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Pattern January 2020 - Operation Thaw Alaska
- Thread starter KyloG
- Start date
FWIW this Saturday on the NAM. Also has a better CAD signature this run and more precip ahead of the line.
Webberweather53
Meteorologist
Not surprising given it was a year with an advancing Nino. I wouldn’t be shocked to see a really big central pac mjo event in Feb or Mar that sends us on our way to a nino for 2020-21. Could be staring down the barrel of our 3rd winter in a row with a nino, ironically 2 of those featured a strong SE ridge. (Facepalm).
Maybe the 3rd time will finally be the charm?
Seems about right, models always tend to rush a true pattern change... little glancing cold blow here and there, then complete flip to cold for Fab Feb.
Oh great...so we can go ahead and cancel Dec 2020. This doesn't look like it's going away.
Jon
Member
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I don’t understand what it takes anymore
At the end of the day let’s also remember the basics. Looks how much RUN to RUN variability there is in the ENS runs much less the OP runs. Euro op is telling IMhO. Keep watching that shortwave back further SW. let’s see if that keeps happening
What a kick in the ?
The dang mountains in Gatlinburg can’t even get a nice chance.
The dang mountains in Gatlinburg can’t even get a nice chance.
Jon
Member
Multivariate PNA index. Carl Schreck set to figure out which MJO events impact USA temps and which ones do not. (Ex. We are in phase 8 and nothing happened, why?)
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John1122
Member
The Multivariate PNA. Basically if the PNA is Neutral or negative the MJO phase doesn't matter a lot.
Oh geez. I quickly glanced at it and it's a variant of the PNA so of course, the MVP is negative as we are coming out of a strong -PNA period.
Jon
Member
It’s not the PNA that’s the point, it’s multivariate. That’s why the MVP has a 0.57 correlation with the CPC’s PNA index, as in, it’s not close to being the same as the PNA index.
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Good post as was yours from yesterday.
Jon
Member
Yeah, the point is more this:
if the MVP stays + or - when we are in Phase 7 it will likely not lead to Eastern cold.
Or if the MVP stays - or goes neutral, it will likely not lead to eastern cold.
Obviously the PNA is binary. + leads to cold East, - leads to warm East. That’s not the case with the MVP and in this research it correlates the 3 measures (-,0,+) with the MJO phase and outcomes on temp in the US
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I haven't read the white paper, but a +PNA is a ridge in the west and a -PNA is a trough there. What does the same height field look like with a -MVP vs a +MVP. Any pictures?
Icon has that ridge you wanted over Vegas
That was Kylo. But I guess that's good? The trough is still not oriented very well. Bet it goes to zero again in the snow dept.
Icon is about to go to pound town 
Icon was a fail but damn close
Lol ok
@Rain Cold and I have joked about there seemingly always being a newly discovered three letter deal every winter. Well, for 2020 it is “MVP” lmao. I’m going to call it the most valuable player index.
In the meantime, we know there will likely be still another new one by next winter...one that nobody is aware of right now...and then another one the subsequent winter and so on and so on....
Red is actual
Green is proposed
Green is proposed
This looks way more reasonable when you try to recover from temps in low teens. Way too many cliff divers last night take model output verbatim. 6z GFS. 
This would certainly have significant implications for our second storm and most likely really help us out .. icon has been consistently showing some wacky solutions with this first storm and I wonder if it’s into something .. but the others just don’t show anything like that so it’s hard to get behind with confidence ..
We just need the storm to speed up and come on the heels of cold air that has left and dropped dry stable air east of the blue ridge at the surface.
Look at all that blocking just barely licking the NAO region .. we can’t give up before we even get into February with a look like this
John1122
Member
Here's the site that monitors it. Still considered experimental.
https://ncics.org/portfolio/monitor/mjo/extratropics/
GeorgiaGirl
Member
ICON actually winds up getting precip as far north as me, but it's warmer at the 850s. It's apparently still icing though at least at the start (who knows otherwise if it's warm bias is a problem there).
Jon
Member
The way I understand it there's no simple 500mb composite for those states. You'll probably get something similar to the CPC look, but since it's multivariate it's not only going by 500mb anomalies as a measure of the state of the MVP. The PNA is simple because it's either on or off, 1 or 2, + or -. MVP is different becuase it includes tropical forcing as a variable, as well as streamfunction. Because of this it's likely to not correlate with what you're used to seeing, but probably correlates somewhat with the CPC PNA index (although only 0.57) Sorry I don't have an easy answer, it's new to me.
The best I can do is show you the 200hpa stream function composite and the summary the paper gives for the graphic...
The 200-hPa Rossby wave train represents a form of the PNA pattern, although the exact positioning of the circulation centers is shifted 5°–10° southward compared with Barnston–Livezey (1987) version that is used by the NOAA/Climate Prediction Center (NOAA/CPC). That shift is insensitive to extending the MVP domain all the way to the North Pole. After projecting the pattern in Fig. 1 onto unfiltered data, the resulting time series has a 0.57 correlation with NOAA/CPC's PNA. While this correlation is significant at the 99.9% level, more than two-thirds of the variance is unique between these indices.
The 850-hPa streamfunction (Fig. 1b) shows the lower-tropospheric reflection of the 200-hPa wave train. The pattern contains an anomaly dipole over the Pacific with one center near 40°N and the other center near the equator. The nondivergent winds inferred from this dipole represent variability in the 850-hPa zonal winds near Hawaii.
A large anomaly near Hawaii dominates the OLR pattern (Fig. 1c). The anomaly represents suppressed convection when the MVP is positive and enhanced convection when it is negative. The anomaly is surrounded by opposite signed anomalies to the north, east, and west. The central anomaly extends northeastward to North America, which parallels the anticyclonic wave breaking (Thorncroft et al. 1993; Ralph et al. 2011) suggested by the 200-hPa streamfunction pattern (Fig. 1a). When the MVP is negative, this combination of an anticyclonically breaking trough with enhanced convection is consistent with a tropical moisture plume and the formation of an atmospheric river (McGuirk et al. 1987; Ralph et al. 2011).
Also riding on the west coast is beginning to increase at the end of the run while energy drops in the Midwest towards us again would be fun to see the model go out 360 hours ?
This Saturday on the GFS
I wouldn’t rule out more snow/sleet further south given the pattern before hand. Certainly not sold on all ZR or rain. 