Absolute Vorticity

tron777 wrote: ↑Wed Dec 15, 2021 7:14 am Minnesota has never registered a December Tornado. Could today change that? Let's hope not. The winds are going to be an issue for a lot of folks even without t-storms. Remarkable to see a moderate risk issued for Iowa and SE MN in December! Practically unheard of.

Bgoney wrote: ↑Wed Dec 15, 2021 7:29 am

tron777 wrote: ↑Wed Dec 15, 2021 7:14 am Minnesota has never registered a December Tornado. Could today change that? Let's hope not. The winds are going to be an issue for a lot of folks even without t-storms. Remarkable to see a moderate risk issued for Iowa and SE MN in December! Practically unheard of.

Yea, I saw satellite pics where there is snow on the ground atm where part of the mod risk is

cloudy72 wrote: ↑Wed Dec 15, 2021 11:07 am Historic wind storm is underway in the central US :

Current wind gusts:

107 mph at Lamar, CO
89 mph at Las Vegas, NM

cloudy72 wrote: ↑Wed Dec 15, 2021 11:17 am Current mesoanalysis shows a well defined squall/bow flying northeastward into western Kansas. Winds have gusted over 100 mph with this line.


Squall-Line.PNG

tron777 wrote: ↑Wed Dec 15, 2021 2:02 pm Quick long term thoughts:

I am seeing more and more models showing a dual blocking structure to the North American 500 MB pattern. You've got an Alaskan ridge or -EPO that is centered a little too far west for us, but you get the arctic air dumping into Western Canada and into the Northern Rockies / Plains. We've also got a nicely placed -NAO pushing well into Greenland. However, at the same time we continue to have a robust -PNA which will keep the storms crashing into the West Coast and ridging will want to fight the cold air attacks as they come in with each storm. By the time we get towards New Year's and beyond, I think if the MJO does get into deep Phase 7 if not even Phase 8, the cold shouldn't have a problem getting down to us. I think the core of the coldest air stays NW of us which is fine. We just need 20s and 30s for snow which would work. Again patience is needed but I am really beginning to like what I see as we approach New Year's and beyond

A check of the Tellies shows the AO and NAO going negative over the next week. How deeply negative they go is still up for debate. PNA still negative and I see no signs of that changing in the next couple of weeks. I think the SE ridge retrogrades to Texas / S Plains area. MJO forecasts from the GFS and Euro keep the MJO in Phase 7 thru 12/29. The Euro monthly which does go into January quite a ways is showing Phase 8 being possible after 1/10/22. Kyle MacRitchie's experimental MJO model has Phase 8 by early January and Phase 1 sometime during Week 2. If this pans out the first half of January could be very interesting. A wait and see game this far away obviously.

tpweather wrote: ↑Wed Dec 15, 2021 3:25 pm

tron777 wrote: ↑Wed Dec 15, 2021 2:02 pm Quick long term thoughts:

I am seeing more and more models showing a dual blocking structure to the North American 500 MB pattern. You've got an Alaskan ridge or -EPO that is centered a little too far west for us, but you get the arctic air dumping into Western Canada and into the Northern Rockies / Plains. We've also got a nicely placed -NAO pushing well into Greenland. However, at the same time we continue to have a robust -PNA which will keep the storms crashing into the West Coast and ridging will want to fight the cold air attacks as they come in with each storm. By the time we get towards New Year's and beyond, I think if the MJO does get into deep Phase 7 if not even Phase 8, the cold shouldn't have a problem getting down to us. I think the core of the coldest air stays NW of us which is fine. We just need 20s and 30s for snow which would work. Again patience is needed but I am really beginning to like what I see as we approach New Year's and beyond

A check of the Tellies shows the AO and NAO going negative over the next week. How deeply negative they go is still up for debate. PNA still negative and I see no signs of that changing in the next couple of weeks. I think the SE ridge retrogrades to Texas / S Plains area. MJO forecasts from the GFS and Euro keep the MJO in Phase 7 thru 12/29. The Euro monthly which does go into January quite a ways is showing Phase 8 being possible after 1/10/22. Kyle MacRitchie's experimental MJO model has Phase 8 by early January and Phase 1 sometime during Week 2. If this pans out the first half of January could be very interesting. A wait and see game this far away obviously.

Great Post Les and just to add to your post. I believe next week is a step in the correct direction to bring hopefully some decent winter weather this way. Next week is one of those 4 weeks during the winter season where you can have either rain or snow which is much better than we have seen so far this season. Even at this point some of the models are trying to bring a system in here for either Christmas Eve or Christmas Day and yes there may be enough cold air around to see snow. Again way to early for predictions but with other signs that you have stated like the AO and NAO going negative that at least gives us a fighting chance until the end of the year and yes if the mjo will head into phases 8 and 1 in January the pattern will no doubt lean towards a colder month and hopefully a white one as well. Still concerned about the southwest ridge which is really a big problem this late fall/early fall season and if that continues in January with the other tellies turning out they way the are headed that could mean some nasty ice storms and could be near us as well but again lets see how the pattern changes and go from there. I will be gone from Dec 26th until Jan 2 but I hope there is some snow during that time period locally but please save the bigger storms until the 3rd of Jan lol.

tron777 wrote: ↑Wed Dec 15, 2021 5:03 pm The wind has diminished for us locally for now anyway and it's nice outside right now. Tunes, cold beer and the grill is going here. Baked potatoes and eventually some prime rib steaks are on the menu.