I’ll discount any Op model that has wild swings in a time period run to run and the GFS past 5-7 days does that all the time and yes a I feel the same about the op EURO.
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Pattern February 2024
- Thread starter SD
- Start date
Cary_Snow95
Member
Super isolated Deep South storms snowing in the 38-40 degree range. It can certainly happen but I think we’d all be more comfortable if the setups being shown were anchored in place with a true arctic high
ATLwxfan
Member
With garbage setups. Dynamic cooling and lows making their own cold is a frivolity in the south.
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Hasn’t the GFS been showing hits though ? Like the big hit last night in SC/GA/N FL ? I mean that’s pretty far south that’s pretty telling
griteater
Member
You know, this kind of hit me earlier today as I was watching a model run.
One of the key rules with wave breaking within jet streams is that if the jet is running more poleward (farther north), it's more likely that the waves are going to break anticyclonically (rollover to the right at the top of the ridge)...while when the jet is running more equatorward (farther south), it's more likely that the waves are going to break cyclonically.
La Nina is associated with more poleward jets / more anticyclonic wave breaking (on average) / El Nino is associated with more equatorward jets / more cyclonic wave breaking (on avg, especially later in winter). So, we can see a good example of that now in the North Pacific. What this means is, as that ridge climbs up into AK, it's less likely to break anticyclonically, which is what you would want to see to get more cold air sent south. Now, I'm not saying that we can't get cold air sent south, but those are some ideas associated with the setup here. Some of the model runs do have some level of anticyclonic wave breaking atop that ridge, but not in a bold way. Also, you could have a ridge-bridge type deal where the AK ridge runs head on into the Greenland Blocking ridge and that could dislodge some cold as well. So, we'll probably need to rely more on the setup of the Greenland Block / 50/50 low / Surface High Pressure over the Great Lakes to deliver the cold south.
This concept of anticyclonic and cyclonic wave breaking makes me think of some other related things:
1. On that first image I posted, you can see how La Nina-like anticyclonic wave breaking over Alaska could easily lead to a -PNA pattern. In contrast, you can see how the El Nino-like cyclonic wave breaking in the Pacific leads to waves breaking off the Aleutian Low and them tracking east into California and Baja, while also leading to western ridges that rise up the U.S. and Canada coastline (negative tilt)
2. On the Atlantic side, you can see how cyclonic wave breaking is preferred for the development of -NAO because after the ridges climb north, they will then move west, feeding into the development of the Greenland block
Seems slightly different 
Flotown
Member
seen elsewhere that euro control looked very interesting next week..fwiw
TNweathergurl62
Member
I would really love to see our friends in the Carolina’s get a big dump of snow. Not sure how we got 8 inches of the fluffy stuff. It was fun but you all deserve a good Snow! Keeping my fingers crossed for you all. We have been enjoying the 50’s and 60’s. Ready to get my flowers going here in Middle TN. ????????
Nomanslandva
Member
Honestly, it's got to be inside day 4 before I am even thinking there is a chance. Given euro is south, there is a chance, but I really don't trust any models at this point much beyond day 3 and even then, you have to be on the right side of the drift.
Especially with ridging over Alaska. The GFS operational runs are determined to break it down.
You would think that the EPO going negative and the MJO moving into phase 8 that the ridging would have a tendency to hold on like the ensembles are showing. I seem to remember that in January 2022, the GFS was being much too quick to break that ridging down but it held on through the first part of February.
It running right now… I’m only 42 hours in
Solid. Bring the northern stream through, trail the southern wave behind it, take your chances on cold enough being deposited 
Sucks it really has no vortex in the NE and any WC ridging got demolished the initial trends were good
Brent
Member
From the NWS here
Uncertainty continues for the weekend forecast and the eventual
passage of upper level system. There remains some guidance that
would suggests a possible transition to winter weather as the
system departs Sunday night or early Monday morning, however given
the lack of antecedent cold air and the lingering inconsistencies
in model solutions and large ensemble spread, will keep any
mention of snow out of the forecast at this time.
Uncertainty continues for the weekend forecast and the eventual
passage of upper level system. There remains some guidance that
would suggests a possible transition to winter weather as the
system departs Sunday night or early Monday morning, however given
the lack of antecedent cold air and the lingering inconsistencies
in model solutions and large ensemble spread, will keep any
mention of snow out of the forecast at this time.
