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Pattern January 2020 - Operation Thaw Alaska

What in the world is "MVP"?

@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....
 
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.
 
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).
 
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?
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...


1579103604936.png


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 ?
 
I wouldn’t rule out more snow/sleet further south given the pattern before hand. Certainly not sold on all ZR or rain. 1F3ED48F-9720-4B03-B4E4-9BB05ECDC161.jpeg
 
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