psuhoffman

Now that’s bad.

So no guesses on the storms?

Wrt the mjo and pattern...that doesn’t mean things can’t flip...but that when we do see major pattern flips it’s not purely because of the Mjo. An example is 2017/18. We had a cold phase rotation earlier that didn’t do us much good but when it rotated into cold phases again later as the permanent NAM state was flipping it had the canonical response. But that pattern then went on to persist even as the mjo wave faded and went into warmer phases. We need an actual atmospheric base state change along with the mjo. An mjo wave temporarily traversing cold phases during an unfavorable global base state pattern won’t do much good imo. Those kinds of pattern flips can happen. But the most likely time is late. The Nina like pac response favors such. Think 1999, 2009, 2017, 2018. Not all do but many years with similar pac issues feature a legit pattern change for March. and before the “that’s too late” posts yes yes I know. I’m not saying I want that. Just saying that’s what might happen.

I’ve had a thought on the MJO for a while that I’ve mentioned a few times as to why we often don’t get the response we need when it goes into “cold phases”. The whole “MJO phase 8 is great...except when it goes into 8” thing. Basically I’ve theorized that the main reason the mjo phase 8/1/2 are correlated with the H5 look we want and cold is that those mjo phases are also correlated too and amplified by the types of global patterns that produce those results. So basically a winter here with a cold base state is likely to spend more time in cold mjo phases skewing those phases that way. But when we have a warm base state winter and we wait for an mjo wave to save us it rarely does. Even when it makes it into cold phases the response is muted. It often makes things “better but not good Enough”. I suspect a cold phase mjo is not as correlated to the response we want when it happens in warm base state winters. That is probably because it’s acting alone and not associated with the typical global pattern (canonical el nino) that it is during cold winters. Instead it’s being muted by the background warm base state. On the other hand I think the same is true in cold winters. Over the years when the mjo is about to crush our dreams and JB is spinning to save his subscriptions for another month he likes to throw out examples of warm phase rotations that were cold/snowy. But they are always years like 1978 where we were in a canonical nino pattern and the base state was cold. For the same reason in a year like that the warm mjo wave is muted by the background state. When we are in a warm year and the mjo spikes into warm phases we always torch. This has just been a theory and I never bothered to research and support it. I bring this up because isotherm seems to offer scientific support for this. Isotherm From the NYC sub “Chris, and I've been ruminating on some hypotheses re: the time-lag and distorted response. One issue, in my view, is base-state resonance. Sometimes the MJO/intraseasonal signal is misaligned with the base state, and as such, when it propagates through typically conducive phases, the N HEM response may not be bonafide/favorable due to the misalignment with the background indicators. For example, 2002-03 had a much more classic AAM/GWO and hadley/walker cell structures concordant with a canonical El Nino, and thus when MJOcirculated to 8, we had a more genuine N HEM response.”

I’m just getting caught up on the thread but I think this is saying in a much more scientific way what I just said more observationally.

The mjo in phase 8/1/2 is great...except when it actually goes in any of those phases...then it sucks. I have a thought...not even a theory yet since all I’ve done is kick it around in my head, but it seems to me over the years that when the tropical base state is good...then strong mjo waves in cold phases correlate well. But when we are in years where the base state is crap and we wait for the anomaly of a wave into favorable phases to come it typically doesn’t do much good and the response is muted. I am not saying the mjo is not a causation but that the reason for the strong pattern correlations might be partially due to the fact that cold years that have a pattern correlated to cold mjo phases tend to spend much more time in those cold phases. So it skews the mean. I wonder if cold phases in otherwise unfavorable winters have the same correlation. When we have had flips associated with the mjo it usually happens when a longer term overall change in the atmospheric base state is occurring, like March 2018 when a long term blocking period set in. I just don’t remember lots of instances when things were a hot mess for a long time and the mjo wave into 8 suddenly saved us. Usually it makes it “better” but not good enough. Like I said this is just a thought for now and I could be injecting perception bias here. I would have to study the data to see if there is anything too this.

Nothing you said was inappropriate

Why are you stuck on the mjo projections. This started over you comparing my analysis of the EPS to Will’s and implying they have not gotten worse for our snow chances. Neither myself or CAPE said the EPS was right. Your off on a worthless tangent because your original point was BS.

The first rule of fight club... @stormtracker can we get some old school mortal combat fatalities codes up in here?

Sorry let me clarify. The statistics for the pattern in January show we have a roughly 90% chance to end the year below normal snowfall based on past outcomes. That doesn’t mean it can’t snow at all. And hey maybe this is the 10% but right now that seems unlikely. Now below normal doesn’t mean no snow. But losing a huge chunk of prime climo to a crap pattern makes it hard to end well but we did have years like 2007 where a similar January went on to a snowier February. But the statistics were only about 50/50 about it getting any better the rest of winter. In some cases the pattern did shift but to another crappy one. I noted then that some of the crap years had a late snow in March and that might be our best chance. Wrt right now...the look day 15 can go either way. My lost earlier outlined that. But with the AK vortex there with a +NAO it will be hard to overcome. I was talking about day 10-15. I have no clue after. If the vortex shifts and an epo ridge pops like the guidance suggests then it’s a temporary problem. If it sets up shop there longer were in trouble. But I’m not going to speculate much past day 15. My guess is it’s temporary. But that still doesn’t mean we get a great pattern.

Again with the false equivalency. No one even said the EPS was right. I said it degraded the pattern for snow chances the last few runs. It did. I don’t know if it’s right. It’s 10-15 days away. That range is like reading tarot cards. But you’re using a bait and switch tactic to deflect from the fact your last claim was assanine.

Ok less extremes. Even if everything fails within the next 2 weeks we still have February and early March to score a better look and or a fluke snow. The odds of this being a good snowfall year are decreasing rapidly but that doesn’t necessarily mean we won’t get anymore snow at all. Try the middle. It’s a nice place.

I’m going to try really hard to say this respectfully but you really stretch the limits of patience. Will is in New England. He is analyzing the eps from their perspective. How did the pattern in 2001 work out around here last time? And that was with way more blocking than is likely given the current NAM state. The EPS is worse for our snow chances than it was 48 hours ago. For one there are less members with snow here. While that can be a fluke in this case it’s in coordination with unfavorable changes in the longwave pattern. You’ve made posts like this several times here and in other regions peddling false equivalencies. And I am not the first person to point it out or take issue with it. Just a word of advice...the people here aren’t as stupid as you seem to think they are.

They do. They broke the pattern down erroneously several times in years with a cold base stare. PD2 was rain in the long range and not even close because I was up at PSU and it was all rain even there on the day 10 MRF. 2014 several times guidance showed a false warm up. But there are less opportunities for that because the base state is warm most years.

Nope it’s degrading run after run as more members agree on a AK vortex with +++ NAO. It’s almost impossible to overcome that combo. The Hudson ridge is the only thing creating any slim hope.

I can understand that misconception. Let me explain how I analyze long range patterns... First of all there is a difference between macro and micro. Long range is macro...short is micro. I tend to look at things in 5 day chunks. Day 1-5 we tend to have pretty good reliability on the longwave pattern. Meso scale details can still change...but the broad pattern is pretty much known and we are analyzing specifics that might shift small scale things (those matter a LOT to snow...like where the back edge is, where banding sets up, will the track of the SLP shift 50 miles..) but are not really a longwave pattern issue. Day 6-10 the longwave pattern is somewhat known...but can shift around somewhat. Of course that means identifying specific synoptic level details within this range is risky...we can start to make educated guesses about what the small scale details MIGHT be in this range but they are open to shifts. Take this weekend storm for instance...the guidance nailed the general look from 8 or 9 days out...but exactly where the mid level winds were directed due to the exact sharpness of the ridge/trough alingment shited around about 100 miles. That shifted the potential for a thump snow from MD to central PA. That is NOT a significant shift from 8 days away! On the macro level the guidance was great. On the micro is was off 75 miles or so...but that is about as good as can be expected in this time range. We are looking for generalities here not specifics. Day 11-15...the outer edge of where we can glean any meaningful pattern clues...only looking at very macro level things...clues to the basic configuration of main pattern drivers...knowing that even that will shift around some. This is just seeing if there are any clues that some favorable features like an EPO ridge, -NAO, -AO might be likely. Any micro level details are completely impossible to tell at this range. Now how I apply my snowfall expectations to any 5 day chunk. In the last 30 years BWI has had 29 warning level (5") events during the period from December 1 to March 10th. That is when the vast majority of our snowfall happens. Odds are greatly reduced before and after. Obviously odds shift some within that window but not as drastically as outside it. That is 100 days a season or 20 5 day chunks. Over 30 years that is 600 5 day periods. That means...with 29 warning level events...the odds of a 5" snowstorm during any 5 day period from Dec 1-Mar 10 is 4.8%. That is our base state...about a 5% chance of a significant snowstorm. Using 5" as significant...I picked that because it is warning level. This is arbitrary but you get the point. So when I say things look "good" it could mean a 20% chance of a significant snow. Think about it...that is 4 times the "normal" odds of a snowstorm. That is good compared to normal. But 20% still means there is an 80% chance we do NOT get a snowstorm. Even in our absolute best looks from 10 days out...I would NEVER put our odds of a snowstorm above about 40% and even that number is reserved for the absolute best looks we have ever seen from 10 days like before the January 2016 or February 2010 storms. There is way too much at the micro level that can go wrong that you will not be able to see from that range. Plus...think about right now. This area will see "some snow" just not a snowstorm. But some places will get 1-2" tomorrow...and not far away north will get 3-6". And some places will get snow snow showers next week on the NW flow. But we are just missing a "real" snowstorm by 75 miles or so. The details that determined that could not be seen from 10 days out. The micro level details that make the difference between a snow in central PA and one here is not going to show up on a general longwave pattern look from day 10. On top of that there are other things that make recognizing a good pattern for snow different from "its gonna snow". The pattern could flat out shift from day 10-15. We know that. But even if it doesn't... not everywhere in the area will get snow. A storm could just miss...when you get missed by 50 miles that isnt bad pattern its bad luck. When the storm misses by 500 miles thats bad pattern!. Finally here are some examples of why you cannot pick out a snowstorm at long range, only identify patterns that increase our odds.... Here are two examples, one worked and one just missed us to the north with a 4-8" snowfall... This one was a 4-8" snowstorm in our area This one was a rainstorm Notice the scale is not the same for both...if you normalize the scale the key features are even more similar. But there are SLIGHT differences. This was a WAA setup in both cases with a nice 50/50 to lock in confluence to the north. But the one that worked the trough axis was SLIGHTLY further east...and the ridging in the east was slightly less...although the scale makes it look more different than it really was. Do you really think those slight differences can be picked up at day 10+? From long range both of those storms would look identical. Not until within 5 days would we see the level of details to determine that one was a 4-8" snowstorm for DC and the other was a snowstorm in PA and rain for DC. Here is an even more drastic example.... One of these was a big rainstorm nothing burger...and one of the worst depressing storms in history...and the others were all HECS snowstorms...can you tell which is the bust? Take a guess...and tell me why you think that one was rain and the other 4 were all historic snowstorms in our area? A B C D E The bottom line is those all look great....and the differences minor...and from long range the very insignificant micro level issues that caused one of those to be a nothing burger vs a historic snowstorm would not be discernible. At long range I am just looking to see if the basic pattern structure is favorable (or more favorable than the typical crappy 5% chance) for a snowstorm. The details that determine our fate come in the day 1-5 range. I hope this helps wrt how I look at and analyze patterns. Curious what your, or anyone elses guess (dont cheat and look them up) is with those storms.

Vermont still looks good overall... These ratio's can sometimes be a bit high... Rutland is in a valley and will get less than the mountains around...but that is true of almost all the towns. I would expect maybe 4-8" in Rultand...with 8-12 up near the ski resorts. But like I said its only a few miles up to Killington from town. Another option...there seems to be a consistent area of enhanced snowfall in southern Vermont just south of where you will be due to added moisture from the flow over the lakes. You could take the drive south on 7 to Manchester or Bennington. Manchester is about 30 miles or 45 mins (in good weather) south of Rutland. I know there are some shops and restaurants in Manchester. I haven't spent a lot of time there though...but it has some low key tourist attractions. I know next to nothing about Bennington, only ever passed through on my way to ski resorts. It isn't close enough to them to stay there. But both will likely do better due to being under that enhanced band. Stratton Ski resort which is at 3900 feet in south central Vermont looks to be a likely jack zone. There are some little towns in and around Stratton up in the mountains there also. The good news is I have been in Vermont during some epic snowstorms...2 ft plus...and you can get around. Because the ski resorts are important to their economy they keep the roads pretty good even in the middle of a blizzard. By their standards a 6-12" storm is NOTHING so if you want to get out and about you will be able to get around...just don't rush and be safe!

After that...where we go into Feb really depends on what happens with the TPV. This look is universal across guidance at day 15 The CFS and Euro weeklies both agree on how this evolves...the extension of the vortex near AK lifts, the ridge under it builds up into the EPO domain...and this dumps cold into the CONUS and centers a trough in the Ohio Valley. This is actually a good look...look at the EPO snow mean in the climo thread. However...the long range guidance is suspect and if it is wrong about the vortex lifting near AK...this is an alternative progression if the vortex remains anchored the way it is day 15 and the NAO remains positive (and NOTHING indicates it wont). The analogs to the day 11 look are split between how that evolves with about half going the way the weekly guidance suggests...and half going the "gave over" way above. So...I guess the question is...do ya feel lucky?

The day 10-15 window still looks workable. This is from the 0z EPS but the look across guidance is similar Ideally we would want a little lower heights near the blue x and the ridge centered near the red x...but those are not big shifts for that range...and that is being really picky. This has flaws...this is not a cold pattern, the extension of the vortex into AK is cutting off any transport of true arctic air into the US, and the likely problem here is temps. But mid winter...we can sometime overcome that with a good track and marginal temps. This is about as good a pressure profile as we can get for a day 10-15 period. And the snowfall mean shows where the chance of snow is during this period...again temps are the possible issue It's not a perfect or great look...but its not the worst and we have lucked into snow in this look before. Just need some things to break out way this time.

Wanted to explain what happened to degrade our chances of snow next week. Barring a shift in the north atlantic pattern (and I touched on that yesterday) next week is looking very unlikely to produce snowfall. The guidance miscalculated what happens with the vortex in the north Atlantic the next few days and that sets off a negative chain reaction for our snow chances. From 7 days out the guidance actually nailed the current look pretty much. They might not have had the WAA EXACTLY where it will be...but missing a discreet detail like that by only 100 miles from 7 days away is NOT a significant error and well within acceptable range. Sucks for us but...what happens after this was due to an error in one major feature. Below is what was supposed to happen...That atlantic vortex was supposed to slide across the atlantic, the "storm" this weekend would move into its place...and the flow over the top of that would pump the ridge over Canada and end up centered as shown below. But that isn't what is happening. Instead that Atlantic vortex is going to phase into the TPV over Greenland...strengthening it and anchoring it over Baffin Island...that then also absorbs the storm this weekend up into it...creating a vortex that was not supposed to be there over Baffin...which alters the flow forcing the ridge to shift further southeast...and be centered over the Northeast instead of near Hudson Bay. So we end up with this look....instead of a ridge centered back in Central Canada. That of course shifts the trough well off the east coast. One major miscalculation in a significant feature in the north Atlantic degraded our chances of snow severely. Of course right after I post this the op euro says...wait a minute. There are enough random runs within the ensembles and an occasional op run...that manage to bring down heights to our northeast enough...(as I touched on the other day) that the threat is not completely dead. But it's unlikely IMO... it would need to overcome the ridge being centered too far southeast of where we want it. But guidance could trend back the way we need it...but as of right now the look above is why what was a very good look 5 days ago became mediocre at best.

@C.A.P.E. The solar correlation isn't as simply as some think. On top of what that study showed, which is at times the correlation between solar and NAO have flipped, during the last 50 years there seems to be an opposite effect based on the QBO state. The impact of the QBO on the PV seems to change based on the solar. Unfortunately this year we had what we want during low solar, a descending transitioning QBO and it has yet to do us any good. Isotherm brings up some interesting factors regarding AAM that I honestly have not done much research into and therefore do not factor into any of my calculations. But what I noticed when I did look into his points some... was that the current state of some key circulations are opposite of what we would historically expect given current ENSO and other SST anomalies and indexes. Things are out of phase...and perhaps that does explain some of the odd responses. Like he suggests, some of these other factors being out of phase with what would typically be expected with a descending near neutral QBO in a warm neutral low solar...could be countermanding the typical response to such a state.

I don’t like to disappoint

Every time a threat fails or a pattern degrades some variation of the “I told you so” posts start. Except almost no one thinks snow is likely here. Even when the pattern looks “better” often that just means we have a 25% vs a 5% chance. Most here know our climo. We’re just tracking for fun and knowing every once in a while we get lucky. Telling us told you so is like saying “haha” every time you don’t win the lottery. Oh you told us so? Really. Thanks Nostradamus, really went out on a limb there. Those people look smart 80% of the time until it finally does snow then they look stupid. Of course they disappear when that happens.

I could make a generic forecast like that and it would be right 80% of the time. But thanks for reminding us what normal is around here.

Naw at the end it’s heading the same way the eps and weeklies are. And that’s not bad. But it sucks we might have to wait. Sucks more if it’s wrong and the op gfs is how this goes...