SW Saltire
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Posts posted by SW Saltire
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A couple of charts from tonight's JMA and BOM to calm the nerves a little.
JMA 192..
J192-21.gif BOM 240..bom-0-240.pnggreat avatar ABNS.
The BOM is fed with similar data to the UKMO is it not? with lower resolution... so therefore that is what the UKMO would go onto show -flawless logic
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C'mon folks no point chasing illusory cold the games up for the foreseeable
I'm a mega coldie but I'm not blind.
If this was the ECM ens then maybe it would have some credence. For a 'mega coldie' you seen very adverse to seeing any potential in the outlook. Taking all charts at face value is one think but for a few consecutive afternoons after the 'small' model has given it's daily dose of despair you proclaim that it'll all be over if the ECM operational doesn't show an easterly which is completely untrue. Fortunately, upto now the ECM 12z has been very positive for coldies. If the ens remain supportive of a continental feed overall then how can the Scandi high be dead in the water?
Making such bold claims can only eventually backfire although that's not to say you won't get away with it this time...
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See this link for the maximum gusts recorded during Hurricane Bawbag - http://www.metoffice.gov.uk/climate/uk/interesting/2011_decwind
I remember on the day thinking that the gusts weren't as severe as I had expected, seemed to really get going in the morning and then die down by the afternoon (when it was meant to be at its strongest!). The central pressure doesn't determine the wind speed (although it does give a good indication), it's really how close together the isobars are around the storm. With this area of low pressure on Thursday, the isobars are really packed together due to the steep gradient between it and the strong area of high pressure centred just west of Ireland.
So to sum this up:
Hurricane Bawbag = Lower central pressure, but not as much of a difference between the areas of low and high pressure.
Storm on Thursday = Higher central pressure, but a large difference (gradient) in pressure.
Personally, I'm thinking the wind gusts on Thursday could be as severe / more severe due to this, but not as severe as the January 3rd 2013 storm.
So pretty tame then
Thank you for your reasoning and it's exactly what i thought and yes i believe we will at least see widely 70-75 mph gusts with 90 in exposed places and the worst affected will be over 100 mph. The worry is that even 24 hours ago it was not forecast to be this strong so it seems to deepening more rapidly than expected.
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What kind of gusts did we see with 'hurricane bawbag'? as we might not be that far away, at the present rate of upgrades every single model run. Down to at least 972 mb but with current trends the actual storm could be at least sub 970.
EDIT: after seeing Lorenzo's post it wouod appear we will not reach 957mb but it won't be too far away and it isn't all about the central pressure which determines the wind speed... is it?
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GEFS 12z are mild and are pretty unambiguous in their appraisal of HP anchored to our SE with presumabley the jet way to our north.
They tend to have characteristics of what Blair's 'poodle' MPs. i.e nodding dogs with the operational and tend to flip drastically and uniformly. Hence, i was suprised to see as many as 11 members this morning supporting some kind of easterly
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These winds could cause slight problems if they were the 'gust' speeds never mind the mean! I'm confident at least 100mph will be recorded somewhere and i'd hate to be on cairngorm summit, a bit breezy might sum it up
EDIT : snap Matty M!
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The GFS 12z shows the powerful low, bringing strong winds on Thursday to many northern areas, with a central pressure of mid 970s mb
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Just read back through this tread to March 23rd and i'm sorry i could not have answered the calls that asked if anyone in southern Scotland could update given the snow. As this thread's members seem to be in the central belt or above. It was a very memorable spell looking back, beaten in this area only by years near my birth as i know it snowed in 1995 and i think a year early 90s we had 3 or 4 foot of snow but it vanished after a few days unlike in March last year. The longevity of that spell will take some beating despite the fact is was well into spring (for this my home area at least).
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Battleground set ups were also mentioned with Atlantic incursions happening. Usually get our best snow here from this type of set up.
yes, from an IMBYism pov battleground scenarios are the real deal. Even after the equinox in late march we achieved 6 foot drifts and almost a foot of level snow in Dumfriesshire with more further west, as was seen in Arran. Thus, an easterly, as Ravelin says would need to be very potent although it is usually very clear in the west provoking a continental i.e. sharp frosts, sunny days and if we get a dusting then the low dewpoints will mean it will stay
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Re - trailing segments of vortex, I know that these are complicated charts representing vorticity across an atmospheric layer, however without losing your mind to the physics involved provide an illustration of how the vortex is stretched.
Great post Lorenzo, so the above chart would , in laymens terms, allow a Scandi high to form more easily (if it verifies) as there is little residual vorticity that has been left behind? Was it not mentioned a few days ago that the deep FI Greenland height rises did not come to fruition due to the models underestimating the amount of vorticity left behind.... if so, the above chart show be seen as encouraging but should not be taken as gospel
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The operationals this morning have not shown agreement regarding a future easterly (shock horror). This was to be expected and is simply part and parcel of the run variability that will definitely take place. The update by Ian F is very encouraging but obviously a long way from coming to fruition. It is also good that 11 GFS ensemble members develop some kind of easterly flow as add 2/3rds more amplification and.... if only it were that simple. This is of course the easy part, watching the Scandi high tentatively be brought into nearer FI. Once it reaches high res the real drama will start. If i was living on the east coast it would certainly seem like winter was upon me with temperatures seeming suppressed with the propensity for them to continue to lower, although the magical white stuff looks like a while off for the time being
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HC - Just take it. After 2 yrs of sitting in a box, can you not come up with a justification for using it that somehow also ties in with work (even if it's just a slim link with work)?
Could almost use the overused word 'mild' this morning as it was 9-10C on my drive into work. Dry with mainly grey cloud and just the odd patch of blue sky showing in the distance. Light winds.
Not ventured into the model thread so far today, has their easterly disappeared yet?
See the post from Ian F, which states that the MetO see a very cold pattern developing in the 10-15 day range. This easterly has a long way to go...
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Just a quick question. Does the UKMO have any plans to extend their outlook(to Jo Public) to say 192hrs?With all the technology they have it would be great if they would extend their model accordingly. Even then, it would be less than what ECM and GFS do now but it would be nice to compare the 3 main models at a slightly longer range. Apologies if wrong thread and please put in appropriate one if this is not the one!!
I think if it did our opinion of it would be changed significantly. I mean even the GFS would not be so persistent with it's opposition to blocking as it would have 240 less hours to be wrong!
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As is frequently said, look at the BIGGER picture. Yes, other locations in the globe will be experiencing colder weather but the ECM's later stages are only going to lead to an easterly. I can put up with Greece getting some snow as long as we are also in the firing line!
Regarding an earlier post, i agree Mucka. The GFS never modeled the upstream pattern correctly at all. It has been lauded as winner by some purely through default, i.e. not showing the northerly but it was so reluctant to accept changes.
Thank you for the verification stats, It backs up our suspicions as the GFS is in 4th position, with the ECM easily first. I was actually a bit harsh on the GEM yesterday as the stats suggest that it is only slightly behind the UKMO.
Why is it always the same though? "if the easterly isn't shown on the ECM it's game over" then the GEM shows promise and so does the ECM and it's all aboard the easterly express! If the ECM hadn't shown an easterly it would not have changed that much. This potential easterly will take time to evolve and obviously it could go up in smoke but there will be many trials and tribulations before anything is resolved, we can bet on that!
I'd personally back the GFS in FI over whatever the ECM shows, recent events have shown that people can no longer cast off the GFS so easily for it's 'eastward bias", the ECM is the joke now if anything.
Look at the FACTS! they CLEARLY show otherwise!
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I'll take that. It's currently doing quite well in the verification stats race too.
Does anyone have the verification stats at hand? when are they updated?
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but if you look at the strat charts on the latest gfs notice the vortex over in the Canadian sector.
and not much residual energy over this side.
so there is a gap to send heights in scandi area althouth we need lows to continue into Europe.
the gem is a run from hell the gfs so far is also but im not confident any of the models have the output correct beyond t144.
intresting stuff though and any blow torch I suspect will only be a 7 day event as energy is thrown out of the northern states I think personally that its 50/50 either milder or gradual return to colder.
so its palm trees and bbq with the gfs not seen warmth in December like this for a few years.
I'd agree with most of your sentiments although, unfortunately we don't know how much residual energy will be left over Scandanavia so we will have to wait and see.
Exactly, all output beyond 144 should be treated with caution.
Unfortunately, for the Ski resorts it looks like this milder phase ,that seems inevitable in order to achieve a Scandi high, will wipeout any early snowfall
If we can't have cold then bring on exceptional mild i say! at least it will beat anticyclonic mediocraty
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I wonder will ecm12z stick with the Easterly or is it a dead duck in water?
How does one GFS run that is not even finished yet, constitute as no Scandi high, no potential cold december is over. I don't get it. This is not just directed at your post snowice btw.
Barry95 post proves my point entirely
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Agreed. There is still a lot to cement. I mean, it's not beyond the realms of possibility that it could upgrade every run from now and be an actual stonker of a Northerly, for many many days. Blanketing the country in snow. Alas, people seem to prefer talking about easterlies that aren't even being shown in the deepest realms of FI.
It is beyond the realms of possibility really... you are talking about an incredibly rare chance
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A Greenland block brings a lot more scope for country wide cold and snow than most Scandi highs. You can play around with the orientation, shape and placement of one more than a Scandi high and still pull in some very cold uppers (you can have one fail as well of course) as well HP generally being further away from the UK (Often with a Scandi high high pressure will be across the N of the UK) which helps with potential ppn.
An Easterly can be better for the SE contingent but not necessarily and if there is any IMY'sm it is from the SE contingent generally with a Scandi high because a Easterly will rarely deliver further N and W unless you get the classic battleground set up. I am IMBY with an Atlantic ridge Northerly because I can get Cheshire gap showers but they are rarely any use for the South.
A Greenland block however will generally bring in a NE flow which can be just as good for the SE if not better as the NW depending on the exact set up so I think Nick was spot on with his post. We should always favour a Greenland high over a Scandi high IMO though accepted there is more potential from a Scandi in the SE than the North and West and the reason I chase them is because as well as bringing cold there is potential for retrogression - to Greenland!
Firstly, i wasn't disagreeing with what Nick had said. I was merely posting my reasoning behind why i personally am not that obsessed by an easterly from an IMBY pov (this may change if we get an easterly in february when i am located in Stirling, which is much closer to the east coast than Dumfries). It is simple really, i see far more snow from a greenland block and the battleground scenario can deliver in a very big way for a region affected by the solway firth. Therefore, if i lived in the south of England generally an easterly would give me more snow and therefore i would chase it to verification.
I take your point that a North-easterly can be obtained from a Greenland block as well. I also wholeheartedly agree that a Greenland block is the best and in general most substantial, in this regard you are preaching to the converted
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From what I can understand of today's models is that for us in Scotland it's still on for a cold blast. What I'd worry about is if the cold uppers are in place early enough for us to get snow. For me yr .no has us getting over 13mm of rain on Thu with a temp of 6 degrees before it turns colder, but drier. Then again it's early to predict exact rain/snow fall patterns and being in NE I'm probably better positioned than most since we can do ok from a northerly and will probably hold the cold uppers longest.
Not a bad day here today. Felt colder than the 8C the car thermometer said, especially when the sun went down. Clear skies and no wind means I expect to be scraping the car tomorrow morning.
Sorry, i've only just seen your post. The cold uppers were never forecast to anywhere near undercut the front on thursday sufficiently to turn rain to snow away from high ground. The main event was the copious snow showers brought in on a raging northerly wing which was to last for sebveral days with uppers as low as -14. However, since that earlier prediction it looks like a 36 hour event maybe 48, with far less showers (they'll still be of snow) and not as impressively cold uppers either unfortunately
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Thank you for the reply. The ensemble support of 50/50 is what we see, if the Met-Office were only seeing the same then I think at the very least there would be words along the lines " later on in the period there are no clear indications " blah blah. They have done that in the past, todays update is short and sweet with no wriggle room with no indication what so ever that the Met-office are considering the Scandi High option.
your welcome, I take your point that Mogreps may not have such a strong signal and thus maybe they do not mention it. However, the MetO word forecasts do change at the drop of a hat and if the Scandi high does make it from distant FI to a closer timeframe on different models then i'm sure they'll mention it. As Ian F has mentioned previously, their attention will be on the more immediate future with weather forums such as ourselves already on to the next cold horizon
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Well I've just looked and I don't see an easterly, not even in FI. Maybe, just maybe, the slightest hints of it heading possibly that way maybe, in the very last frame of FI...Hardly even worth talking about. I just always see the same. People obsessed with easterlies / FI and not about the next "real" event.
I think the northerly has been well documented, did you think the last forum got to 147 pages by talking about mild south-westerlies? Our weather even just after the weekend is going to be dependent on where that high sets up and thus it is relevant if the high migrates to the north-east and creates the prospect of an easterly
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I do sometimes question my own and others obsession with easterlies. They often disappoint even if they make it to T0, you never know what you'll get, that awful murky easterly with snow grains, or a more drier se based flow, if you're very lucky you get the 5 star easterly with heavy snow showers driven in on a biting wind. They take an age to get agreed on in the models and often implode.
If they're part of the lovely retrogression type with Greenland block and rinse and repeat much like the Dec 2010 pattern, indeed then the easterlies disappointed because the models were slow to retrogress the pattern but at least you knew that even if the snow showers window was short you'd have a northerly to look forward to and not one that was gone in the blink of an eye like most northerlies we see without Greenland blocking.
But yet for some reason I just can't resist obsessing over them! At the moment realistically given the upstream pattern and where the PV is expected to set up then the only way to get some real cold into the UK is from the east or ne, any other route really does require a team of Hollywood script writers.The trend for troughing in the mid Atlantic is there across all the outputs, we'll have to see over the next few days whether the Scandi high trend develops further.
Well, surely IMBYism comes into play. Most people on this forum are English and most of those are southern centric, therefore Scotland would have to be buried in snow in order for Portsmouth to get a dusting from a northerly 9/10. Thus, those in the South-east will obviously prefer the easterly. Not only are you looking at a less reliable way of getting cold into the UK than a northerly with a Greenland block but you have now got a greater audience all intently waiting for the next frame. Resulting, - as you so aptly put- in casualties with a lot more than toys and prams being thrown in this forum
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GFS 06z finishes with the beginnings of an Eastern promise. The 00z and 06z share similar evolutions through much of the runs, with varying degrees of differences post cold shot this thur/fri. HP looks set to be in and around Europe as we approach Xmas going on trends. the position of said HP however will determine whether we get a green or white xmas.
The ECM has a lovely Scandi ridge by 240 which (if it came off) would send this community into meltdown and t minus 24 hours.
I can honestly say compared to last year, this is quite exciting. Last December was an Atlantic rinse repeat situation on the models. This year however, is far more exciting to watch and far less predictable.
Exactly, unlike winters of circa 10 years ago we are not sitting here in February, still snowless and looking at week two for inspiration. This is only the second day of winter proper, with a northerly blast imminent and the rumblings of a more substantial cold spell a possibility. I wonder how long this optimism will last... probably until the next t72 shortwave spoiler!
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Scotland Regional Discussion - 29/11/2013 ---->
in Regional
Posted
Well, it is supported by stratospheric charts, the MetO and i'd be shocked if the ECM ensembles don't show it as an outliner, the UKMO (although only to 144) and the GFS doesn't count. Obviously, it is imaginary as it is only on a computer screen at 10-15 day timeframes as opposed to howling against your windows.
I do agree, that we will be going through a mild phase and it could be of longer than a week but in december that is not unusual. What is unusual is to not have that mildness supported by copious amounts of rain