Model Output Discussion 1200 hrs 30/09/14

[gottolovethisweather]

The temporary weekend at 06Z

 

Once the temporary weekend mini-heatwave (!) is over, what will it be replaced with, that is the question. An unsettled North-westerly flow is the current favourite as I see it. Getting back to your charts, I'm imagining that first chart reflects the likely DAM readings, if so, the 528DAM is not too many hundreds of miles away from the NW of the UK. Of course, the main focus is on the potentially spell-binding heat likely in certain parts of Europe as especially well illustrated in your second chart offering.

Edited October 14, 2014 by gottolovethisweather

[Polar Maritime]

High pressure pushing North a little more on this evenings run for a day or two, Before a cool N/Wly kick's in. A very changeable but unsettled/wet outlook 

 

Edited October 14, 2014 by Polar Maritime
Charts posted wrong way round..

[IDO]

Good news from UKMO and GFS with regard to the trough getting cut off so by D6 both have the Azores ridging over the upper low promising a more settled period (less unsettled probably) for the south:

 

 

 

So by D8-D10: 

 

 

 

A lot better than recent output. I was expecting an active Atlantic flow due to the blocking high over the US conus that was diverting the jet towards the UK. The cut off low may prevent that. By D11 we still have the block over the US:

 

 

I suspect that the settled period (if it happens like this) will therefore only be a temporary respite, with the LP systems from the NW gradually overriding the cut off low. GEM shows how the cut off may not be quite enough to benefit the south compared to the GFS, D7 GEM:

 

Edited October 14, 2014 by i'm dreaming of...

[gottolovethisweather]

High pressure pushing North a little more on this evenings run for a day or two, Before a cool N/Wly kick's in. A very changeable but unsettled/wet outlook 

 

 

Yes PM, the GFS 12z run looks even more variable than before with all options firmly on the table. I think the potential undercutting trough caught up in the Jetstream, which moves in a NW-SE direction towards the UK around the 20th and 21st October timeframe is bringing about much uncertainty as what happens thereafter. In other words, I think this latest run may be hinting at ex-Hurricane Gonzalo getting involved and if so, the key timeframe has to be what is likely to develop next weekend and into the final the week of October. Certainly looks worth a heads-up for a NW type airstream over the UK by that stage as long as the Azores High stays in the actual Azores. First hint at proper wintry precipitation in the highlands right then and apparent on a number of other outputs of late although I would predict the chances of such an outcome as no more than 30 to 40 percent likelihood right now. More runs needed but the 26th and 28th October are both dates to watch in my opinion.

Edited October 14, 2014 by gottolovethisweather

[knocker]

The travels of Gonzalo

Edited October 14, 2014 by knocker

[Cloud 10]

Ensemble means from GFS,ECM and GEM looking very seasonal as we head towards mid-October with the Atlantic trough running the show,so bouts of wind and rain likely with temperatures around average.

 

gens-21-1-240 (1).pngEDM1-240.GIFgens-21-1-240.png

 

Just thought i would re-visit this post from the start of the month where the ensemble means were in very good agreement on the expected pattern for today,and it seems they gave quite poor guidance compared to the actual chart.

 

 

Needless to say the op. runs were pretty clueless as well!

 

 

Just something to remember when there's blocking over the arctic,especially

with the silly season fast approaching...

[SMU]

^^ remember the models in October will slowly with Time ( out to 240 & beyond ) try to moderate any polar blocking & eventually phase out the signal all together - replacing it with a more zonal fit - in relation to the mean average. ( October being one of the most zonal months)

 

Tonight sees perhaps the beginnings of the first chilly snap from the North, the GFS has had a few stabs & now its the ECMS turn combined with the 12z GEM.

 

aside from out little patch though the signal remains for a split vortex across the pole & some significant snow build up where the lows are developing & swinging into the very cold air.

 

OPI index looks like remaining in the negative zone ( sub -1) for the next 10 days or so ...

 

S

Edited October 14, 2014 by Steve Murr

[ANYWEATHER]

The traditional October weather will continue for the rest of this week and into next. Rain and wind will be the feature right out to day ten [t~+240] But by then we may see something colder on the Arizon as the flow from the Atlantic switches from a Southwesterly  to a Northwesterly......

Edited October 14, 2014 by ANYWEATHER

[Milhouse]

We may see a northwesterly. Emphasis being on 'may'. On the GEFS mean it doesnt arrive at all. While the ECM 12z has a cooler flow for the last 3 frames and the GEM has things turning cooler right at the end at T+240h.

 

 

 

 

Above average in the reliable, returning to average later.

 

[BlueHedgehog074]

The 12Z JMA seems to want to put South-Eastern areas into the oven on Sunday...

 

 

Would be pretty incredible if something like that verified for mid-October, although probably unlikely to verify considering most other models show more of a South-Westerly feed for that day instead. As it stands, though, the weekend still looks as though it will be warm as the Low Pressure system to our West draws up warm air from the South and South-West (but probably somewhat cooler over North-Western areas with the warmest air being directed over South-Eastern parts of the UK).

Edited October 14, 2014 by DiagonalRedLine

[Man With Beard]

Just thought i would re-visit this post from the start of the month where the ensemble means were in very good agreement on the expected pattern for today,and it seems they gave quite poor guidance compared to the actual chart.

 

ECM1-0 (1).gif

 

Needless to say the op. runs were pretty clueless as well!

 

ECM1-240.gifgem-0-240.pnggfs-2014100400-0-240.png

 

Just something to remember when there's blocking over the arctic,especially

with the silly season fast approaching...

Really glad you posted this, I was thinking the very same. The models seem to trend towards more blocked conditions as T0 approaches at the moment. It was quite the opposite last year. Will be interesting to follow this for the next couple of weeks too.

[knocker]

Last evenings anomalies are again showing the usual with some adjustments that have some bearing on the surface analysis.

 

A swathe of cold air running Greenland to eastern Europe warmer air south of this running roughly west to east. But certainly an important factor the blocking HP over the US and a trough along the eastern seaboard which is a possible gate'gateway' for the trajectory of depressions which could then hit the almost zonal and static jet. I've thrown in the global 500Mb in as it gives a better perspective.

 

On the surface low pressure across the Atlantic overlying the HP and again it is the latitudinal orientation of this that will decide how unsettled the UK will be.

 

In the longer time frame differences between the GEfS and ECM have developed. some differences the ECM has got rid of the trough along the eastern seaboard and developed the HP whereas the GEFs has also developed the HP but further east with a more pronounced trough in the western Atlantic. With heights low to the north this could perhaps signal a more permanent change in the upper pattern. Time to give Gypsy Rose a ring.

 

I'm afraid the charts have loaded as the fancy took them so one cannot just whizz through them. Very annoying.

Edited October 15, 2014 by knocker

[Polar Maritime]

ECMWF showing a N/Wrly around the 25th, As is GFS.. The last few frames for Months end show a big lobe of Low Pressure pushing South strengthening the N/W flow, Taking the Jet with it. The Vortex again remains disrupted with heights over the Poles. The last 1/4 of October continues to look much cooler and unsettled.

 

Edited October 15, 2014 by Polar Maritime

[Gibby]

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY WEDNESDAY OCTOBER 15TH 2014.

 

NEXT UPDATE THURSDAY OCTOBER 16TH 08:00

 

THE CURRENT GENERAL SITUATION. An occluded front will move NE across the UK today and tonight to lie West to East over Scotland tomorrow. A very mild SSW flow will develop across England and Wales behind it.

 

MODELS-2 WEEK HEADLINE  Changeable weather with showers or longer spells of sometimes heavy rain in strong SW then West winds. A few drier and brighter interludes in near average temperatures overall.

 

THE JET STREAM ENSEMBLE FORECAST The Jet flow will continue to strengthen over the next few days and edge to a position over the UK in a strong NE flow through the coming days. It then shifts it's axis to a West to East motion still across the UK next week. Late in the period it remains quite strong though ridges North across the UK at the end of the period.

 

GFS The GFS operational today shows Atlantic based changeable weather dominant across the UK throughout it's duration this morning. The very mild but unstable SW flow over the next three to four days turns to a cooler Westerly from Sunday with next week seeing plenty of wind and rain as successive troughs and Low pressure to the North swings across the UK. Some drier and brighter periods are shown under weak and transient ridges but these seem quickly chased away by the next depression and fronts.

 

THE GFS ENSEMBLES. The GFS Ensembles support the operational in full with cooler Westerly winds with occasional gales and heavy rain dominant at frequent periods over the next 10 days. It's only at the end of the run when pressure builds North across the UK from the South bringing some relief from the Atlantic onslaught for a time especially over the South.

 

UKMO UKMO this morning shows complex Low pressure to the North of the UK and a strong Westerly flow over all parts of the UK. The weather would be very unsettled and windy with showers or longer spells of rain in temperatures having returned close to the seasonal average by early next week.

 

THE FAX CHARTS  The Fax Charts shows a very mild and strong .SW flow across the UK. there are multiple troughs crossing erratically East and quicker Northeast over the UK at times with rain and showers as a result for all. An active series of fronts moving in from the west on Sunday spell the end to the very mild air and bring fresher cooler air in from higher latitudes of the North Atlantic to start next week

.

GEM The GEM operational today shows a very mild SW flow shifting towards a cooler but equally strong Westerly flow next week. With Low pressure remaining to the North throughout the remainder of the run the weather will be wet and windy at times next week with temperatures having fallen to average levels overall.

 

NAVGEM NAVGEM indicates the same theme albeit a little slower in delivering the cooler air to the SE early next week. Nevertheless, the pattern remains unstable for all parts of the UK with rain at times and temperatures gradually declining to average levels for all as we move through next week. 

 

ECM The ECM operational today also underlines the theme shown by most output that after the deep mid Atlantic Low moves NE and away to the North at the weekend it opens the door for cooler and unstable Westerly winds to take command next week with rain at times. After some very mild values at the end of this week and start to the weekend temperatures will fall off to average next week in a blustery West wind with heavy rain at times

.

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend is still towards the milder weather later this week being replaced by something cooler and still unsettled next week with all models now in line in endorsing this pattern.

 

MY THOUGHTS  All models now support the theme of the very mild SW flow giving way to cooler Westerly winds next week. The process will be accompanied by plenty of unsettled and windy weather with some heavy rain at times offsetting the feel of the very mild temperatures in the far SE. Through next week the winds remain strong but with a source nearer to Greenland rather than the Azores temperatures will be forced down to average levels. Low pressure will be deep and dominant for much of the time close to Northern Britain carrying successive bands of rain and showers quickly East across all areas at times. As always in this Westerly regime there will be some drier and brighter days in isolation as transient ridges pass by but there seems little to suggest any major shift back towards High pressure based weather anytime soon with any shift restricted to the final days of the GFS Ensemble group at the close of the run. While winds remain from the West and the profile of the Jet Stream remains as it is predicted to be from next week it is unlikely that the UK will turn particularly cool so frost and fog patches will be restricted as a result. Any troublesome weather likely to be reported upon if anything will be the amount of rainfall that is likely to fall over the period particularly on the Western and Northern up-slopes but elsewhere too are likely to see higher than average rainfall over the period resulting in water tables becoming dangerously close to saturation levels by the end of the period which is not something we want to see this early in the Winter season.

[Summer Sun]

GFS 06z temperature anomaly shows temperatures widely above average across Europe including the UK

 

Temperature anomaly for the next 8 days

 

 

What the 2m temperatures should be

 

 

And the 2m temperatures expected

 

[summer blizzard]

GFS makes us wait until day 10 for a real cool shot.

 

[Frosty.]

Just caught the 6z, it looks like the south will have a lot of fine and very mild weather next week due to increasing influence from the continental anticyclone but not immune from the occasional disturbance with rain pushing east but predominantly fine, it's only really the north of the uk, especially the far north which looks unsettled on most days next week and much cooler than further south but then we have incursions of colder air from the north by the end of next week with a risk of wintry ppn on northern scottish high ground and an increasing frost risk for the uk. it's only at the very end of low res when high pressure builds in but it stays rather cold...so, this weekend looks very mild but breezy / windy and wet at times and in any sunshine in the south, temperatures could reach the low 20's celsius but generally mid to high teens c which is still above average.

Edited October 15, 2014 by Frosty.

[Summer Sun]

GFS 12z similar to the 06z run for the 2m temperatures for the next 8 days with Europe and the UK widely above average

 

Temperature anomaly for the next 8 days

 

 

What the 2m temperatures should be

 

 

And the 2m temperatures expected according to the 12z run

 

[damianslaw]

Unsettled for the foreseeable future, the Jetstream on a crash course for the UK. The mild/very mild conditions set to envelop the country rest of this week, will be tempered down somewhat next week as the jet is forecast to swing more direct across the country, but southern areas will still see temps above average, nearer average in the north with some cooler brighter showery bursts. Plenty of rain also for most, in what is turning into a notably wet month - a far cry from September!

 

As we head into the latter part of the month proper, signs we may see something cooler from the NW, thanks to the position of the Jetstream which seems desperate to keep wanting to track more southerly. It also doesn't look like firing into any real high gear anytime soon neither - something which you be expecting to see at this time of year, and no sign of anything particularly stormy neither. Autumn 2005, 2009 and 2010 were devoid of stormy conditions interestingly..

Edited October 15, 2014 by damianslaw

[sevenkings]

Unsettled for the foreseeable future, the Jetstream on a crash course for the UK. The mild/very mild conditions set to envelop the country rest of this week, will be tempered down somewhat next week as the jet is forecast to swing more direct across the country, but southern areas will still see temps above average, nearer average in the north with some cooler brighter showery bursts. Plenty of rain also for most, in what is turning into a notably wet month - a far cry from September!

 

As we head into the latter part of the month proper, signs we may see something cooler from the NW, thanks to the position of the Jetstream which seems desperate to keep wanting to track more southerly. It also doesn't look like firing into any real high gear anytime soon neither - something which you be expecting to see at this time of year, and no sign of anything particularly stormy neither. Autumn 2005, 2009 and 2010 were devoid of stormy conditions interestingly..

and look what happened in winter 2010. ??  deep freeze,-  2009 and 2005 need refreshing cant remember tbh...

[Polar Maritime]

There are other threads to continue this discussion on Winter trend.

Many Thanks, PM.

Edited October 15, 2014 by Polar Maritime

[ANYWEATHER]

Mild ,cloudy and rather windy and wet for some places for the next few days and over the weekend looks likely the formhorse, Next week , from ecm and gfs shows the winds at times moving from a southwesterly direction to a more westerly even northwesterly direction at times  ushering in some colder conditions. Its the final phases of the ecm and gfs show some proper cold coming into the uk towards the latter end of the month.....

[Polar Maritime]

Yes AnyW.. Cool/Cold N/W'ys still continue to be the firm horse towards the turn of the Month.

Edited October 15, 2014 by Polar Maritime

[knocker]

Tonight's D10 anomalies sounds a bit like a broken record.

 

Trough Greenland stretching to eastern Europe. HP North America with a trough along the eastern seaboard. A ridge mid Atlantic and warmish air Europe. The one difference between the GEFs and ECM is the latter extends the northern trough SW over the UK. Make what you will of a complex meridional jet but I feel it's facilitating the movement of depressions via the gateway of the trough along the seaboard.

 

Oh and is that a split vortex.

 

So same surface analysis. Low pressure dominate in the Atlantic giving periods of wet and generally unsettled weather with about average temps. I think I'll copy and save this for tomorrow.

Edited October 16, 2014 by knocker

[Polar Maritime]

Plenty of Snow over the Alp's months end by the GFS, Jet way South.. Models are really struggling with the High Latitude Blocking, Some big swings. A cool/cold Pm flow still remains last 1/4 of October, Turning N/E maybe.

 

Edited October 15, 2014 by Polar Maritime