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Model output discussion - into 2018


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19 minutes ago, nick sussex said:

Interesting spreads on the ECM ensembles .  For the timeframes involved T120hrs and T144hrs that’s unusually large both to the south and north of the UK and that continues well into the run.

Ecm has been consistent in having a low spread on the lw trough through n Scotland and extending se into Europe - in line with the ens mean 

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An ode to the model output thread... "In days of old, when Thatcher was bold and Kettley was a weatherman, Tales are told of winters cold, and snow lay everywhere, man.   The World Wide Web

We should rename thread the ‘miserable git’ thread -  So much negativity & misery in here I’m surprised people even make it out of bed. updated 06z JMA joins the euro party to 84

Find 1 post that I said it would be a convective Easterly - The problem with you ( & many others ) is you read one thing but assume another. The forecast was a blend of the GEM / ECM 

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2 minutes ago, bluearmy said:

Ecm has been consistent in having a low spread on the lw trough through n Scotland and extending se into Europe - in line with the ens mean 

The spread is the largest to the south and north at T144 hrs. So the mean might show agreement but there’s obviously solutions which vary quite widely.

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38 minutes ago, nick sussex said:

Interesting spreads on the ECM ensembles .  For the timeframes involved T120hrs and T144hrs that’s unusually large both to the south and north of the UK and that continues well into the run.

Do you have access to the ensemble? From the de Bilt plume I can see there finally is little uncertainty until Sunday 

Screenshot_20180109-212942.png

Screenshot_20180109-213214.png

Edited by ArHu3
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Evening everyone! The no mans land of weather continues for a few days yet, but the signal is fairly strong for a breakthrough from the Atlantic. However , some very cold air spilling towards the uk from Northwesterly winds carrying some very cold Artic air as we move into next week, plenty of potential for snow and not just on high ground. As always the devil will be in the detail but some very interesting weather to come by the time we hit next week....:cold:

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The two big beasts were 1956 and 1987 which both barged in without a by your leave. Doing the arithmetic the next one is due anytime soon. Where is Law of Averages? Just for fun the 56 as it arrived is shown below.

Returning to the present the ECM mean has been trending colder in the later reaches and we should extract something of interest for those of us of a cold persuasion. To use a sporting analogy at least we are on the fairway this winter after several years stuck in the club house.?

77B374B5-D34F-4EF3-A8D7-386CA18C8B69.png

F5AD514A-068E-402E-9FF9-7B6D7BB154FD.png

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Keep an eye on the ensembles rather than get too hung up on every operational run, which beyond the 120 hr timeframe should all come with a health warning. The ensembles for both GFS and ECM are showing an airstream from between west and north dominating next week, and more NW-N than WNW.

The GFS is showing a more pronounced NW polar airstream next week, thanks to the Azores high deflected further west, than is being shown by ECM, but that is just commenting on tonights models.

I do rate the GFS above the ECM when it comes to developments to our NW, the ECM tends to do better with developments to our east, indeed it and more so the UKMO are performing better at the moment holding the atlantic at bay when compared with the GFS which as ever has been too quick in trying to bring it back in, recent runs have seen it having to take a further backtrack, with Sunday now being the day when it makes a proper concerted attack. 

Main things to watch over the coming days, position of the jetstream, strength and position of height/ridge development over NE/E USA seaboard and crucially where the azores high decides to position itself, for those wanting a more potent NW blast and chance of height development to our NE as we enter the latter part of the month, will want to see the azores high deflected as far away as possible to the west and north west from its usual winter home - there are strong signals from GFS this will happen, but of the ECM output tonight comes off it will be much more harder for this to happen - but its just one run folks!

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6 minutes ago, Weathervane said:

The two big beasts were 1956 and 1987 which both barged in without a by your leave. Doing the arithmetic the next one is due anytime soon. Where is Law of Averages? Just for fun the 56 as it arrived is shown below.

Returning to the present the ECM mean has been trending colder in the later reaches and we should extract something of interest for those of us of a cold persuasion. To use a sporting analogy at least we are on the fairway this winter after several years stuck in the club house.?

77B374B5-D34F-4EF3-A8D7-386CA18C8B69.png

F5AD514A-068E-402E-9FF9-7B6D7BB154FD.png

A Great post , Im going to do when a get five minutes  or perhaps Five hours a post on how many Easterlies which have delivered in the last 70 years , its your viewing coming very soon:cold::cold::gathering:

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12 minutes ago, feb1991blizzard said:

Nothing iconic to open the 18z output I'm afraid.

iconnh-0-123_pdw6.png

however, the ICON..... :D

edit- i thought you were posting the GFS...

I'll get me coat....

Edited by bobbydog
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2 minutes ago, Paul_1978 said:

Feb1991blizzard downbeat? Never. 

Paul_1978 just questioning / commenting on other peoples posts with words like evidence?  charts?   and not posting anything up himself?  Never :D:laugh:

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The ecm debilt ens are disappointing compared to the last couple of runs. More mild runs in the extended. We do not want this to become a trend so we need the cold runs to return on the 00z run. 

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3 minutes ago, Catacol said:

Evening all

Model no man's land - and waiting game in full flow. 2 - 3 more days of blah output and then maybe a change to something better gradually appearing at T+240 in NWP.

Today's GFS filtered V200 forecast for the MJO is one we want to see come to fruition. Note the current week's situation: MJO in the IO and facing powerful trade winds in the central pacific. Crouch-bind-set.. as the front rows come together and prepare for battle. But 2 weeks on - and the westerly surge from the Indian Ocean has driven the trades back... stolen the ball and the No 8 has picked and gone down the blind side...opposition defenders in scramble mode. That bottom image shows a strong progression and movement towards that crucial 7/8 orbit which is highly desirable and on course for early Feb. In the meantime for Jan the surge in pacific convection on the back of these westerlies at the equator will fire up Rossby action, open the door for additional mountain torque, and provide increased amplification at higher latitudes to get the atlantic trough to dig further south.

twc_globe_mjo_vp200.png

It is, of course, only another model forecast... but the cpc are in line and current data with logical progression cycles would suggest it is on the money. Nothing is ever 100% certain - remember the disappointing fail at xmas once again (a salient reminder never to get too certain of any particular evolution) - but plenty to look forward to while we work through this current stalemate and flat atlantic trajectory.

Mmm! Your first sentence states a few days of dross before seeing anything at 10 days. However, your post of last night stated a good chance of seeing interesting day 10 charts in the next few days. Does this change equate to just a small delay? Or us it a little like the models which consistently put back any wintry weather so it always stays at plus 10 days out? 

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8 minutes ago, johnholmes said:

Well I have to say that unless my reading of the upper air charts is up the spout then I cannot see the block so often mentioned becoming the main player from the weekend on.

Looking at the last output from UK Met, not their Fax charts but their 500 mb model output. This shows the trough, currently from SE Greenland to off the NW coast of Iberia. 48 hours later, Monday 15 January it is shown from about the same place to being right over the UK, with some weak extension into the Mediterranean between Spain and Italy.

Taking the latest NOAA output and trying to compare how it is dealing with the main trough. On Sunday the 6-10 day chart showed the trough, not sure it is even the same, was from about the same NW position down over the UK and into Europe and on to the Mediterranean. Looking at that this evening and the trough has been moved east, roughly west to east Greenland to Iceland and thence down the N Sea and into Europe.

Taking the upper ridge and its surface feature, neither UK Met nor NOAA, in my view, to be near enough to the UK to have an impact greater than what I've indicated above. The issue is quite finely balanced but in the period 15-20 January I cannot see how this upper ridge can become the dominant upper air feature for the UK. What happens byond the 20 th and all I can use is the NOAA 8-14 and take a look at the other upper air charts from Meteociel.

Just doing that now

At 240 h GEFS ensemble has a large -ve anomaly down towards Turkey with +ve anoamlies north of 60 N across to Greenland and then SE towards SE Iberia and N Africa. The ECMWF 500 mb anomaly charts starts off with the +ve heights about close enough to be having some impact on UK weather (which it is doing) to being fairly similar to the GEFS or indeed NOAA. So there is nothing in the tools I use for trying to decide how the upper air pattern may evolve that makes me feel I can agree with those of you still keeping the cold block as the main player.

I have said from over a week ago that prior to weather models (1-3 day outlooks) and now with weather models (3-15 day outloos) shifting cold blocks is almost always done too quickly. In this case though the upper air pattern is not really doing that it is showing its maximum thrust jsut south of the main cold block.

Just my thoughts and links given below

http://www.meteociel.fr/modeles/ecmwf.php?ech=72&mode=101&map=0&type=0&archive=0

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

http://www.weathercharts.org/ukmomslp.htm

john, the tools you should be using are sheer willpower, 'the force', telekinesis, mind-altering drugs and denial.

then we will have a raging easterly by the weekend.... :whistling:

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