Stormchaserchuck1

Tapered back to flurries here. Line gaining some strength in western Va. Short term models have it intensifying about 10am.

Big time -AO on 0z GFS ensembles hr96-300. probably <-2 std. 180-192hr to me looks like big ice somewhere as there is arctic blocking/ridging, and the PV underneath of it near the Hudson Bay and SE Canada, then a ridge riding over it in the Mid-Atlantic from south-based+NAO. -AO's are our best index pattern for snow though, so it's possible it's snow north of DC/Balt in the normal climate zones and ice south.. still way far ways out.. it can go either way but with a <-2 AO less chance it's rain, imo. See if that part holds.

It started actually at a pretty good rate. Very lite dusting on things right now.

Light snow has started here!

I'm under moderate greens and still nothing here, radar looks healthy though. I'm hoping for 1"

9z RAP is a major hit for Sunday

Yeah.. I mean they are big misses

12z Hrr and NAM want nothing to do with the 2nd system

Whoa! 2-3" snow depth tomorrow between Westminster and Hagerstown on the 12z NAM

12z Hrr has a pretty good band coming through 12z-16z tomorrow. Has up to 1" snow depth near the MD/PA line.

Yeah, that and the ridge over Alaska and the Bering Strait is why there's so much strong arctic High pressure to the north. I would love for this to hold. In the last 20 years a heavy qpf storm with really strong High pressure over the great lakes or southern Canada has been really rare.

9z RAP actually has a nice little burst 11am-12pm Sat

+NAO/-WPO/-EPO's can be icy. A strong High holds in southern Canada for a parade of storms on this run of gfs.

Well here's this storm.. we have a 1030mb High over the Great Lakes. +NAO is bringing the jet stream a little north though

6z GFS is a little bit of a hit.

Man does this cold air intrusion look good.. let's see if following waves down the line make it to snow.

+0.5 correlation is one side more than another, so 75/100 overall. 0.0 correlation is 50/100. I'm talking about % chance of an outcome. That makes +0.25 correlation 62.5/100 overall. -0.5 correlation would be 25/100. I use the CDC linear correlation maps as a base, and they use all data, positive and negative, 1948-2020.

Believe it or not though, the 3 lowest PDO's on record for the preceding Summer or Fall were all cold following Dec-Jan's in the Northeast (1955-6, 2024-5, 2025-6).

It's kind of hard to explain the 1980s cold phase otherwise. We have seen, on record, 5 swings between positive and negative, each spanning about the same amount of time. I think recent +AMO in comparison to global SSTA does look about even though. In 2023 and 2024 the Atlantic was warmest on record, and that fit a typical std a the peak of an AMO cycle. Would I say that the 2030s and 2040s will probably be -AMO, or cold Atlantic SSTA? lol, probably not. But I do think it could come down to near average for a few decades, or at least stop breaking records. That's one thing I honestly have to read more up on.

Well -NAO's are happening much more frequently during, or after, Solar Min's than Solar Maxes. We had a Solar Max until Summer 2025, so there is actually a 0 to +4 year lag after Solar Max for cold season +NAO (0.25 correlation, or 62.5% of the time), and a 0 to +4 year lag after Solar Min for cold season -NAO (0.25 correlation, or 62.5% of the time). The lag after Solar Cycle has us in +NAO probability until Summer 2029.

In January 2024 we got some snow events when the NAO went negative. In stronger El Nino's with a big low pressure in the N. Pacific, a -NAO could be the difference between nothing and a big one. I just don't think we are there with the NAO yet at least consistently, maybe in 5-10 years..

Lowest Winter DJFM NAO since 10-11 was -0.24 mean. 13/14 years positive. 19/19 months of >1.11 all positive. We just need to break that. I think it's somewhat decadal.

In the Summer I was seeing that really cold 500mb 60-90N and negative SLP (large -8 anomaly over the whole arctic circle June to August) -- I was seeing that these things strongly preceded -AO Winter's. It was a really strong signal, like the plus and minus side has hit every time since 2012. So I was bullish on this Winter for thinking it would be mostly -AO. You know -AO is our best snow pattern. It is turning out to be more of a -AO Winter, but the STJ has been dry up to this point. It does look like after Jan 21/22, it will get wetter. I'm not ready to say this Winter one side of a fail coin, because I think there is high potential Jan 23 - Feb 10. We might even do average snowfall by then. 384hr long range ensembles are showing an east+PNA, which you know correlates with our greatest snowfalls. Let's see how that 3 week period mid-Winter does, even if models aren't showing much right now. Besides that, the lowest Baltimore's average high goes to is 38F on Jan 27, and DC has an average high at the lowest point of 40F. average x average is still not good enough. So we can fail on both sides, if more extremes aren't being met. Our last -PDO was with -NAO, this one is very +NAO. Kind of a big difference for coastal SLP. I would like to see a west-based El Nino like 02-03 or a El Nino/-QBO like 09-10.. now 23-24 was El Nino/-QBO but it was very -PDO and an east based event. east-based El Nino's and -PDO are actually the warmest Winters for the CONUS since 1950.

I'm a little scared that if we do an El Nino next year it will be warm. These last 2 cold Winters, 24-25 and 25-26, are not because of a -NAO decadal, or +PDO decadal. They are negative AAM tendency propagating toward the Pole. Sometimes that happens in La Nina's, especially well into a decadal state of many events. Recent El Nino's have shown a tendency to warm SE Canada, as 7/8 (after this year 7/9) recent +WPO Winter's comes into effect. If we were well into the cold-phase NAO I would feel better, but we are not, and there is a +0-4 year lag after a Solar Max for more +NAO conditions. -PDO, if that holds, -PDO and El Nino is also a warm composite.

6z GFS a miss 2" for Richmond - Va beach