Uncertainty

It is the best of a bad bunch at that range. It is the hardest forecasting domain, seasonal is easier in a way for broader patterns. 10-30 days is v difficult when background signals say one thing but modelling says another. That’s why I like it I guess. But essentially you’re right. I was trying to say I trust the humans more than the modelling at that range, but I’d prefer both on board!

Yes I’ve been tracking this one too. UKV has been consistent in forecasting a broken band of potentially severe t/s tracking north along the cold front. Not good for the cricket potentially! Beyond that and after the trough does finally push through (looks like Tuesday?) the ecm has a go at building heights from the SW but it looks like hard work. I still agree with Tamara / Matt / Dan etc who have been consistent in the pattern shift later in the month but the ec46 is getting really twitchy about it and has no discernible hp anomaly anywhere near the U.K. throughout.

Although the general pattern for next weekend looks nailed on, with a low stalling west of the U.K. drawing up a weakish ridge to the east amid a still generally -nao backdrop… the detail e.g. how far west the low sets up, will define the weather we get - and the outcomes range from a low plonked over us (ecm 12z) to being so far west it ends up baking hot and dry (last night and today’s gem). Lots of in between options with moist s/westerlies too (UKMO/icon) You do get the feeling that the ecm and gem are starting to explore the hot and dry option, or perhaps the 4th and most explosive solution?? The 268 chart on the ecm would have set the pulses racing I think… Mid July has a strong singularity (esp recent years) with hot shots so it’s not to be discounted. After this the models tend to sweep a mean trough through and the new daily 100 strong member ec46 is getting a bit twitchy with the late July U.K. high…. but that’s for another day.

One blue border cluster does not do the back end of the eps justice! Looking through the members, there are wedges everywhere, lots of Atlantic energy yes, but i think the idea of a flat westerly with no blocking after day 10 is a bit far fetched. Especially considering the high sigma mjo p7/8 amplitude ahead and of course the multiple downwelling waves from the strat. The GEM ensembles have been starting to hint at a wedge appearing over scandi towards the end. I think this could be where we’re headed. The big question in the meantime is where the Atlantic energy goes day 9+. The ec op looked like the mildest option but there are some very plausible options that take a low through the channel area which would of course bring a significant disruptive snow event should it manifest. Last thing from me, it really does look like an El Niño is coming, the huge westerly wind burst associated with this mjo wave surely paves the way for the end of this 3-year Nina event. The spring forecast barrier is often real but modern times haven’t seen a 4 year Nina and there’s no evidence this will be it.

Stunning straight line northerly with a feature running south on the gfs Gem looks like it would end up similar. This fits neatly with MO wording and the themes the 6z ens were exploring.

That ladies and gentleman: is a mean. Save for it getting sucked too far westward, disruptive snow and cold are coming, right on cue, from the first weekend in March. All 3 ensemble sets have a mean GH, a strong one at that. It could go wrong of course; but it’s the strongest signal I’ve seen for an impactful GH signal for us since 2010.

Significant northward shift on the GEM for the initial easterly. 0z 12z Ends really interestingly as well. Notable as the gem hasn’t been keen on any kind of genuine cold pattern until now. UKMO further north too… Plenty to play out as the models resolve the downwelling and the second warming, as well as the strength of the mjo and solar factors they understand little. It may be too little too late for major snow from the initial easterly but the early March cold blast from the north is absolutely in play.

Bev I would say model agreement is actually already higher than average due to the ssw, take a look at the mean anomalies of the big 3 ensemble sets at 360(!) hours out… EPS GEPS GEFS I would hazard that the ssw is responsible for this agreement. The MO often state that a super strong OR super weak PV increases the general accuracy of trop forecasts. The above is testament to that. Hope that helps and agree your question and others of new/learning/any members should be addressed to foster cohesion and togetherness on this thread. Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4808523

Bev I would say model agreement is actually already higher than average due to the ssw, take a look at the mean anomalies of the big 3 ensemble sets at 360(!) hours out… EPS GEPS GEFS I would hazard that the ssw is responsible for this agreement. The MO often state that a super strong OR super weak PV increases the general accuracy of trop forecasts. The above is testament to that. Hope that helps and agree your question and others of new/learning/any members should be addressed to foster cohesion and togetherness on this thread.

I’m surprised by the lack of enthusiasm for this spell on this thread. We spend years looking for charts like this and now they’re coming there’s barely any interest. I looked back through the 2018 threads and the difference is remarkable: joy, anticipation, camaraderie, detailed analysis. This time I’m sorry to say it’s been cynicism, doubt and a general feeling of ‘whatever’. This is not a diss at any one person, on the contrary, it is a call to arms: Let’s inject some passion and excitement (not to be confused with hyperbole or inaccuracy mind) into this thread. We may be looking at an exceptional late Feb/early March spell (as many of us have been suggesting for months) and our commentary will be vital for many learners and observers looking for the truth amongst the ridiculous headlines and naysayers. As I have stressed before, the internet is quick to judge this thread and it’s reputation has taken a hiding in recent years. We spend enough time on here… let’s make it worthwhile First up: The icon has snow showers peppering the east coast early next week. It has sharpened the initial amplification as the day has gone on, the jet angle is now near vertical. This is a key component to a snowy easterly, and we should look closely at the gem and gfs to see if they can replicate or outdo it. The latter was a bit nondescript earlier. I have a feeling it’ll flip to an icon-esque outcome. We’ll know soon. Thanks all Josh Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4808509

I’m surprised by the lack of enthusiasm for this spell on this thread. We spend years looking for charts like this and now they’re coming there’s barely any interest. I looked back through the 2018 threads and the difference is remarkable: joy, anticipation, camaraderie, detailed analysis. This time I’m sorry to say it’s been cynicism, doubt and a general feeling of ‘whatever’. This is not a diss at any one person, on the contrary, it is a call to arms: Let’s inject some passion and excitement (not to be confused with hyperbole or inaccuracy mind) into this thread. We may be looking at an exceptional late Feb/early March spell (as many of us have been suggesting for months) and our commentary will be vital for many learners and observers looking for the truth amongst the ridiculous headlines and naysayers. As I have stressed before, the internet is quick to judge this thread and it’s reputation has taken a hiding in recent years. We spend enough time on here… let’s make it worthwhile First up: The icon has snow showers peppering the east coast early next week. It has sharpened the initial amplification as the day has gone on, the jet angle is now near vertical. This is a key component to a snowy easterly, and we should look closely at the gem and gfs to see if they can replicate or outdo it. The latter was a bit nondescript earlier. I have a feeling it’ll flip to an icon-esque outcome. We’ll know soon. Thanks all Josh

The GEM ensembles are a stonker. Haven’t said this since Feb 21… I’m getting BFTE vibes…

A ‘mini beast’ on the ecm this morning. The orientation does manage to squeeze a cold pool through but not convinced the precip would be notable. The gfs has been setting the tone here and the others are responding. Will it be right about the huge retrogression sequence? I think it will be. The combination of downwelling and mjo lag is a rare one indeed. 2018 was ‘too much, too fast’. Oftentimes the so-called west based -nao is weak as well as west - making influence over NW Europe difficult. This time the high looks ominously large, potentially influencing both sides of the Atlantic. If the gfs stays consistent on this and the mean charts show a cut-off GH (they don’t yet) then we can call it. For now, it remains a tantalising possibility. Albeit one supported by teleconnections rather than hindered by them.

I get your point Mucka lad but I’m not sure ‘flat’ is the adjective to describe the gem! For sure it’s not outlandish like the gfs but it’s still pretty amplified and wouldn’t take much adjustment to get a lot colder. The UKMO is quite unremarkable though. Yet another U.K. high for the upteenth time this La Niña. I’ll miss them when they’re gone mind, just not after a double dip ssw / mjo p7 combo! The gfs looks great but after all the bother we’ve had with it since the upgrade it’s irrelevant until supported by at least one of the other 3. It is a plausible evolution though so the ecm, as ever, will be worth watching tonight.

Y’know Si I saw that mean and it reminded me of 2018, when we saw that mean easterly on the eps/GEFS and, despite some notable op wobbles, it counted down beautifully. From a metrological perspective, I would love to see that evolution again. This time with a more stable retrogression to Greenland. It’s going to be an exciting week or two in here I think…

The trop vortex over Greenland still looks strong at day 11. I think we’re looking at scandi heights developing late Feb. Obviously the million dollar question would be can we get the strength and orientation right. You can’t rule a BFTE out, that’s for sure, but it still isn’t the form horse. It would only take one more big push from the above northward and things would get very busy in here indeed!

We are (understandably) debating the ‘why’ driving the outlook, me included, so I’m going to focus on the modelling for a while… but the last thing I will add wrt the strat is that the euro blocking regime (which we presently have) is the ideal regime for assisting the downwelling and resulting in a GH further down the line - have a look at Domeisen et al (2020) for more details. @Dennishas kindly posted it on Twitter. Notably, at day 10, the big 3 have significant ridging to the W/NW @Lukesluckybunch it gets awful close mate! We’re trending towards something quite significant end of week 2, there’s lots of time for upgrades. It feels like it’s all ‘coming together’…

The op is frequently wrong at 120-144 let alone the end of the run. I don’t care what it says anymore, until they update it again it’s completely useless. The GEFS look very settled at the end. Ec op is known for its amplification bias but it’s really keen on heights where they’ve been so much for the past 2 years or so - just to the NW of us.

I think you’re gonna be right Pete. We’ve said it all along. March is going to be mental. I still think the big action is over 15 days away, and the murmurings in the eps will continue to be just that for a time. But from the last week in Feb onwards, it’s going to be Very, very interesting. Tropical, solar, strat and now extended modelling support for a long await blocking spell.

We’re still a good week or so for anything of interest trop chart wise. The reversal is still nearly a week away and the mjo whilst propagating is still in the +NAO phases. However, the 0z eps chucked a curveball with an ahead of schedule FI dominated by MAR and -NAO types The latest GEPS is also sort of flirting with the idea This is quite a new signal, the extended range has been dominated by +NAO for a while now. The GEFS are less keen but the odd member really goes for an Atlantic ridge. It’ll be v interesting to see where the ec46 takes the 0z eps signal. Any high lat blocking was previously progged for early March so we will need to examine the week 3 and 4 signal closely to see if there’s been a change. For the end w2 changes, Less time in phase 4 seems the more likely reason rather than a QTR but certainly the weakening zonal winds do allow for such mjo effects to take hold… Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4804055

FWIW, I think the 46 will go more blocked in weeks 3 and 4. The cfs and JMA weeklies are heading that way. Weeks 3 and 4 JMA weeklies

We’re still a good week or so for anything of interest trop chart wise. The reversal is still nearly a week away and the mjo whilst propagating is still in the +NAO phases. However, the 0z eps chucked a curveball with an ahead of schedule FI dominated by MAR and -NAO types The latest GEPS is also sort of flirting with the idea This is quite a new signal, the extended range has been dominated by +NAO for a while now. The GEFS are less keen but the odd member really goes for an Atlantic ridge. It’ll be v interesting to see where the ec46 takes the 0z eps signal. Any high lat blocking was previously progged for early March so we will need to examine the week 3 and 4 signal closely to see if there’s been a change. For the end w2 changes, Less time in phase 4 seems the more likely reason rather than a QTR but certainly the weakening zonal winds do allow for such mjo effects to take hold…

That’s last months Si. wait till you see the updated version!

The U.K. high —> westerlies —> big time blocking take for Feb into March I and others have been plugging is still on track. The first brick in the wall is nailed on. The gfs has been more right than the euros on this, but obviously the op took it too far (the dodgy new upgrade clearly over-amplifies). The westerly phase also looks well supported. The big three in mid Feb look ++nao The mjo passing through p4 is, for me, our most ‘westerly’ phase, even in a Nina. By the end of Feb though, as the now highly supported strat warming effects kick in and the mjo departs P4, we are looking at a blocked, possibly severe March. The 15-18th Feb looks like the landing point for this next warming and it looks more likely to make it as a major ssw than the milder version we had recently. CFS is really keen on a 2018 style high amp P6/7 push. Eps less so but same direction. The early projections from the 46 for March are only illustrative, but a spell of blocking is the logical outcome to the strat/mjo progression. Whether we ‘like it’ or not, This is the way the cards look to have been dealt. Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4801210

The U.K. high —> westerlies —> big time blocking take for Feb into March I and others have been plugging is still on track. The first brick in the wall is nailed on. The gfs has been more right than the euros on this, but obviously the op took it too far (the dodgy new upgrade clearly over-amplifies). The westerly phase also looks well supported. The big three in mid Feb look ++nao The mjo passing through p4 is, for me, our most ‘westerly’ phase, even in a Nina. By the end of Feb though, as the now highly supported strat warming effects kick in and the mjo departs P4, we are looking at a blocked, possibly severe March. The 15-18th Feb looks like the landing point for this next warming and it looks more likely to make it as a major ssw than the milder version we had recently. CFS is really keen on a 2018 style high amp P6/7 push. Eps less so but same direction. The early projections from the 46 for March are only illustrative, but a spell of blocking is the logical outcome to the strat/mjo progression. Whether we ‘like it’ or not, This is the way the cards look to have been dealt.