No, now it’s happening!!! Tree crushing winter inbound..
ITS HAPPENING!
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Wintry Winter 2019-20 Discussion
- Thread starter Snowfan
- Start date
Webberweather53
Meteorologist
2012-13, 2009-10, 2008-09, 2003-04, 2002-03, 1987-88, 1986-87, 1984-85, 1976-77, 1972-73, 1970-71, 1965-66, 1962-63, 1959-60, & 1957-58 are a good subset that's "helped" us in the past.
While some of these actually didn't even result in the classical -AO response at the surface and arguably made the pattern "worse" in a hand-wavy sense, you could actually argue that those cases w/ SSWEs that enticed a stronger +AO in the weeks leading up to big winter storms down here actually set the table for some of our most famous southern sliders like Feb 1973 & Jan 1988 to name a few.
On average, sudden stratospheric warming events do in fact help us and the corresponding temperature anomalies in the 60 days following a SSWE are statistically significant (shown in stippling below).
Virtually all of this significance emerges as a result of SSWEs during El Nino winters like this year, there's no signal favorable or unfavorable in NINA winter SSWEs, but do notice that the southeast ridge following SSWEs in NINA winters is considerably weaker than before said event, so you could certainly make the argument it's helping us as well.
In essence, yes SSWEs are far from guaranteed to "help" us but they do so far more frequently in El Nino winters when our base state is more receptive to cold/snow here. You also should notice that in NINO winter SSWEs like what we might see this year, our pattern shifts from being +PNA heavy before the event to being dominated by -NAO/AO thereafter.
For more see:
https://www.earth-syst-sci-data.net/9/63/2017/essd-9-63-2017.pdf
Watch that UUL in S CA! It’s gonna be $$$
All we need is cold when it arrives
All we need is cold when it arrives
SnowNiner
Member
Will this be the winter where we have both an -EPO AND a -NAO? Ok, no I'm sorry that's silly. I should be punished. Nevermind.
Webberweather53
Meteorologist
It’s very difficult to get both simultaneously for any extended period of time because the same physical mechanisms that typically create -EPOs also destroy -NAOs. Stratospheric warming events can help in this regard
ajr
Member
Allan seems to agree with some of the building consensus we’re seeing regarding late Dec into JF
Jon
Member
The pac low isnt all that bad assuming we pop a +PNA
Here's a composite of all December snowstorms in the 2000's for NC. (Snowstorms being significant snows in any part of the state) I left out ZR events and small "trace only" events so as to not skew the mean toward a pattern that doesn't normally produce.
N=13
_NAO, Pac low, ridge over aleutians.... Similar pattern was seen in the Famous 2010-11 winter with storms through Dec & Jan with 10 storms from Dec 4 to Jan 22.
One thing I'm not crazy about is the lower heights in the SW on the GEFS. Maybe it's transitory. But over the last few years, there has been a tendency for that to repeat. Probably fits somewhere in the composite for rain events or mixed events here. Anyway, if the NAO is negative enough, we can deal with some troughing there. But I'd like to see it kick out and get more ridging all along the west coast.
SnowNiner
Member
Yep beat me to it. We stay cool in that pattern I think because of the -NAO but until the trough comes east with ridging on the west coast we just stay seasonal.
We get the set up that Jon posted and we're butter.
A lot of that is being caused likely from how active the STJ is, can definitely tell by 250mb winds
I can envision where disturbances move east/northeast from the southwest and then reform somewhere over the SE in a Miller B fashion. Having blocking up there will allow high pressure to be in the vicinity of where we want it, but our storm track won't be favorable and the transport of cold into the region won't be ideal. So seasonal to cool, like you said, seems most likely. But hey, we're talking about the end of November/beginning of December. Hard to really gripe too much. rn.
Yep, and I definitely like that. But we want that whole pattern shifted to the east, ideally.
Yeah, I’m assuming with it amped up that much that increases the chance for more uglier setups that don’t work to well
Seems like the only thing it does is send record cold and snow into Europe.
NoSnowATL
Member
My new favorite follow on Twitter, way better then JB.
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Jon
Member
My new favorite follow on Twitter, way better then JB.
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Dang! Model cycle difference on weathermodels? It must be a commercial feature because I’m not seeing that in my available parameters. That would make comparing runs much easier lol.
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And the upper midwest apparently. Like last winter. Winter 2018-19 actually happened for them.