Model Output Discussion - 1st February Onwards 12z--->

[Frosty.]

Well it looks like the anticyclonic outlook has gone Pete tong now, the Ecm 0z is looking increasingly unsettled from later this week onwards.

[seaside 60]

What's fueling all the storms - insanely warm oceans.

 

A quick question if you dont mind,  what is causing the higher temps (anomalies) of the north east coast of the US, Canada and even Greenland, esp as they have had some pretty cold weather this winter.

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS

THE CURRENT GENERAL SITUATION A High pressure area near the South coast of Ireland will drift slowly East into Southern England later tomorrow with a light WSW flow over the North of the UK persisting.

http://www.wetterzentrale.de/pics/Rtavn001.gif

MODELS-2 WEEK HEADLINE Dry at first and again later with a short unsettled spell late this week and over the weekend.

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream Ensemble Forecast shows the flow blowing North of the UK currently where it remains for three or four more days. Late in the week the flow dips sharply South to the West of the UK feeding a Southern arm over Spain. This undulating pattern then moves East and remains for a while before the Southern arm becomes disengaged from a stronger Northern arm North of the UK late in the period.

http://www.netweather.tv/index.cgi?action=jetstream

GFS OPERATIONAL The GFS operational today is rather different than yesterday in as much as the orientation of High pressure and how it affects the UK has been changed as the interaction of a Low pressure trough sliding SE over the UK on Friday and then filling in situ sets up High pressure over Europe which then builds back from the East at times through Week 2 and gradually brings the risk of colder weather back across the UK from the SE or East. The run then ends with High pressure to the Northeast of the UK with a fresh and cold SE flow across the UK. A lot of dry weather is likely but a period mid run of rain at times starting Friday may last in the South until the start of next week.

http://www.wetterzentrale.de/pics/Rtavn1441.gif

http://www.wetterzentrale.de/pics/Rtavn3841.gif
 
THE GFS CONTROL The GFS control run shows a watered down version of the operational with less command from High pressure over Europe and slightly further South cutting off any continental feed. It does show the unsettled and wet period for this weekend as low pressure slips SE down over the UK and then fils it slowly by early next week. thereafter slack High pressure looks like it would bring quiet and benign conditions back across the UK with just occasional rain under westerly winds in the far North.

THE GFS CLUSTERS The GFS Clusters today show almost blanket coverage of High pressure expecting to lies to the South or SW of the UK with a West or NW flow across the UK. there are varying degree of proximity to the UK of the High with at least a 35% spread keeping it close in to the UK and maintaining largely dry and benign weather over the South at least.

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cpre&HH=372&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

UKMO UKMO this morning shows Low pressure moving into the UK late this week replacing the receding High pressure away East up to that point. Then over the weekend the Low fills and moves away South leading to a slack SW flow and another trough easing in from the West by the end of the weekend.

http://www.wetterzentrale.de/pics/Rukm1441.gif

THE FAX CHARTS The Fax Charts this morning show High pressure declining away to the East through this week leaving slack winds behind until the end of the week which shows Low pressure and associated troughs edging into the West of the UK by the weekend.

http://www.weathercharts.org/ukmomslp.htm#t120.

GEM GEM shows a more mobile evolution developing later next week and beyond as the High pressure currently covering the UK moves away East into Europe and declines. The marked trough at the end of this week is shown here as well with rain and wind for all for a time. As this fills and dissolves away South a more mobile Westerly flow gradually develops with further troughs affecting the North at first and gradually more areas too by the end of the period as the Westerly flow strengthens

http://www.wetterzentrale.de/pics/Rgem2401.gif

NAVGEM NAVGEM differs to the rest from the end of the week in that it doesn't disrupt the trough South and hilds it's parent depression North of the UK leading to a trough crossing East with a spell of rain followed by a more mobile Westerly flow developing for the start of next week with stronger Westerly winds and rain at times gradually extending from the NW to all areas with time.

http://www.wetterzentrale.de/pics/Rnvg1681.gif.

ECM ECM shows a deterioration in conditions later this week as it too shows High pressure moving away East and slowly strengthening the winds later as the Low slips SE to the West of the UK with some rain over the weekend. then as that Low declines a strengthening Westerly flow over the Atlantic could give a rinse and repeat pattern of the rain this coming weekend before a more mobile Atlantic Westerly takes more influence over the UK by Day 10.

http://www.wetterzentrale.de/pics/Recm2401.gif

ECM 10 DAY MEAN The 10 Day Mean this morning maintains the prospect that pressure is biased lower to the North of the UK and higher to the South and SW. The main belt of High pressure from the Azores to France should bathe the UK in mild Westerly winds and with some rain at times in the windier North.

http://www.wetterzentrale.de/pics/Reem2401.gif

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The long term trend today remains for High pressure to be in relative control likely positioned to the South of the UK but with some discrepancies between models in how much control it may hold across the UK this morning.

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKM & ECM The current verification statistics for the past 31 days shows ECM leading the way at 3 days with 97.5 pts followed by UKM at 97.0 pts and GFS at 96.2. At 5 days ECM just about leads the field at 89.9 pts over UKMO at 89.1 pts and GFS at 87.0. At 8 days GFS takes over with 62.9 pts over ECM's 62.3 pts. Then at Day 10 ECM regains superiority at 46.9 pts over GFS at 45.3.

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.prig
 

MY THOUGHTS All models continue to show reasonable weather this week as High pressure slips across the UK and away to the East later this week. In it's wake will be a spell of slack winds and benign conditions before winds strengthen from the SW towards the weekend and Low pressure slips SE down over or just to the West of the UK with some rain for all come the weekend. It's then that the models begin to differ somewhat as they fill this depression up and dissolve it away South early next week. While this filling Low takes place a spell of cloudy rather cold weather is probable with a little rain at first before the majority of output brings High pressure back again. The central positioning of this High is crucial as to how things will be at the surface with the GFS operational in particular slowly setting up a colder period again as High pressure to the East gradually fuels a new High towards Scandinavia by the end of it's run though this is not well supported within it's own ensemble pack. Instead they show much like the rest of the models that High pressure is likely to rebuild close to the South or SW of the UK with a Westerly flow across the UK with some rain at times in the North. The main differences between output then is the likely influence or not that Westerly flow has on Southern Britain with a split share bringing unsettled weather into the South too at times. So all in all changeable weather is likely over the two weeks with a little rain for all and a lot of dry and quiet conditions too. Temperatures look like being near to average or above in sheltered Eastern parts should the later Westerly flow develop and unless the GFS operational comes to fruition then there seems little chance of anything remarkably cold, wet or wintry over the period for anyone.  

Issued at 08:30 Monday February 9th 2015

[knocker]

A quick question if you dont mind,  what is causing the higher temps (anomalies) of the north east coast of the US, Canada and even Greenland, esp as they have had some pretty cold weather this winter.

 

I don't mind in the slightest but I'll have to phone a friend. On a more serious note this may be of interest.

 

Recent Warming of the Labrador Sea

 

http://www.meds-sdmm.dfo-mpo.gc.ca/isdm-gdsi/azmp-pmza/docs/bulletin_5_04.pdf

[Interitus]

A quick question if you dont mind,  what is causing the higher temps (anomalies) of the north east coast of the US, Canada and even Greenland, esp as they have had some pretty cold weather this winter.

 

A degree of caution must be used when looking at the SST anomalies in places where the climatology (the CFSR 1979-2000 baseline in this case) has usually ice.

Open water here shows as the strong anomalies in the Newfoundland/Baffin seas from Canada to Greenland, and elsewhere round the icepack edge such as the Barents, Bering and Okhotsk areas.

Why the particular distribution of temperatures in the open Atlantic I don't know, but it is not just determined by recent weather but the conditions and circulation for several months.

[karyo]

A quick question if you dont mind,  what is causing the higher temps (anomalies) of the north east coast of the US, Canada and even Greenland, esp as they have had some pretty cold weather this winter.

The fact that our planet just had the warmest year on record must have played its part.

[Frosty.]

Good agreement from the GEFS 0z for the northern arm of the jet to flex it's muscles, I think Ian Brown would love this set up. This suggests a nw / se split eventually becoming established with the north and north west of the UK becoming predominantly unsettled but high pressure close to the south or south west bringing more in the way of fine weather to the south of the UK between weather systems.

[seaside 60]

Dam long reading link Knocker gave lol..

I also note that its ten years old, due to timing of last survey, its cyclical it seems like most things in nature.

It was more not so much in the far north east, but it starts virtually from the Florida coastline and runs up the whole coastline.

[mushymanrob]

No that is the point, more often than not.

 

Unless we are in a locked in pattern of south westerlies or a dominant zonal pattern, charts past day 4/5/6 are always open to changes, however some people treat a more blocked pattern as they would a zonal pattern and sometimes can put to much faith in the mid term charts.

 

When the pattern is not a straightforward prevailing type then more scepticism needs to me placed in the mid term. The Low at the end of the week is a good example, and alas those winter is over posts are premature. 

 

im more confused then ever now...... the poster i quoted agrees with your summary that agrees with my question, so how can it be both a 'debacle' and 'open to changes'?....

anyway..

interesting that the current outputs suggest the 'end of week trough' might be a greater feature then they did yesterday, and open up a slightly more mobile picture next week, (as opposed to a quick return to high pressure dominance previously suggested). the anomaly charts though dont really support much in the way of mobility for the southern half of the uk

 

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

with high pressure close to our southwest.  so a return to a more high pressure dominated outlook then mobile one will resurface in future runs?

 

[seaside 60]

The fact that our planet just had the warmest year on record must have played its part.

Apart from the fact that most of the Atlantic is showing a colder anomaly.

[knocker]

Quite a good link for sea data

 

http://www.nnvl.noaa.gov/view/#SSTA

[summer blizzard]

Ensembles still bullish from day 9 but this is all very depressing before then..

 

[IDO]

 

The GFS op is still playing with next weekends LP and though it looks like it will bring some unsettled weather to all, on the 06z it remains a blip for the south. Further fronts after D7 will bring wet weather to the NW/W but weaken before they reach the SE. It now looks like the next HP system after D8 is mobile rather than the current blocked one, so we have the Atlantic running to the north and the ridge to the south. Again the overall output till around D15 is that scenario, one which has been well sign posted, though has varied at times. At D16 the PV is beginning to look stretched and a bit more docile so the last few days of Feb into March may hint at something more blocked popping up:

 

Edited February 9, 2015 by IDO

[TEITS]

Model output continues to bore me.

 

I have to be honest even the GFS attempts at an E,ly flow do nothing for me. When it comes to a classic E,ly the synoptics prior to this developing are just as important as the actual synoptics that bring the E,ly. I shall explain this below with some archives.

 

Take this chart below from Feb 1991 which shows the Scandi HP in the perfect position and the corresponding upper temps.

 

http://www.wetterzentrale.de/pics/archive/ra/1991/Rrea00119910207.gif

http://www.wetterzentrale.de/pics/archive/ra/1991/Rrea00219910207.gif

 

However do get into this position you need to rewind back many days. Look at the chart below and you will see the very cold airmass sinking S.

 

http://www.wetterzentrale.de/pics/archive/ra/1991/Rrea00119910129.gif

http://www.wetterzentrale.de/pics/archive/ra/1991/Rrea00119910130.gif

 

So basically when the HP orientates itself into the perfect position for the UK it has the colder upper temp airmass to tap into. The Jan 87 E,ly is an even better example of this.

 

http://www.wetterzentrale.de/pics/archive/ra/1987/Rrea00119870109.gif

 

Sadly I am still awaiting a classic E,ly even after all these years of being a member on this forum. It seems not only do we fail to get a Scandi HP in the correct position but we neither get that cold pool sinking S to tap into anyway.

Edited February 9, 2015 by TEITS

[Nouska]

A degree of caution must be used when looking at the SST anomalies in places where the climatology (the CFSR 1979-2000 baseline in this case) has usually ice.

Open water here shows as the strong anomalies in the Newfoundland/Baffin seas from Canada to Greenland, and elsewhere round the icepack edge such as the Barents, Bering and Okhotsk areas.

Why the particular distribution of temperatures in the open Atlantic I don't know, but it is not just determined by recent weather but the conditions and circulation for several months.

 

The more recent climatology of the Environment Canada SST anomaly map shows this I think.

 

 

Just a thought - could the lack of coast hugging hurricanes, over the last two seasons, have the effect of not mixing out the warmth of the gulf stream?

 

A good site for analysis of the oceans and ice.  http://bulletin.mercator-ocean.fr/fr/PSY4#2/69.7/-51.3

[492]

Model output continues to bore me.

 

I have to be honest even the GFS attempts at an E,ly flow do nothing for me. When it comes to a classic E,ly the synoptics prior to this developing are just as important as the actual synoptics that bring the E,ly. I shall explain this below with some archives.

 

Take this chart below from Feb 1991 which shows the Scandi HP in the perfect position and the corresponding upper temps.

 

http://www.wetterzentrale.de/pics/archive/ra/1991/Rrea00119910207.gif

http://www.wetterzentrale.de/pics/archive/ra/1991/Rrea00219910207.gif

 

However do get into this position you need to rewind back many days. Look at the chart below and you will see the very cold airmass sinking S.

 

http://www.wetterzentrale.de/pics/archive/ra/1991/Rrea00119910129.gif

http://www.wetterzentrale.de/pics/archive/ra/1991/Rrea00119910130.gif

 

So basically when the HP orientates itself into the perfect position for the UK it has the colder upper temp airmass to tap into. The Jan 87 E,ly is an even better example of this.

 

http://www.wetterzentrale.de/pics/archive/ra/1987/Rrea00119870109.gif

 

Sadly I am still awaiting a classic E,ly even after all these years of being a member on this forum. It seems not only do we fail to get a Scandi HP in the correct position but we neither get that cold pool sinking S to tap into anyway.

http://www.meteociel.fr/modeles/archives/archives.php?day=25&month=1&hour=0&year=2012&map=0&mode=2

Not so very different to what GFS is modelling this week and this spell was only 3 years ago. It ended up in early February with the SE of the UK coming under the influence of proper Siberian air one of the few occasions in the last hundred years or so.  

Edited February 9, 2015 by 492

[seaside 60]

Quite a good link for sea data

 

http://www.nnvl.noaa.gov/view/#SSTA

That's a much better overall view compared to others. Thanks.

Also shows a large area of warmer water north of the Norwegian Coast as well.

[Frosty.]

6z saved the best until last, for Scotland anyway.. looking at the run overall, our generally cloudy high hangs around until Friday before being replaced by Atlantic low pressure, the northern arm of the jet appears to be firing up and pressure eventually rises to the SE so we end up with a nw / se split with the best of the weather in the south. This being the fag end of winter, my thoughts are now on spring.

[carinthian]

Afternoon from a snowy Austria. Just for a bit of fun to break up the rather uninspiring forecast models for the UK at the moment. Can you readers of the various models predict the temperature and surface wind flow at Gatwick Airport for (12Z) Tuesday 17th February 2015? You may remember a couple of weeks ago, I was going for a Easterly by then. More than likely off the mark, but I will stick with my prognosis and predict 3C and ENE. Remenber the models from a few days ago had a pressure of 1040mb over the UK for the end of this week, could be 35 mb lower in places now !

Will be interesting to see some of your various interpretations of your model assessments for this date. Good luck.

C

Edited February 9, 2015 by carinthian

[Interitus]

Can you readers of the various models predict the temperature and surface wind flow at Gatwick Airport for (12Z) Thursday 17th February 2015? 

C

 

No because 17th is a Tuesday, for which I predict pancakes with lashings of golden syrup!

[bluearmy]

Poor confidence in the NWP remains imo.

Not worth commenting that the extended eps continue to show low anomoly dropping in for the back end of feb.

It might be here a week earlier than that (or not at all!)

[Captain Shortwave]

Poor confidence in the NWP remains imo.

Not worth commenting that the extended eps continue to show low anomoly dropping in for the back end of feb.

It might be here a week earlier than that (or not at all!)

Not exactly oozing confidence when we have huge discrepancies at 4 days out.

UKMO drops the low south east west of the UK.

 

The GFS on the other hand flips this run and drives the low eastwards through Scotland. 

The GFS looks changeable from the end of the week whilst the UKMO develops a week ridge extending from Europe into the UK.

Edited February 9, 2015 by Captain shortwave

[carinthian]

Well, do not know what to make of this latest run. GFS and UKMO big differences as early a 144hrs. GFS has a sort of NWly flow and UKMO sort of SEly flow. Pressure distributions show major differnces on this run anyway. See what ECM produces.

C

[igloo]

this evenings UKMO chart is not to bad at +144h it may be a long shot but the HP may just move further west if it went further out those lows diving SE in to europe may be the triger to pull it west on the other hand the GFS looks nothing like it winter is not quite over yet there is still a very slim chance left

 

Edited February 9, 2015 by igloo

[IDO]

Astonishing. For midday on the 18th Feb the UK temps compared to the US:

 

 

 

Its so unusual when the US is in very cold conditions that we can get even average uppers let alone a cold pool. I suppose we have to be grateful as the US has had a very severe winter with more to come.

 

With the PV as it is we have to just sit it out as the NH profile gives little suggestion that cold is incoming to the UK:

 

 

Anyway GEM and UKMO are sort of on the same track with HP in charge till Friday then by D6 attempts to ridge in from the SW:

 

 

 

GEM then has another small scale trough edge south around D7 before the Azores ridges NE by D8 and that marries with the GFS at that time:

 

GEM:   GFS: 

 

GFS op continues with its theme of HP from D8-D12 (plus):

 

D12:  D16: 

 

After D13 the upper trough is leaving the Conus so that ties in with the potential for change in the Atlantic, with at least some very cold 850s being sent packing from the US:

 

 

That happened in the last cold spell in America so plausible.

 

 

Edited February 9, 2015 by IDO