Stormchaserchuck1

New CPC 3-4 week has below average temps and above average precip for the coldest time of the year. I was thinking a -PNA would start to get going at that time, as the La Nina is really strengthening right now, but that's not what these maps show..

0z Hrr has 1" for me.. a nice 5-6 hour snowfall.

Hopefully I'm not too late. January 2025 DCA _ NYC _ BOS __ ORD _ ATL _ IAH __ DEN _ PHX _ SEA -5.3 -4.4 -3.6 -7 -5 0 +5.7 +6.2 +4.2

Seems like you guys forgot the first one is still 7 days out lol

Watch this timing.. it's not going to phase here, but it could on future runs with some slight adjustments.. lots of potential showing on todays models around Day 10.

I feel like a more probable trend going forward is to juice this thing up a little, vs stringing it out like before. Energy seems to be consolidating on a main vort.

Some similarities to Dec 18, 2009 in the NAO and 50/50 low region Although we did have a low in the gulf and El Nino STJ.. it was leading a colder wintery pattern to follow though, I like that similarity. H5 is pretty close over North America and the Atlantic.

blizzard map

On 0z GFS ensembles, mid atlantic is below average at 500mb every frame from 24hr to 384hr

I don't think rain will be an issue for Jan 6th.. upper latitude pattern is too favorable for cold. Question is does the storm get sheared out or not. LR GFS ensembles look good still at 384hr! No signs of -PNA that it seemed to be trending toward at the end last night, -EPO, sustained -NAO, West coast ridge.. -AO is going really strong 6-10 day shows the CPC thinks this coming storm has a chance..

Models are trying to handle the continuously building -NAO.. they may be a little too dry right now, just doing what the index typically favors from the medium range. I love that 50/50 low.

Yeah, that's what I like to see. Look at that 50/50 Low. This storm actually has a lot of upside potential NE of DC.

PNA has been positive every day this Winter so far (since Dec 1), and it looks to stay that way through Jan 15th, with nothing lower than +0.5 being modeled.

We haven't had much upper latitude support for the last 8 years.. maybe a handful of months honestly. NAO has been positive 41/46 Winter months since 2013. RNA broke it's 7-year consecutive record by 175% (going back to 1948). Now the GFS is showing >+400dm -NAO for the next 15 days. I'm stressing this because the global pattern is more consistent than when models just show a trough over the area. Last year and the last few years it would show a trough and snow when we were in -PNA! It's different this time, meaning it would take a much greater shift to erase the "cold enough for snow" pattern that right now has global support. My only fear is that the -NAO is being over modeled. But it's pretty legit. If we get waves, some should be snow. Of course too, +PNA/-NAO correlates with dry, so it's nice to see an active pattern on these models. I'd rather them show several waves cutters right now with a major -NAO block being modeled and no -PNA.

Individual ensemble members all over the place, but I'm surprised how many show cutters.. it's not an unfavorable upper latitude pattern. Maybe just be happy that they are showing so many storms in the medium range!

Thanks! I did better than I thought I would this month. Looks like you did pretty good too.

0z GEFS holds the -EPO, which is the colder solution.. https://ibb.co/Xy73Yf1

The Day 11-13 storm? Pacific is trending not as cold, a few days ago it was pretty different actually with strong -EPO/+PNA, now it's just a weak pattern on the models. A weaker pattern actually allows things to cut, but we could be looking at upper 20s snow vs 10s it was showing before. I think it will be an interesting bit of time here tracking it all.

This one has a perfect 50/50 low. Historical maps of our best snowfalls have the 50/50 low area almost as low of an anomaly as the actual storm (meaning it is super important)! I'd definitely watch NE of DC.

Really strong -NAO through Day 15 on todays 0z GFS.. The Pacific ridge is trying to retrograde at the end, but it looks like an active pattern under Polar ridging Usually -NAO's aren't so wet but they've acted differently for the last 11-12 years, with less suppression..

It's going to be hard for it to cut into a -NAO block. The Pacific isn't unfavorable.. I think the key is how cold it gets before hand. The pattern is still raging +NAO/+EPO right now so we'll have to see how this pattern change over the next few days goes. Worst case scenario, the -NAO is not as strong as currently projected.. Edit: We do already have -NAO today, I was a day or two ago. So the pattern change is already taking place.. gives more confidence to the solution. The H5 does let up a little during the storm, any trend towards a continuum is good, we have a good pattern on the front and back end.

I still like the Jan 6th storm. It has a ton of moisture in the Midwest, moving into a -NAO block and 50/50 low. Very unlikely it will split off in pieces like the GFS is showing, there will probably be at least a 1-2 day space between waves, or it may organize as the front end storm completely. In which case, it could be a decent thump of snow with the moisture Jan 5-6. Not really a strong -EPO pattern yet on Jan 5/6, which is usually associated with a lot of ice. 7-8 days to go. A lot will be worked out. I love snow that precedes colder periods. These have been more rare lately.

I had a lot of roll forward stuff that was showing a warm Winter. It was interesting when the Southern Hemisphere AAO hit -5 and had a record breaking streak of 3 weeks of -AAO from Aug-Sept. That S. Hemisphere factor rolled forward to a -AO Dec/Jan at a 0.35 correlation. Sometimes the methods just become too stale in a changing system.. after 8 years of the same, indexes like the PDO become a strong state, but all they are doing is reflecting the atmospheric conditions. They hit on consistency really hard, but when change comes something like all the roll forward N. Hemisphere indexes will miss it. They will be 7/7, until they are 7/8. That's why it's sometimes important to go beyond the very basic area of atmospheric circulation that is occurring in a closed system (northern hemisphere). Changes in the Sun this year could also possibly be a factor of why it went colder, I was talking earlier in the year about how we had a -H5 over Greenland 9 times this year, when we saw that pattern something like a total of 3 times in the last 4 years.

0z GFS ensembles further SW than the OP with Jan 6 storm threat. We have a good 50/50 low for this

I would say in the upper latitudes it's trending better for Jan 6th though on the GFS https://ibb.co/rpfk5jg