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Pattern December to Remember

GaWx said:
Yeah, the Bleaklies (based on 0Z) are back to being their typical purely bleak. And as @Myfrotho704_ showed, even the latest CFS (12Z) is pretty bleak for most of its run except the last week, when it finally cools to near normal. What happened to all of those cold late Dec to mid Jan weeks on earlier CFS runs? Fortunately both of these models suck since the CFS often turns on a dime from one run to the next (like it did here to much warmer) and the Bleaklies are almost always bleak.
Anyway, enjoy the wx because it is the only wx you’ve got. ? The model twists and turns will keep us entertained, regardless.
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Possibly record warm January? And February?
 
Loganelliott99 said:
I honestly feel like the SE has a much better chance of seeing record heat than a snowstorm in January and February. I’m sticking to my guns and saying March will deliver for some
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Even in cold year betting against Jan-Feb with March is setting yourself up for disappointment. Sure it happens, but if climo tells us anything it’s to not hope for snow in March.
 
Here Brick...

snowstorm_jan_2018_raleighskyline.com_43.jpg
 
Webberweather53 said:
Here's the link to the ACCESS-S2 Monthly MJO forecast from the Australian BOM

http://www.bom.gov.au/climate/enso/#tabs=Tropics

In a La Nina winter w/ a slow-moving MJO wave like this, the NAO usually goes deeply negative when we reach phase 8. We should arrive there around or just before New Years, which is generally consistent w/ the circulation pattern on NWP models atm.
View attachment 97316
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Webber, who has the best track record with mjo rmm? Which one is most accurate in your opinion? I've heard the Australian mjo chart isnt that accurate fwiw
 
A strong +PNA can be a good and bad. Yes, a taller western ridge would allow colder air to push to the southeast, but a strong +PNA can also mean suppression and suppression is a nightmare here in the southeast when deep cold air is in place. A weaker +PNA would be better (weak ridging over the southwestern US to prevent lower heights to the east from causing suppression. A -NAO/AO combo with a -PNA/netrual and a -EPO should allow cold air across much of the country with transitional warmth east of the Rockies at times due to surface high pressures pushing off to the east. With the cold air that's predicted, there's definitely going to be cold surface high pressures coming south from Canada. Sure, we could see CAD/overrunning events in the near future.
 
StormWatch said:
A strong +PNA can be a good and bad. Yes, a taller western ridge would allow colder air to push to the southeast, but a strong +PNA can also mean suppression and suppression is a nightmare here in the southeast when deep cold air is in place. A weaker +PNA would be better (weak ridging over the southwestern US to prevent lower heights to the east from causing suppression. A -NAO/AO combo with a -PNA/netrual and a -EPO should allow cold air across much of the country with transitional warmth east of the Rockies at times due to surface high pressures pushing off to the east. With the cold air that's predicted, there's definitely going to be cold surface high pressures coming south from Canada. Sure, we could see CAD/overrunning events in the near future.
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Yeah, for very shallow Arctic cold/CAD wedging ice for the CAD areas including Atlanta, a +PNA is often not present and sometimes there’s a -PNA. But for a more durable and serious cold pattern and the best chance for a classic widespread major Miller A snow (deeper cold), a +PNA is often present. I’ve studied the stats for Atlanta. What happens is that the mean trough for, say, an AL/GA/Carolinas Miller A snowstorm is closer to the Mississippi River thus allowing for enough Gulf moisture to funnel up via WSW to SW H5 flow along with a surface low that travels ENE in the N GOM.
 
GaWx said:
Yeah, for very shallow Arctic cold/CAD wedging ice for the CAD areas including Atlanta, a +PNA is often not present and sometimes there’s a -PNA. But for a more durable and serious cold pattern and the best chance for a classic widespread major Miller A snow (deeper cold), a +PNA is often present. I’ve studied the stats for Atlanta. What happens is that the mean trough for, say, an AL/GA/Carolinas Miller A snowstorm is closer to the Mississippi River thus allowing for enough Gulf moisture to funnel up via WSW to SW H5 flow along with a surface low that travels ENE in the N GOM.
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I'm hoping the -NAO develops. Like I said it won't cause a +PNA, but even if we get stuck in a pattern like last year with a -NAO and a bad Pacific we may can still thread the needle unlike last year. Reason being the drier air and lower dewpoints this year and a lot more cold available in Canada and the northern US may give us just enough cold air this year.
 
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