Absolute Vorticity

For this weekend, we look to be dry with temps in the mid 40s Sat, and the 50s Sun. U40s to L50s for early next week. Models diverge with regards to precip after that. Still a good signal for a bigger system around the 8th or so as well.

12Z Euro today had a nice overrunning event for snow lovers around the 11-12th. Obviously that'll change. However, if you saw BG's video today, by the 2nd week of Feb a stalled out boundary will be in the region. We want it to our south so we can get snow versus rain. It'll be an interesting pattern if the high to the north can press down the SE Ridge just enough.

First week snow chances for the lower 48

Bgoney wrote: ↑Thu Jan 30, 2025 8:09 am First week snow chances for the lower 48



IMG_3131.png

Not good for week 1. For Weeks 2 and 3 that map should be improving with time. For us locally, I like the period from around the 10th thru 2/14, We should have an overrunning event occur during that window. Hopefully, we'll be on the correct side of the boundary.

tron777 wrote: ↑Thu Jan 30, 2025 8:14 am

Bgoney wrote: ↑Thu Jan 30, 2025 8:09 am First week snow chances for the lower 48



IMG_3131.png

Not good for week 1. For Weeks 2 and 3 that map should be improving with time. For us locally, I like the period from around the 10th thru 2/14, We should have an overrunning event occur during that window. Hopefully, we'll be on the correct side of the boundary.

Great Post. Next the NAO is going to be positive and this means the flow should be rather quick. For us normally in this pattern we are mainly rain for precip type. The AO which starts out slightly positive is expected to head towards neutral and this tells me a portion of the polar vortex is once again trying to stretch out. How far south is the question and that also helps to determine where a boundary will set up. The southeast ridge looks to be getting a tad stronger and this also is in the equation where a boundary will set up. The pna should remain slightly positive which it has for the most part all winter long so this does help a tad in keeping a longer warm spell happening.

Snow pack and yes that is going to be getting less and less for many folks and when you have no snow cover to the west milder air can no doubt override cooler air unless you get enough push from the PV. So what happens after next week and again I am just in a holding pattern at the moment but next week I believe is going to be busy and again model runs will vary more so than normal so yes one day a nice snow storm and the next run we are sunny and 55.

I agree Tim.... models are struggling with the individual features. What looks to be known is a stalled out frontal boundary. Its location, strength of each wave moving along it, as well as the cold air pressing in from the north are all unknowns at this time for the period in question. I expect rain with the next couple of systems but after that, wintry action is certainly in play.

I dont think anything (reasons)has changed for me from Les’s opening thread post for the first half of Feb.
Midwest and Ohio river cutters for that time period with the cold shots coming after low/frontal passage

Bgoney wrote: ↑Thu Jan 30, 2025 12:23 pm I dont think anything (reasons)has changed for me from Les’s opening thread post for the first half of Feb.
Midwest and Ohio river cutters for that time period with the cold shots coming after low/frontal passage

Agreed... we look to have rainers for the 1st week of the new month. Better chances for wintry precip come Weeks 2 and 3.

12Z Guidance echoes the above (including ensembles) very well today!