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Ostrich December

Beautiful morning here!
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If the Euro holds for the 3rd run in a row, we really might be on to something significant (maybe not Winter weather) but some sort of big time dynamic system. I feel like this coming Euro run & ensembles might be one of the most important ones as far as sniffing out a storm so far this season.
 
The coldest air in the entire N hemisphere settles into the NW Territories by day 10 on the Euro.

If we can keep the -NAO gravy train going past mid-month, and force a few transient waves in the northern branch of the jet to slide underneath it into SE Canada & the Great Lakes, we might be able to tap into some of that.


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So the indices don't look bad:
PNA - Looks to go slightly negative, but then go slightly positive in the LR.
NAO - Is currently slight negative, but actually looks to go father negative in the LR.
AO - Is currently moderately negative but looks to go farther negative in the LR.

CPC - Climate Weather Linkage: Teleconnections (noaa.gov)
 
A sneaky, fast-moving MJO wave looks like it's gonna propagate thru the Pacific later this week & beyond.

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This particular wave looks like it's going to be forced almost exclusively by wave breaking in the N Pacific storm track (as there's no corresponding signal in U850 or OLR). Hence, lacking a significant moist convective component, this particular subseasonal wave had more limited predictability than what typically accompanies the MJO.

I bring this up because interference with &/or a reprieve from Indian Ocean-Maritime Continent convection in early winter is a win in my book and may be why some NWP are more gung-ho about the -NAO this week sticking around past mid-month.


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Webberweather53 said:
Unlike so many -NAO/+EPO regimes we've seen in the past, the one that's coming around the corner could have much easier access to true Arctic air thanks to this week's -WPO that'll deposit air from NE Siberia (the coldest place in the entire N hem) straight into Alaska & NW Canada. I'm legitimately going to be interested in what this pattern holds thru Christmas if the -NAO doesn't dissipate.

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Per Maxar’s -AO/+EPO analogs, the SE actually averaged colder than normal with a +PNAish look to the US temperature anomalies. The same can be said for MJO phase 4 with a -AO fwiw.

*Corrected
 
GaWx said:
Per Maxar’s -AO/+EPO analogs, the SE actually averaged colder than normal with a +PNAish look to the US temperature anomalies. The same can be said for MJO phase 4 with a -AO fwiw.

*Corrected
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Historically, in -NAO/-AO/+EPOs, the +EPO backs off some and the AK vortex retrogrades towards the Aleutians, opening up the door for +PNA

I played around w/ a few composites, I think this is as close as I can get at a monthly scale for the hemispheric scale pattern in a -AO/-NAO/+EPO during Dec.

I even used an older, cooler base period to try and bias the temperature composite warmer but it's still arguably vodka cold.

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