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Everything posted by psuhoffman
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One thing I forgot to point out, don’t let temp anomalies fool you. As long as we get a temp profile back close to normal the storm track is more important. And that works both ways. We can have a high of 45-50 but if the airmass is reasonably dry and a system tracks under is it will snow. On the flip side we can see a 5 day mean (or a day 10 mean) showing cold because behind a wave it gets cold and the boundary pushes to our south but it systems are too amplified and the ridge axis it too far west on the pac side when the next wave comes it will cut west. So the pattern looks cold but it’s warm when it’s precipitating. We all know that cycle! We need to wait for the details we can’t know yet to find out whether this is actually a good look or not.
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Fine….. This is the first serious pattern analysis I’ve done in a while, hopefully it’s warranted and there are more of these coming. First of all I don’t see a can kick YET. EPS at day 10 looks almost identical to previous runs. Whatever differences are incredibly minor for day 10 and noise imo. The eps was always taking longer to initiate a colder thermal regime after the longwave pattern shift but that’s simply because it doesn’t have the same cold bias as the GEFS and so it doesn’t just magically snap cold instantly the way the Gfs likes to do! The actual pattern change remains the same on the eps. Doesn’t mean it’s correct or real, we aren’t in the safe zone yet but no signs it’s a head fake as of now so I guess it’s time to take it more seriously and start a deeper look into what it could mean. This is the 5 day mean day 10-15 for reference sake I’m posting the best example of a similar pattern that worked out in a big way here Jan 2014 This is not a prediction I just want something to reference for comparison and as a what to look for. The most prominent features are a full latitude easterly centered epo ridge with a ridge bridge over the top with a -AO and a WAR. The similarities to 2014 are evident but that doesn’t mean similar results. But this pattern is fairly rare. It’s not that 2014 was a rare outcome it’s more that 2014 was a rare pattern combo to lock in for a long period. There aren’t that many good comps one way or the other. But from the few there are there are several keys to success 1) location and orientation of the epo ridge. It cannot end up any further west than it is right there. That’s already living dangerously as it is without more PNA help. So far the gefs and eps have been slowly heading towards a compromise. That’s ok so far so long as that compromise doesn’t end up any further west with the pac ridge that currently projected. 2) the orientation and depth of the CONUS trough. We don’t want it too sharp or deep. That would lead to a cutter quick cold shot and moderation pattern cold dry warm wet. We want a more SW to NE oriented trough which is what the eps shows above at the moment. We need to watch for changes there. 3) The amplitude of the WAR. In this look some war can actually help keep waves from being squashed IF it’s suppressed some. We don’t want to see the WAR building up into the 50/50 space. All 3 of these factors play off each other. If the pac ridge shifts east then we could survive a little more WAR and or trough amplitude. If the pac ridge shifted east into a pna ridge then we would actually want a deeper trough. If the epo ridge shifts west at all we would need more NAO help and a 50/50 (way less WAR) or we would be toast! It’s a interrelated equation and each factor influences the others. Lastly what made 2014 work in this look was that there was a constant wave train along the boundary but almost none amplified. There was just a constant train of weak progressive waves. It’s amazing some of them ended up dropping 8-12” in places frankly given the lack of amplitude but that might be a new normal where it takes less to create a respectable qpf event. But anything amplified would likely cut. There were only 3 truly amplified waves that winter and 2 did cut. The other in Feb tried but it initiated really far SE and there was such a cold airmass with snow cover everywhere over the top of it. It did still flip to rain in the cities though. But trust me given our total lack of arctic air lately we don’t want to try that game again. We need the waves to eject in a progressive way and not an amped up cut off system in that pattern. We won’t know those details until we’re much closer, for now we wait and hope.
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The EPS isn't a can kick...it was NEVER showing colder anomalies making it into our area until after Jan 25 at the earliest. If you compare the h5 from previous runs and last night, and I am about to in a post I am working on now, the pattern at day 10 from last night is nearly identical to previous runs. The GEFS was bringing in cold a lot sooner, when isn't it, and it is starting to can kick because it is coming around to the EPS/GEPS. In reality the two are meeting in the middle, the EPS has backed off the PNA a bit in the long range and focused more on the EPO but not as bad as the GFS. A compromise here can work. I haven't seen indications of a can kick YET...but we arent within safe zone yet and even if we get this pattern change there are imperfections and issues that could still mean no snow for you if the details within the pattern don't break out way but I will get into that in my next post.
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Not overly. I’m more concerned it’s just wrong about the pattern. There is a wave around the 20th that’s going to go north of us. But it’s also very likely the next wave around the 23-25 does also. Imo it’s likely to take multiple waves to establish a cold enough regime. That puts our first good opportunity near the very end of the eps run. And by then the war is getting beat down and it looks like a more favorable setup Imo. The mean does start to increase some at the very end. I bet if it went out another 72 hours you would see something. But ya it is concerning that the pattern on the eps only seems to cool temps to near avg. It should be way colder. But we aren’t having that talk again. Personally if we get the eps pattern and it’s too warm I’d rather find that out and know. Then at least we can end the debate!
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Imo they are all just tools. None of them are useless but just like you can’t use a hammer alone to build a house no one of these products alone is sufficient to make a forecast. In this case the mean is skewed by outliers. But a quick look at the probabilities output identifies that. No harm to foul. Trying to use one product to base a forecast is user error. But if you look at all the evidence, including historical reference, it can be useful. We’ve known at least 10 days in advance of each pattern change this year going back to October. We even knew by 5 days out that the snow threat was zilch in most cases. I think guidance has been pretty good, it’s just not been what we wanted!
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Is it a can kick or is it just showing the details more clearly as it gets closer and there is less washing out due to variance and timing differences. This was always how I figured it would actually look given the gefs longwave pattern. Other than one run where it temporarily caved to the eps I never really liked what it was offering.
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It's done...good luck to us all
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Oh I am SURE we are still capable of a good pattern and snow. I've said numerous times that a lot of these patterns we've been in recently would have been pretty sucky in any time period. We've been in a bad cycle in terms of the most important factor, the pacific. But at the same time...I think its true that kinda sucky is getting worse. My point was if we look at past comp periods we were able to often salvage SOME SNOW out of those periods with a perfect track system in an otherwise crap pattern, where as now...its weeks and weeks of no hope because a positive anomaly pattern is now so freaking warm its just shit the blinds time.
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I've NEVER started a long range thread. Should we give it a shot?
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Strong el nino El nino's are generally a good thing but if the pacific trough is too strong and too far east it can be "too much of a good thing" and flood the CONUS with MP air. 1992, 1995, 1998 being other examples where it didn't go the way we wanted.
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GEFSX looks GREAT for my PD Colorado trip.
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The GEFS has a similar evolution to a canonical Feb nina look though. That doesn't mean they are right but both had the colder look recently and both evolve the same way. Another reason I keep saying root for the EPS. It may be the least cold but its a more sustainable pattern than the GEFS look.
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So does the GEFS ext. By Feb 1 we are back to a no hope hostile torch pattern that looks to last a LONG time. And best part...it does it in the complete opposite way. We go from an unworkable Pac trough nino pattern to an unworkable Pac ridge Nina pattern. Unfortunately this was my fear that I said a couple weeks ago. How long do we really expect the pac jet to relax for? How long has it relaxed recently? Problem is if the pac jet resumes it stronger base state we are left with such a narrow path to victory. Pac trough and the jet cuts under and floods MP air in, ridge and it goes over the top and still floods plus it puts whatever trough there is in the west. Either we we lose. We basically need an absolutely perfectly placed trough right near the Aleutians but not too far east or west to have any shot in the current base state. There are way way way more losing configurations than winning ones when the pac jet is enhanced like this.
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