We are still tracking a storm system for this weekend. Forecast models trended further north since my last post and model blend takes the storm right over La Crosse towards the northeast. This would place the snow on the northern third of Wisconsin and rain south. There will be a mix in between that will need to be pinned down. Also wrap around precipitation details and with a strong or deepening low wrap around can be interesting. Not sure about that yet but it's fun to speculate.
Full steam ahead with snow for the north. It's looking like a major snowstorm. Still expecting some minor track shifts. Models line up pretty well with CIPS mean. Both the GEPS and GFS ensemble spread is south of the control & operational, suggesting a southern shift is at least plausible. Early NAM is doing the same thing as everyone else. Consistency isn't that bad at this stage. I think of the biggest storms this year and note how all had consensus, then the 18Z came around and everything went haywire. Might be a bit of exaggeration but part of me is pretty confident in the images above, the other part is waiting for that chaos moment. Either situation we are prepared to deal with this time.
Make My Peace
As as storm chaser, I want the worst of every storm. Of course this forecast will bum me out a bit with the low pressure taking a track north of Oshkosh. In January I want snow. I've already made peace with SUN-MON system. If it comes back south, sweet! For now though we will keep looking forward.
The good news is that the upper level pattern does not immediately turn back to ridging in the west. The upper level pattern is a bit zonal and free-flowy like rainbow road in Mario Kart, but it's not a ridge thank god. It looks like our next storm system will be digging in across California and Rockies late next week. This is great to see I hope the models continue to show this. The details are up for debate and debate we will for the next 10 days. A little rhythm would be great and we want storms coming on a 7 day cycle. Usually each successive storm will track south of the previous storm. So if you miss out on the snow with #1, as of now; you have another opportunity to look forward to. Odds are #2 will track south of #1. The GFS takes #2 into the northern plains so somethings gotta give.
We still haven't managed a strong -PNA this winter and maybe we won't. The -PNA/ pos or neu AO relationship is gunpowder for Wisconsin snow storms. I think this shows in our precipitation trends thus far this meteorological winter.
January, February, March
I've spent a ton of time researching our current teleconnection relationships and setup. Based on Dec 2017 monthly averages, I will be monitoring the success of the following forecast. My thoughts are that we seem to be entering an active period with a northwest flow flavor. I believe a return to ridging in the west is inevitable. This time around it will be more stormy. Overall it looks like a typical La nina trend.
The image above shows two sets of analog precipitation anomalies:
- TOP SET - based on -QBO and -ONI (ENSO)(La nina) relationship. Shows colder conditions in the northern plains and western great lakes. I think this is a simplistic view with many teleconnections missing. Note the positive precipitation anomalies across the Appalachian mountains. This doesn't mean snow, this could be the signature of t-storms racing northeast in late winter and spring. That would put the snow up in our neck of the woods.
- BOTTOM SET - based on a matching algorithm that takes all teleconnections into consideration. This is similar to the top set but definitely distinct differences. Wants to bring the cold into the great lakes. A stripe of below average precip across northern Wisconsin is interesting. I also believe this suggests an active storm track across the great lakes. The precip anomalies are weaker.
Both suggest ridging in the west, so cold not going away long term. Both suggest storminess across the Ohio Valley. Probably not as many colorado lows. We'll see which set (if any) is correct.
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