psuhoffman

It won’t last long with that look up top, especially as we head later in winter.

@Bob Chill gefs would just need another 48 hours. That epo ridge among with the developing -AO would beat down the SE ridge. I don’t care if that takes 17 days v 14 days so long as that’s real I’m happy. It’s still early January. I said a week ago when the disgusting look showed up that if it locked in more than 2 weeks or so that puts us into really ugly analog territory and we wanted to be able to see the “other side” by mid January. It’s only the 8th and the other side might be showing. That’s totally fine by me.

This is the euro mjo from a week ago It simply wasn’t going out far enough to get to where it is now. 4 days ago it was getting it into 6, not quite as far as yesterday but the difference was marginal and not close to the definitive trend towards 8 you are making it. You are taking some pretty big liberties to say “guidance is trending towards cold phases”. The last wave did not make it into phases 8/1. Before that we had a standing wave in 2/3. The euro does often tend to kill waves early. That is a bias I’ve noticed. The gfs looked even worse though. Somehow you don’t even post or mention that! There is also disagreement among experts. Some think this will progress into the pac and others are nervous about a stall in the MC. I am open to all options because the final outcome falls outside our high probability forecast range. I am happy for you that you feel as confident as you do in how everything will play out I don’t ever have that level of confidence in the mjo or anything else at 2+ weeks lead time. You also keep misinterpreting analysis as forecast. When I say “if we don’t get an epo ridge or the NAM state to change we’re screwed” that isn’t “he said we’re screwed”. I said we need to look for either the epo or NAM state to flip because we need one of those 2 factors to change. Yes if neither does then we ARE screwed. But you jump past the “if” and “or” and derive a definitive forecast instead of seeing the analysis of permutations. For the last 10 days the cpc pattern analogs have been dominated by some awful years. 1952, 1989, 2002, 2008 for example have all littered the top pattern comps day after day. You can think that’s no big deal if you want. And there are examples of comps that flipped better also and I presented those as well but they were the minority. But I also pointed out the bad years were mostly Nina’s and this is not. I gave both the good and bad options, and the bad ones outnumbered the good. That’s not my fault it’s just reality. Maybe we beat the odds this year. But the numbers are what they are. I presented what the current projected look lead to in past examples. It wasn’t good most of the time. If you have an issue with that sorry. My style is to present what could to right AND what could go wrong. I look at the fail scenarios and what to look out for. But I’m not a pessimist. I’ve often been bullish on snow chances when it’s warrented. I was bullish on this winter a month ago. I’ve been bullish on a big storm look from long range before. But only when there are legitimate good signs. I don’t blow smoke. If you only want to hear what could go right there are plenty of people that will make you feel warm and fuzzy no matter what the pattern is like JB.

That’s pretty much what I was saying my fear wrt where the eps look could evolve if we don’t get epo help with a strong +AO but it doesn’t have to go that way. But I would feel better if we got some indication forcing would change in the pac.

End?

I’m trying to be optimistic about the eps. But the danger if the NAM stays super positive and pac ridge relaxes but stays centered too far southwest once a trough pulls back into near AK ( which it would when the pac ridge relaxes) we would just transition to a zonal pac puke pattern. If we want a stable better pattern we either need AO/NAO help or an epo ridge. Absent either of those were rooting for luck with a perfectly timed transient feature like today. A ridge traverses the pna domain at the exact perfect time but even so it’s got limited potential and some will fail because of the overlying crap pattern. Who knows maybe we keep lucking our way to a decent year in an overall craptastic pattern but I don’t want to have to roll that way if we can avoid it.

It’s a convoluted look that has to be the result of higher than normal divergence. But there are features to like. The pac ridge relax and pressing into the west coast. Hints of a southern stream. Ridging west of Hudson. Still things not to like, the NAM. My take is the eps is unsure where to go which is better than some other options.

Know your climo, we spend 90% of our winter periods in “screwed”. It’s what we do best.

The GEFS is even stronger into Phase 5/6 than the euro, but worse it starts to loop the wave back through warm phases with high amplitude in the long range. The euro simply kills the wave and lets "other factors" take the wheel. If the GEFS is actually right and the MJO stays in high amplitude and does a loopty loop in phases 4-6 were screwed. Lucky the GEFS been getting schooled by the EPS for a while now. Of course with our luck this will be the time the GEFS nails it.

Depends what you consider “long term”. Most of the top analogs did lock in a long time. But there is no way I could pour through every week of every winter. I did look at every January. But a 10 day period can be masked within the monthly mean. But if the pattern locks in enough to show strongly on the monthly composite then no...all those examples it took blocking. Then there is this...since others have mentioned 1993 There are some significant differences in the pac near Hawaii and the location of the ridge so it didn’t show up as an analog but it’s similar in some ways. That year improved without blocking. But the snowy February was NW of the mid atl cities. And the one March storm was a crazy anomaly. A repeat of that pattern would be better but might not really make DC people happy. But it did get more of a trough in the east without blocking. But it wasn’t as good a match. So there is the issue of degrees. What is better? What is a good enough analog to include in the dataset. But a few things are clear from the analogs. 1. It’s a bad pattern. 2. It can last a long time (not always but it can) 3. If it locks in long enough to dominate a monthly mean it’s very likely to continue. 4. If it does without blocking were toast. That is all true but it leaves escape hatches. Maybe the pattern only lasts 10-15 days. If the pac ridge weakens or shifts into an epo ridge that opens non blocking options that might have not shown up. Or maybe we get blocking later in winter.

Yes but with the caveat that the pac ridge locked in for more than a short period. That feature is really starting to rage now but if the eps is right and it starts to wane in 12 days or so that takes us out of dire straights territory. If the eps long range is correct the January monthly mean won’t look like the bad composites as much. But if the pac ridge stays dominant then yes we would need blocking to offset. There are no good looks with a strong central pac ridge and a +AO/NAO Its still way out there though. And we would be better with blocking. The gradient pattern the cfs and eps is advertising can easily end up with most of the snow to our northwest if we don’t get lucky. Hate to say it but that look isn’t so good for your area. You would likely need more help. But it’s still a way better look than the raging pac ridge western trough combo.

It was a good run. Ejected the vortex away from AK which was my main gripe with 0z and built ridging into epo. First legit good run in a while. I was just kidding about Ji taking a 4 week hiatus.

Dude it almost worked.

Check back in 4 weeks!

That’s the best look we’ve seen. 12z Gefs is hot garbage. No way to spin it it’s at least 10 days away from good at day 16 and not even heading the right way. The geps is an ok pattern. Problem with the eps last night it had too much trough near AK. With the pac ridge. AK trough and no block it would transition us right back into a pac puke pattern. We would trade a SE ridge for pac puke zonal pattern. No thanks.

This...we have been in a pac puke pattern from an AK vortex. That isn’t good for the pac NW either. It’s also not good for us. Right now we are in a temporary flux between patterns and that’s why we have a shot as a minor snowfall tomorrow. But the coming pattern is good for the west bad for us. But the pac coast needs an anomaly to get snow even in a good pattern.

I know you aren't saying its "good" just better...but my fear with that look is that even if we got a colder shot as the trough slides east...with that look in the PAC, along with the EPO/AO/NAO it would be extremely short lived and unlikely to include much snow. IMO that pattern rolled forward the CONUS is about to get blasted by pacific air again like before xmas. What is left of the western trough would roll through and then we would go zonal. A week after that pot I would suspect we would see a big blue ball up top and a ring or red around it across the mid latitudes. Very 2002 like...that is how that year evolved. We are seeing a singular point in time at day 15 which looks "better" but I don't think that look is heading anywhere positive for snow opportunities. Maybe "better" than the absolutely worst look imaginable we will be in for about a week before that...but if we were in anything close to a decent pattern now looking at that in the long ranges we would be pretty upset about that look. ETA: ironically even though the GFS looks like a hot mess on wheels at day 16, its evolving the pattern in a direction that at least has a fraction more hope/possibility beyond that time period.

I have flat out said it so people can hate on me if they want...but if we get to Jan 15 or so and we are still looking at what we are looking at now...then yea I agree with that. I showed how this currently pattern in January...more than 50% of the time can persist all winter. But the minority of years where this pattern in January did flip better in February the signs of that were showing up well before February. In all of those examples by the last week of January the pattern was in transition. If we get to the point where we can see to February and it still looks like utter crap with a central pac ridge and +AO we are entering territory where no previous example turned out good. We aren't there YET... still another 10 days or so to see real improvements before we are to that point, but the clock is ticking.

No I think there is a possibility someone in our forum gets a small event (depending on your standards, Ji and Mdecoy should probably ignore it though). But even if DC manages a nice 2" event Tuesday the idea of reaching climo for winter is still in some jeopardy given the pattern look we are seeing. But even most of our really bad years had some snow at some point. When I say things don't look good I usually mean wrt to climo not that we won't get any snow at all.

GEFS looks like crap long range BUT at the very very end its showing a way out. The NAM seems to be flipping and we are one good wave break (maybe from a cutter) from getting the atlantic ridging to build over the top and link up with the Pac ridge...and that is when that western trough will broaden and come east. You can see it starting to move east at the very end in response to the changes up top. Now taking the day 16 GEFS is silly...just saying it is on its way to a better place by February IF that look is right. Thats all. BTW, just to clarify what the purpose of my pattern posts was. I am NOT saying there is no hope. I didn't even make a real forecast...I made a seasonal one and if those pattern analogs are right it will bust. I don't really make day 20 forecasts...thats silly. I was just posting the analogs to what we are looking at and showing what the past indicates the likely outcomes are. And yea, historically most of them turned into pretty bad winters. But some did not. I am rooting for the "some that turned out ok". But the numbers are what the numbers are, not a forecast, just a "this is what happened in the past when we had a similar pattern in January". It is not what I am saying will happen or what I am rooting for. But given the reality of the past results I have tempered my own expectations so that I am not frustrated everyday when things don't suddenly look like a winter wonderland on guidance. If we get a 1960 or 2006 type pattern flip GREAT and I will be even more excited given my current low expectations. BTW we can probably include 2007 in that flip category. It didn't work out great for us but we did get some snow AND the pattern was great in Feb 2007 even if the results left a lot to be desired. As I pointed out in the climo thread...luck has as much to do with our results as pattern sometimes.

The discussion you replied to was comparing the gfs and gefs. The implication of what you said was clear.

They are exactly as useful as they were a year ago when they were still linked to the old gfs op. They didn’t degrade somehow they just haven’t progressed. The new gefs will no doubt be an upgrade. But I guarantee you the current gefs is vastly superior at very long leads to relying on a single operational run. Of ANY model

Day 10 op euro would actually set up a good pattern day 11-15. Builds enough of a ridge bridge to suppress the pattern get the boundary near us. A little more HL blocking and this is suddenly a really good look. We need to see the ensembles start to go this way though. So far just an op run at range

Sure but I am not going to spend as much time studying our fail patterns as I did our winning ones. I just don't hate myself that much. But I know off the top of my head what years and patterns really suck balls and put together a quick profile of some of the worst ones. First of all... while we can score a fluke snowfall in many patterns...the truth is there are way more looks that just don't work out often then there are ones that do. We are south of the mean northern stream jet in winter most of the time. It takes an anomalous pattern to get snowfall. The warm wet cold dry thing is real. Often in winter the only time the cold boundary gets south of us is after a wave passes and the flow behind it presses the boundary south. But without a favorable pattern the return flow ahead of the next wave is likely to press the boundary back to our north before it gets here. Basically the average storm track is to our north. But most patterns with some luck and some bootleg factor (like a Hudson ridge) working for us we can occasionally get snow. But most patterns without luck we can easily go with no snow as well. Bad Luck On top of that...sometimes we can just get unlucky in a perfect pattern. A storm gets suppressed, the next one is just slightly too warm, another develops off the coast...next thing you know we wasted a 2 week perfect pattern. The winter of 2007 would fall into that category. Look at this H5 pattern for Feb March was pretty good also for a good portion of it. THe first half was pretty crappy and I will use December 2006 as an example of a crap look later but even with a wasted Dec into Jan if you told me that would be our look for Feb and Mar I would take my chances. ANd while we did get some snow...we didn't cash in on the full potential and so the winter went down as a below avg snowfall year. There were 2 blockbuster coastals that year...one in Feb and one in Mar and both were just SLIGHTLY too warm at the mid levels and the big snowfall ended up a little NW of us. THere was one storm that had big potential but a PV lobe at the wrong time squashed it. And a couple others just failed to reach potential and ended up minor snowfalls. We mostly wasted a really good pattern. That has happened other times as well. On top of that, even more common, we waste a look that is OK, not great but definitely not awful and end up with a really bad result. YOu can look at the H5 for a year like 1981 and say...that looks ok. Not epic but you wouldn't think a horrible dud winter was coming, but it was. Truth is snow here is anomalous and luck wrt timing and discreet features that fall under the pattern level have a LOT to do with our results. Call it luck or chaos but pattern is only half the fight. So all that said I will focus on a couple patterns that just really really really suck and give us almost no chance for a significant snowfall, luck be damned. Some general observations First of all, any pattern that features a +NAM state without either a perfectly placed east based EPO ridge...or a really favorable PNA ridge is a fail pattern. We can score in a +NAM pattern but only with pacific help. If the AO/NAO are both awful (like right now) and the pacific inst in a very favorable state...that is a total fail pattern. That is because anything that pumps a SE ridge without resistance up top will not end well here. Additionally there is seasonal variance. The NAO is way more important later in the season. As the temperature profile tends to get colder across N. Amer later in the season and wavelengths start to shorten in Feb, and water temperatures cool along the coast, blocking on the atlantic side can influence and overcome the pacific pattern more. Early in the season we really need pacific help to have a good chance. But bad looks can be very temporary or transient so what patterns tend to give us that and lock in for an extended period of time. I assume that is what you mean because we can have a bad week even in the best winters...but what looks spell doom for a really long time and eat up a big chunk of our winter window. AK Vortex Pattern The first is an AK vortex pattern. This one is especially a killer early in the season. It can be overcome from Mid Jan onward but only with NAO blocking. Early it tends to be a problem even with blocking. Without blocking this look is a total fail pattern all winter long. You pointed out earlier that 2012 was a good example. December 2006 was also a perfect example. The last 10 days also featured this problem. I have the h5 below...the issue with this pattern is the flow under the AK vortex floods the continent with warm pac air. Without ideal blocking on the NAO side that mild air will flood across and not only will we be warm but there won't be any cold air anywhere near us. This pattern can take a LONG time to recover from. Even once the pattern improves we can waste a week just getting cold back onto our side of the hemisphere. Dec 2006 January 2012 Last week... Pac Ridge +NAM pattern The next one is the one we are about to go into according to all guidance. How long it lasts is yet unknown...but this is the absolute worst pattern we can possibly ever get into in winter, both because of how bad it can be...numerous examples of completely snowless months with this pattern...but also because of how stubborn it can be. Frankly this is the most common season destroyer of all the patterns. This one accounts for the majority of our total fail winters. This is the composite of many of our total fail years that fit this description, the Jan/Feb of 1950, 1951, 1959, 1973, 1989, 1990, 2002, 2008, 2013. All of these were single digit snowfall years at BWI except 1990 but all the snow fell that year BEFORE the pattern set in early January. look familiar? This one is real simple...that pac ridge digs the trough out west...which pumps the ridge in the east. Simple wave physics. Without extreme blocking to offer resistance that will push the thermal boundary well to our north. The reason this pattern can be so stubborn is an anomalous central pac ridge is usually a primary effect not a secondary effect. Meaning usually it is being driven by the tropical pattern in the central pacific and Maritime Continent regions. It's not a result of something that caused something that caused something...and so on. It is the direct result of a very major driver of the global pattern. IF that driver doesn't change...that ridge can park there for months. And that ridge loads a wave pattern over north america that sucks for us. It can only be overcome with extremely -NAM state to suppress the SE ridge. Too much of a good thing The last one I will cover that has accounted for some total crap years is the "too much of a good thing" pattern. I almost didn;t include this one as its a weird anomaly. This one is rare, usually only happening during a super nino. And if you just glance at the h5 it doesn't look that bad. And...it does increase the potential of a blockbuster storm. We had this pattern a few times and sometimes we get lucky and time up just enough cold to get a HECS. But if we dont....we can go long stretches simply too mild to get snow. The best examples are 1983 and 1998. Yea we had the HECS in 1983 but imagine if that one storm had not hit. The rest of the prime part of that winter was a total wasteland. Basically like 1998. The issue is hard to see just from h5 but its kinda there. The super nino. That pac trough is actually a bit much...if it was a little less anomalous and near the Aleutians not so expansive it would be perfect, and that is the typical moderate nino look. But in this case that extreme trough in the pac is flooding the CONUS with mile air. THe trough over the gulf is the juiced up STJ but the flow under the pac trough combined with the ridging across the US/Can border has flooded the US with mild air and cut off any cross polar flow to press cold into the pattern. The result is just a mild pattern with a good storm track that yields cold rain. It's not a mild look. Just not cold enough to snow. Pretty miserable really. This one suck but its not that common so I wouldn't worry too much. Plus it gives us the best chance of all the fail patterns at a fluke storm, and a BIG one at that. But since 1998 was one of our worst winters I figured I would throw in an explanation of why. There are other fail patterns...pretty much any look with a SE ridge and no blocking... but those first 2 are the main ones that can last a long time and wreck months or even a whole season. If anyone wants to add more great but I am depressed enough now so have a good night. Hope this was what you were looking for.

Pretty good