Scandinavian blocking high retrogrades westward towards Greenland, the classic way we get really nice -NAOs. Unlike this past week, we're starting off with a much bigger Scandinavian blocking ridge which means more planetary vorticity advection, and a bigger ridge makes it to Greenland (all else equal) vs this past week, we will have a deeper Aleutian Low as the Pacific jet briefly extends in response to a + east Asia mountain torque earlier this week and tropical forcing shifting into the West-Central Pacific. There's usually an inverse relationship between the Aleutian & Icelandic lows because strong Aleutian lows discourage downward WAFz propagation into northern North America and Greenland, effectively discouraging deep Hudson Bay vortices (+TNH) which often couple to +NAOs, a pattern we've become very familiar with the last several years. We'll see what happens but this period beginning after November 25th and going into the first several days of December might hold some promise if we can get another bounce or two to come in our favor. I personally think the NE US stands a better shot to really score a nice winter storm at least earlier in this timeframe, but we'll see!

 

[Kylo]

Here is the Nov CFSv2 seasonal for DJF. Maybe it will score coup as every other seasonal is stormy/blocky for the east/southeast.

 

[Rain Cold]

Here is the Nov CFSv2 seasonal for DJF. Maybe it will score coup as every other seasonal is stormy/blocky for the east/southeast.

View attachment 7311
View attachment 7312

The CFSv2 is an idiot. They need to roll the v3 out. Not just saying that because it's warm. It's just always warm. It's hard coded to be warm. Every now and again, it breaks character and gives you a wtf cold map, but that is surely accidental.

 

[BHS1975]

The tail end of November into early December certainly is starting to get my attention as a period that could yield a nice storm near the eastern US as a massive Scandinavian blocking high retrogrades westward towards Greenland, the classic way we get really nice -NAOs. Unlike this past week, we're starting off with a much bigger Scandinavian blocking ridge which means more planetary vorticity advection, and a bigger ridge makes it to Greenland (all else equal) vs this past week, we will have a deeper Aleutian Low as the Pacific jet briefly extends in response to a + east Asia mountain torque earlier this week and tropical forcing shifting into the West-Central Pacific. There's usually an inverse relationship between the Aleutian & Icelandic lows because strong Aleutian lows discourage downward WAFz propagation into northern North America and Greenland, effectively discouraging deep Hudson Bay vortices (+TNH) which often couple to +NAOs, a pattern we've become very familiar with the last several years. We'll see what happens but this period beginning after November 25th and going into the first several days of December might hold some promise if we can get another bounce or two to come in our favor. I personally think the NE US stands a better shot to really score a nice winter storm at least earlier in this timeframe, but we'll see!

View attachment 7310

Look at that parade of arctic highs


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[Rain Cold]

The tail end of November into early December certainly is starting to get my attention as a period that could yield a nice storm near the eastern US as a massive Scandinavian blocking high retrogrades westward towards Greenland, the classic way we get really nice -NAOs. Unlike this past week, we're starting off with a much bigger Scandinavian blocking ridge which means more planetary vorticity advection, and a bigger ridge makes it to Greenland (all else equal) vs this past week, we will have a deeper Aleutian Low as the Pacific jet briefly extends in response to a + east Asia mountain torque earlier this week and tropical forcing shifting into the West-Central Pacific. There's usually an inverse relationship between the Aleutian & Icelandic lows because strong Aleutian lows discourage downward WAFz propagation into northern North America and Greenland, effectively discouraging deep Hudson Bay vortices (+TNH) which often couple to +NAOs, a pattern we've become very familiar with the last several years. We'll see what happens but this period beginning after November 25th and going into the first several days of December might hold some promise if we can get another bounce or two to come in our favor. I personally think the NE US stands a better shot to really score a nice winter storm at least earlier in this timeframe, but we'll see!

View attachment 7310

Hey man, I got the Scandinavian ridging, the NAO, the Low of Aleutia and tropical forcing. I even know a little about TNHs, mountain torquing, and exponential planetary vorticity advective coriolis deviation convergence. But for the life of me, I can't figure out what a WAFz is? What that?

 

[Kylo]

The CFSv2 is an idiot. They need to roll the v3 out. Not just saying that because it's warm. It's just always warm. It's hard coded to be warm. Every now and again, it breaks character and gives you a wtf cold map, but that is surely accidental.

For our last weak nino this is what the Nov run had v/s what verified. Not bad

 

[Rain Cold]

For our last weak nino this is what the Nov run had v/s what verified. Not bad

View attachment 7313 View attachment 7314

Bless it's heart. It tried.

 

[Kylo]

Bless it's heart. It tried.

The UK did fairly well that winter though. +NAO, atlantic ridge, displaced GOA low, ridging in west.