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Model output discussion 25th Jan onwards

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The last two posts from Purga and Phil nw totally contradict each other. One is sating no sight at all of anything wintry and the other is saying chance of widespread snow. For anyone coming on here to check what the models are showing its difficult to know what the hell is going on. Who do you believe, how can you get completely different outcomes

It's just differing views John-no harm in that.It will be marginal anyway and as WH said more probable over higher ground.

 

Don't wish to overplay the snow but there is a possibility for some but we can never be sure as John H.often says so many variables and forecasting snow more than 24 hrs ahead is fraught with uncertainty.

All we can do is monitor this- doubtless things will change as we get closer.

Edited by phil nw.

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The last two posts from Purga and Phil nw totally contradict each other. One is sating no sight at all of anything wintry and the other is saying chance of widespread snow. For anyone coming on here to check what the models are showing its difficult to know what the hell is going on. Who do you believe, how can you get completely different outcomes

 

 

That's the essence of a forum, differing opinions!! 

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shh - purga will be reading this .................................

lol!!im sure he wont disagree........

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I think with a strong westerly flow that despite decent low 850hPa temps there is so much surface mixing and flow off a mild sea that any wintry precipitation is likely to be veor ginal and confined only to the highest hills / mountains.

 

Anyway if a sleety mix were to ensue it would be extremely brief as ECM shows a powerful mild pulse blasting in

Posted Image

Posted Image

Wet & mild more likely at +240hrs

Purga you showed a chart from +T196 then +T240? From what I see the potential (and it is just that) was +T96/120. Bit misleading then to show much later FI charts? Are we are talking about a transitory event on Tue/Weds 4/5 days away or 8-10 days? As I see the spreads fairly aligned until the ~10th this is (current) deep FI you are using to compare? What period do you mean?

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So still a real mix of "will there be a storm, won't there be a storm" for middle of next week: UKMO has severe gales next Tuesday, GFS has severe gales/storm for western areas on Wednesday, and ECM has a smaller storm now running completely to our south. GEFS has quite a range of storm possibilities for next Tuesday-Thursday with probably 50% having a nasty direct hit somewhere in the UK: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=120. It will be T72 before this one firms up, I suspect.

 

 

... meanwhile, back on topic, GEFS ensemble member 12 looking good for snow on 23rd February ;)

 

Posted Image

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Wind, rain and more wind and rain looks the order of the day, but with plenty of uncertainty as to what and where. So FI for us is really short, from Tue onwards there is still much to be decided in regards the pressure pattern. Unfortunately there is still little signs of cold, except the GFS, which from late mid range at least try’s to introduce some HP and thus a chance to dry out and cool off somewhat. I will however, be very surprised if the 18z follows suit.

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That's the essence of a forum, differing opinions!! 

 

True Chris, and I am certainly NOT getting at you here as it's a broader message to all. I come onto the MOD to read and sometimes re-read the excellent analyses given by some long standing NW members, in order to find out what the future weather is forecast to be. I don't come on here to hear constant references to people who aren't able to post without bigging up themselves or equally belittling someone else's opinion. I am here to learn about the forthcoming prospects and not to listen to antics which are better placed in a primary school playground. The two persons (referred to several times already) are welcome to their own opinions as are all folk and for the not so informed, you simply learn over time who to trust and who not too. IF a certain couple of members has a beef with each other, don't bring it out into the public domain. Many Thanks and god bless those whom are not enjoying this current spell of inclement weather, my thoughts are with you. Posted Image

Edited by gottolovethisweather

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purga is just having a laugh. the facts are that the op 12z ecm brings lying snow to se england. (ironically mostly where purga is). the issue here is that we are yet to pin down the track of this sytstem or even if the depression will actually exist as as a closed low at all.

 

there are a few chances of snow fall next week over the uk, especially further north and over hills but the main story will be likely be flooding and gales. the ecm op is continuing to trend less low heights in its unreliable timeframe to the point that eventually the ens will have to go with it.

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Purga you showed a chart from +T196 then +T240? From what I see the potential (and it is just that) was +T96/120. Bit misleading then to show much later FI charts? Are we are talking about a transitory event on Tue/Weds 4/5 days away or 8-10 days? As I see the spreads fairly aligned until the ~10th this is (current) deep FI you are using to compare? What period do you mean?

Hi WM, the last 2 charts I showed were both the +T240's one being the 500hPa and the other the 850hPa. It was done to illustrate what I think will be a very brief / transitory period of possible wintry precipitation in favoured upland ares in the north of the country. The two charts indicate that ECM models a quick transition to milder conditions following on from any minor wintry interlude. It's a matter of interpretation of course and any one of us can be right or wrong with our personal forecasts.

My main point is that I don't expect to see any significant or 'widespread' snow next week as such a phrase tends to indicate something much more exciting than is likely to occur - especially when folk who are new to model / weather watching could easily read too much into such phraseology.

Fingers crossed that there will be some decent snow for all this winter, it's just that I honestly can't see it anytime soon and haven't for many long weeks sadly.

If there is a credible and consistant signal for cold snowy weather backed up by METO then believe me I will ramp like hell with the best of 'em. Posted Image

 

 

EDIT: BA I hadn't read your post - please read what I've just written before jumping to conclusions about my motives. Posted Image

Edited by Purga

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Good evening. Here is the report on the midday outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Friday February 7th 2014.
 
All models show a very deep depression approaching Ireland from the West tonight and carrying a set of fronts East across the UK with attendant heavy rain and increasingly strong winds. the rain will scoot through quite quickly so despite the rain being heavy it shouldn't last too long before clearer and showery weather follows well before dawn. Tomorrow shows a deep Low across Northern Ireland with severe gales and squally showers, perhaps with hail and thunder and snow on Northern hills. Through Sunday the storm system will move North and fill slowly with less windy but still showery weather which may well last into Monday too.  By Tuesday a new storm system will be rattling in from the SW with further gales and heavy rain by midweek.
 
GFS tonight then shows the rest of next week and weekend as further deep Low pressure areas spread wind and rain across the weekend on regular occasions, heavy at times and with strong winds too. In the low resolution part of the run though improvements do manifest themselves in the shape of a rare visitor to our shores of late known as High pressure which would bring a long awaited dry spells with the emphasis shifting from wind and rain to frost and fog with some sunshine by day.
 
The GFS Ensembles still show a good deal of unsettled and windy weather to come but the best indication yet of some relief late in the run to something drier and brighter with less rainfall and wind.
 
UKMO tonight shows another deep Low nearing NW Ireland next Thursday with yet more wind and rain spreading steadily North and East across the UK next Thursday with the likelihood of showers and blustery West winds soon after.
 
GEM tonight shows further wet and windy spells in association with further Low pressure later next week and the weekend with winds slowly becoming lighter with time.
 
NAVGEM closes next Friday with deep Low pressure over the UK with further rain at times, heavy and prolonged in places though probably with winds less strong.
 
ECM does show some changes tonight as it moderates the depth of depressions next week and eventually rises pressure over Europe. The question is will it bring better weather for those areas that most need it and I think the answer is probably No. The rise in pressure to the SE eventually brings the prospect of warm moist air travelling North towards SW Britain and with Low pressure close by to the West heavy rain is still likely towards these areas.
 
The ECM 9 and 10 Day Mean Charts indicate little overall change to the basic pattern of Low pressure being up to the Nprth and NW with a SW flow likely over the UK with further rain at times in temperatures close to the seasonal average.
 
 
The GFS Jet Stream Summary shows some signs of moving through Week 2 as it buckles and ridges Northwards at times disrupting the pattern of successive Low pressure areas moving East with fine interludes in between.
 
In Summary tonight although the prospects are still well biased towards unsettled conditions continuing the very worst of the conditions may begin to ease as time passes over the second half of the output tonight. So after some more heavy rain and strong winds further rain at times is likely too later on though with time longer drier periods may begin to develop with rainfall less persistent than of late. Temperatures still do not look like straying far from the seasonal average with no more than hill snow possibilities in the North.

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With so many options on show in the ECM postage stamps at T120hrs its very hard to have too much faith in the ECM operational run in terms of that runner low. You can also see a wide spread in terms of how much cold is over the UK at that time.

 

http://www.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2014020712!!/

 

There is a chance if the ECM operational run is closer to the mark to see some snow on the northern flank of the low that zips through between T96 and T120hrs.

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Am I allowed to say there are loads of people looking through the various models at the moment who really gave up giving a monkey's about any sort of cold weather...unless it's dry! The usual entertainment value of find the cold spell left on a bus of desperation a couple of weeks ago....now I'm just looking for a period of weather when I'm and hundreds of others are not having to dry out walls and floors twice a week. It is getting scary now. I just want to bring a reality check to some.

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With so many options on show in the ECM postage stamps at T120hrs its very hard to have too much faith in the ECM operational run in terms of that runner low. You can also see a wide spread in terms of how much cold is over the UK at that time.

 

http://www.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2014020712!!/

 

There is a chance if the ECM operational run is closer to the mark to see some snow on the northern flank of the low that zips through between T96 and T120hrs.

 

Yes, with the operationals and ens varying with each run with the placement of secondary lows as early as next Tuesday next week, it's difficult to pin down any detail with regards to potential snowfall. The 12z ECM and GFS operational both suggest a wave trough and accompanying cold front sweeping east on Tuesday, with rain along it turning to snow across Wales, The Midlands and points north from there - as cold air feeding direct from NE Canada surges in behind the front. However, deepening secondary lows coming in from the SW - as suggested by UKMO and some EC and GFS ens, would complicate this cold surge by delaying it somewhat. 

 

I'm actually having more faith in the GFS operationals atm, as ECM keeps chopping and changing with placements of low pressure around t+96 to T+120. UKMO seems a bit volatile too and is unusually developmental this evening, with its very deep low coming into across Ireland at t+96. GFS seems to be the most consistent .. for now.

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Maybe i should clarify re.my earlier post.

 

I did say in that post "a chance of more widespread snow"-meaning more areas under consideration than has usually been the case up to now which have been mainly the Scottish Highlands.This To include other higher level regions of the UK  and i am thinking possible places lower down where the colder air undercuts behind the low bringing down freezing levels.

To confirm we are looking around the T96hrs period here and as BA alluded to we are still waiting for the models to agree on the track and development of this feature and where the colder air will react to the precipitation.

 

I just thought it was something of interest to monitor away from the usual depressing outlook of wind and rain which as i said earlier is the main theme going forward.

What a shame it is when you have to clarify a post refering to snow this winter Phil.Some will think that snow will only fall on mountain tops, that live in lowland southern areas,which is not the case.Altitude above 150mts is common in Northern England and as such snow next week could be widespread up here.Such is the topography of our little Island.

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ECM 12z Anomalies chart N Hem at 240 hours show the complete retreat of the Aleutian high. PV still strong and still throwing out Low pressure systems at us mostly towards the West parts of the UK. http://www.meteociel.fr/modeles/ecmwf.php?ech=72&mode=1&map=1&type=0&archive=0

A day without rain up here sends us into shock so we can take it, 300 days a year of it, the trick is Whisky osmosis.

Good signs for the South East with a dry out from the continental High showing, but unfortunately doesn't look the same for the SW as it continues to get clipped from lows going through. Although not as severe.

Met office are right again with the split NW/SE

The pattern looks to continue in the vain of Winter 89/90.

Three days of wintery weather looking good for the start of next week.

Poor winter for snow lovers but it's a necessary evil to endure and possibly again next winter due to warm AMO phase that were in. Warm Atlantic creating so much energy as seen thus far.

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Snow event still showing on on the 18z for next week!!

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looking good!

It is looking consistant in the model output Shaky.

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looking good!

 

Those charts are very misleading, inaccurate, best looking at netweather GFS charts, which tend to suggest back edge sleet for low lying areas

 

then by tuesday night, its wintry showers from the west, with snow in usual places, highlands, scotland, high levels of west, wales

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the ecm extended are slow out on weatherbell so in the interim its worth stating that week 2 offers the chance of some amplification to our west, the like of which we havent seen for some considerable time. the canadian vortex, settling n hudsons and as expected, it becomes distracted by the developing alasakan segment.  (despite crewe's assertion that the ecm ens have been useless this winter, these are all things that the extended ecm ens have pointed to over the past week).  so far this winter, we have seen the canadian segment of vortex with a repeated lobe extended out into the n atlantic which has fed the upper trough as an extension of the vortex itself. week 2, should see this become less of an issue which will allow some atlantic ridging (remember that ?), should the pattern wish to amplify off the eastern seaboard. we do have a weak blocking structure present over greenland at that timescale anyway so its feasible that any atlantic ridge could bolster this and create some real blocking around greenland. however, that seems a step too far, given where we've been thus far. all i'm saying is dont rule it out. at the moment, i would say that any developments in this direction are more likely to lead to a west based - NAO than a cold set up for nw europe.  at least there may be some variation in the output upcoming. closer to home, it probably means the upper trough filling out slowly and the amounts of rainfall slowly easing though still an issue because of its persistance.

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