Uncertainty

That’s some ridge that passes through next week, maybe not quite record breaking but notable. Btw if the cold easterly doesn’t materialise this time it’s not a forecasting disaster. It was never really anything other than a gfs pipe dream and has never been supported accords the suites. You would expect ec ops to be showing it by now although hopefully the UKMO has gone to far the other way. The gfs has done well with the pattern change idea and in general. It remains frustrating but not to the point of ignoring it. As I predicted Exeter did put a caveat in but unless the whole lot tilt to stonking easterlies tomorrow morning then it’s back to the original plan. Hopefully with a long detour around dry high pressure before the late Feb fireworks.

Yes if today’s charts are on it the seasonals and indeed the subseasonals from just yesterday are done for. This scandi pattern will be a huge factor in determining the course of the next 12 weeks. You have to say that it’s now the favoured evolution but what form will it take? ECM would be dry possibly chilly but it’s still lots of steps (via 3 or 4 different anti cyclonic wave breaks) to get a snowy easterly vis the gfs. The ensembles favour the former but given the weak strat and mjo analogues you can’t rule it out. Can see a cold caveat appearing in the Exeter outlook this afternoon.

Not gonna post individual perturbations but, as Luke says, have a gander at number 9. That’s the absolute stonker we’ve been waiting 5 years for on here… Again, for newer folk / lurkers: The quick cold evo is highly unlikely. But what a buzz they’ll be in here if it’s still there come Friday morning…

That’s quite a mean Luke. Though we need at least two, possibly three days of upgrades to reel this one in. It could all collapse in one suite though. But the trend tonight has been really really strong in favour of those scandi heights.

What have we said all along Feb, cold March looks as close to nailed on as can be. Really intriguing evening of output. Virtually all output more amplified and support for the elusive scandi has jumped from virtually impossible this morning to border line likely if one were to take the output at face value. Gfs / ecm / gem / icon / navgem all flirt with the idea to varying degrees. Me? I’ve been duped by phantom scandi heights in the 8-10 so many times (7/8 don’t verify imho) that I’ll wait a while longer before believing it. But an eyebrow has most definitely been raised

The mean is also far more amplified, relative to the 0z I think we can say now that a return to unsettled westerlies is still favoured after the day 6-9 ridge (uncharacteristic good work from the gfs there). BUT, there is a small but real chance of a scandi or more likely sceuro ridge holding the Atlantic back in the extended. Zonal Oblivion will have to wait another day.

It’s blue pill or red pill!

Last night we were staring at a period of oblivion - and a very well signposted one at that. As I’ve stated before I’ve had U.K. high —> westerlies —> big block is the progression. But I expected the middle phase to last into the 2nd third of Feb. The ecm last night was just about as bad as it gets. The 12z gfs op last night was completely and utterly on its own. A shining light of hope in an otherwise barren sea of desolate output. And yet, tonight, the gfs op (again), GEM and EC Ops are suggesting an amplified U.K. high - and not one that looks like flattening quickly either. The ensembles aren’t there yet, but have trended in that direction. So why the shift? And will it be gone in the morning? The mjo seems keener to stick in high amp phase 3, I’ve always found p4 promotes flat westerlies in winter. The Paul roundy regressions for Mid Feb are really really interesting, but don’t necessarily explain the present shift. Could it be the strat? Perhaps - a bit early for a QTR. I don’t know. The strat pattern doesn’t scream exactly trop easterlies though. But what I do know is that if the zonal winds were v strong or strengthening, the block would be far less likely. I’m very wary of this change. It is incredibly rare to go from this: To this: But what I do know is: I know which one I’d prefer! Original post: https://community.netweather.tv/topic/98196-model-output-discussion-new-year-and-beyond/?do=findComment&comment=4797702

Ec46 says no. No to any more winter whatsoever. It was wrong about the blocking continuing into January and it better be wrong this time or it’s feb2020 part two.

Last night we were staring at a period of oblivion - and a very well signposted one at that. As I’ve stated before I’ve had U.K. high —> westerlies —> big block is the progression. But I expected the middle phase to last into the 2nd third of Feb. The ecm last night was just about as bad as it gets. The 12z gfs op last night was completely and utterly on its own. A shining light of hope in an otherwise barren sea of desolate output. And yet, tonight, the gfs op (again), GEM and EC Ops are suggesting an amplified U.K. high - and not one that looks like flattening quickly either. The ensembles aren’t there yet, but have trended in that direction. So why the shift? And will it be gone in the morning? The mjo seems keener to stick in high amp phase 3, I’ve always found p4 promotes flat westerlies in winter. The Paul roundy regressions for Mid Feb are really really interesting, but don’t necessarily explain the present shift. Could it be the strat? Perhaps - a bit early for a QTR. I don’t know. The strat pattern doesn’t scream exactly trop easterlies though. But what I do know is that if the zonal winds were v strong or strengthening, the block would be far less likely. I’m very wary of this change. It is incredibly rare to go from this: To this: But what I do know is: I know which one I’d prefer!

It also shows a euro trough at the back end. The strat stays weak throughout too. The mjo returns towards the WP in Feb. Regimes look decent. You can see the middle period where a +NAO could occur, though it’s not a certainty like last winter. In fact, lots to like about it. I’ve been keen on mid/late Feb into March since December. Why? - Mjo moving towards p6/7 - Strat downwelling effects (or, at the least, a lack of interference from a strong strat) - Early signs of sub seasonal modelling sniffing out the idea Still think U.K. high —> westerlies —> -NAO is the mid winter punt. Duration of each phase will be the tough one to pin down. Original post: https://community.netweather.tv/topic/98196-model-output-discussion-new-year-and-beyond/?do=findComment&comment=4794518

I don’t think I really did, though didn’t rule it out with the mjo in p7 for a bit. The 46 wasn’t keen either until pretty late on. If we do get the big finish in Feb that’ll be three notable cold spells with westerlies in between. Not a classic winter but a ‘proper’ winter with wind and rain but some genuine cold to boot. I will miss this Nina when it’s gone. The weather for the past 3 years has been interesting, varied and generally blocked. Can’t see that for 23/24 with a Nino and SMAX. Tbf the GEFS toyed with this cold snap from quite a way out. Still useful as a trend spotter.

It also shows a euro trough at the back end. The strat stays weak throughout too. The mjo returns towards the WP in Feb. Regimes look decent. You can see the middle period where a +NAO could occur, though it’s not a certainty like last winter. In fact, lots to like about it. I’ve been keen on mid/late Feb into March since December. Why? - Mjo moving towards p6/7 - Strat downwelling effects (or, at the least, a lack of interference from a strong strat) - Early signs of sub seasonal modelling sniffing out the idea Still think U.K. high —> westerlies —> -NAO is the mid winter punt. Duration of each phase will be the tough one to pin down.

Also the day 8+ trend today is retrogression of the U.K. / Scandi ridge —> height rises in the Atlantic. Check out the more vertical jet profile of the pub run near Greenland compared to the 12z 18z 12z Clusters at 264 also keen on Atlantic height rises. The SPV leaving that area leaves the door ajar. GEPS on the same page A flattening in the morning takes us back to a U.K. high. A correction north and things get really interesting. Original post: https://community.netweather.tv/topic/98196-model-output-discussion-new-year-and-beyond/?do=findComment&comment=4791641

The scandi-Greenland dipole would be off the scale there. Lots of research correlates that pattern with SSWs. Maybe that’s why we’re seeing the huge 2nd phase of the warming in the strat in the extended. It’s there across the GEFS/ GEPS. Even if we don’t split it first time (day 11/12) we might obliterate it altogether by the early Feb. The mjo in p3 isn’t normally great and perhaps explains the westerlies on the 46, although there could be some flushing down of strat westerlies in the mix. Either way with the strat forecast and if that dipole comes off day 7 in the trop then I wouldn’t bet against an epic spell in Feb. The cold pool that has built over Siberia all winter is the prize. And what a prize it is. February is absolutely up for grabs. Original post: https://community.netweather.tv/topic/98196-model-output-discussion-new-year-and-beyond/?do=findComment&comment=4791624

The main thing vis the strat is that what is not presently forecast is a strong vortex dominating proceedings late Jan early Feb like most winters recently. The strat weakening is already a factor in the blocking we are now seeing in the output because it’s unlikely it would be occurring during a period of VI or under an SPV of doom scenario. Whether we get a displacement or split is important but the location of the remnants will also be critical. Either way, I’m just glad it’s forecast to weaken. It is notable just how incredibly hot the gfs op runs are getting for this second burst As a strat fan, I would love to see what happens to the vortex next. My guess is a total collapse, but it’s still out of the reliable. The Paul Roundy charts for our forecast mjo progression however are ugly, at least those for p3 and 4. Thus I’m rarely confident in high lat blocking benefiting us under that regime hence I do think the N U.K. high might well be what we end up with day 7-15. Beyond that it’ll be a) downwelling effects, if any and b) how quickly the mjo gets out of the IO and on its merry way back to the pacific. Right now it’s virtually impossible to reconcile them but I’m sticking to my late Feb / early March big time blocking forecast I made previously. U.K. high and then a more westerly spell in between. There are some eps/GEFS members that get more out of the extended period but not convincingly so. The back end of both models are westerly. With the strat shenanigans however, nothing is off the table. Original post: https://community.netweather.tv/topic/98196-model-output-discussion-new-year-and-beyond/?do=findComment&comment=4792045

The main thing vis the strat is that what is not presently forecast is a strong vortex dominating proceedings late Jan early Feb like most winters recently. The strat weakening is already a factor in the blocking we are now seeing in the output because it’s unlikely it would be occurring during a period of VI or under an SPV of doom scenario. Whether we get a displacement or split is important but the location of the remnants will also be critical. Either way, I’m just glad it’s forecast to weaken. It is notable just how incredibly hot the gfs op runs are getting for this second burst As a strat fan, I would love to see what happens to the vortex next. My guess is a total collapse, but it’s still out of the reliable. The Paul Roundy charts for our forecast mjo progression however are ugly, at least those for p3 and 4. Thus I’m rarely confident in high lat blocking benefiting us under that regime hence I do think the N U.K. high might well be what we end up with day 7-15. Beyond that it’ll be a) downwelling effects, if any and b) how quickly the mjo gets out of the IO and on its merry way back to the pacific. Right now it’s virtually impossible to reconcile them but I’m sticking to my late Feb / early March big time blocking forecast I made previously. U.K. high and then a more westerly spell in between. There are some eps/GEFS members that get more out of the extended period but not convincingly so. The back end of both models are westerly. With the strat shenanigans however, nothing is off the table.

Also the day 8+ trend today is retrogression of the U.K. / Scandi ridge —> height rises in the Atlantic. Check out the more vertical jet profile of the pub run near Greenland compared to the 12z 18z 12z Clusters at 264 also keen on Atlantic height rises. The SPV leaving that area leaves the door ajar. GEPS on the same page A flattening in the morning takes us back to a U.K. high. A correction north and things get really interesting.

The scandi-Greenland dipole would be off the scale there. Lots of research correlates that pattern with SSWs. Maybe that’s why we’re seeing the huge 2nd phase of the warming in the strat in the extended. It’s there across the GEFS/ GEPS. Even if we don’t split it first time (day 11/12) we might obliterate it altogether by the early Feb. The mjo in p3 isn’t normally great and perhaps explains the westerlies on the 46, although there could be some flushing down of strat westerlies in the mix. Either way with the strat forecast and if that dipole comes off day 7 in the trop then I wouldn’t bet against an epic spell in Feb. The cold pool that has built over Siberia all winter is the prize. And what a prize it is. February is absolutely up for grabs.

Yep. They’re a useful tool for picking out trends in the extended. The op has obviously been garbage since the upgrade… it’s gone for every variety of scandi heights in the extended for over a week now - maybe one of these days it’ll have it right. Tonight perhaps? I’d forgive it somewhat if we got that. A 2012/13 variant with a major warming to follow. You’re learning quickly pal and doing some good analysis. The noaa charts and the analysis that go with it are still ‘as good as it gets’ in terms of analysis most of the time. You’ll also figure out that they are often as uncertain as we are, even for the 6-10…

Until now that is! Agree we need to give it a few more suites.

Looks more like after an ssw than before! Is the mean that enthusiastic? There was a set a few days ago that had no -NAO but the mean was uninspiring. @Catacolthe gfs op was updated but the GEFS weren’t. Random member x probably verifies better than the op!

Equally unlikely, but even more alluring… jma tonight… I guess with the gem, ec, jma ops looking interesting it’s not necessarily zonal oblivion for mid Jan. The jma finishes the strat off mind. Huge Aleutian low anomaly with an even stronger scandi - Greenland dipole. So many options in the extended .

Slight mismatch over the Arctic

Absolutely, categorically…Won’t happen. Why? Doesn’t look or evolve like other output. It’s the ec op. It’s 240 hours away. But I’m posting it because… It’s nice to look at