Model Output Discussion 1200 hrs 30/09/14

[knocker]

 The monthly ECM mean

Edited October 17, 2014 by knocker

[Gibby]

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY FRIDAY OCTOBER 17TH 2014.

 

NEXT UPDATE SATURDAY OCTOBER 18TH 08:00

 

THE CURRENT GENERAL SITUATION. A deep Low in the mid Atlantic will move very slowly NE with a very mild SSW flow over the UK with occasional troughs moving NE in the flow.

 

MODELS-2 WEEK HEADLINE  Changeable weather with rain at times but some drier and brighter periods across the South at times too. Near or slightly above average temperatures.

 

THE JET STREAM ENSEMBLE FORECAST The Jet flow is shown to blow in a NE direction across the UK for the next few days before turning more West to East over the UK next week. Beyond that the UK remains the home for the flow probably backing towards a SW to NE axis again through part at least of Week 2.

 

GFS The GFS operational today shows the current SW flow veering more Westerly next week before easing across the South later as a strong belt of High pressure lying to the South of the UK becomes more influential with time. Through week 2 the pattern remains changeable with the High pressure across the South extending further North to all areas at times. This means than occasional rain next week will gradually become more restricted to northern areas with time with the dry and fine weather across the South extending to all areas at times with mists and fogs possible at night.

 

THE GFS ENSEMBLES. The GFS Ensembles are less supportive of the High pressure belt to the South giving anything more than occasional drier and brighter spells across the South with the North unsettled, windy and sometimes wet throughout. The South too would see some rain at times along with breezy conditions with temperatures held to values close to or above the seasonal average.

 

UKMO UKMO this morning shows an active cold front sweeping SE on Tuesday with wind and rain for all for a time before cooler and fresher air brings a mix of sunshine and showers, wintry on Scottish hills. Milder weather returns on a blustery Westerly wind through Wednesday and Thursday with some rain at times especially over the North and West.

 

THE FAX CHARTS  The Fax Charts support the raw data in full today gradually lowering temperatures towards the seasonal average early next week and as an active cold front sweeps SE on Tuesday a chilly 24 hours with showers is shown with milder air over the Atlantic poised in the wings to move across the UK around midweek.

 

GEM The GEM operational today suggests a changeable pattern under a basic Westerly flow with bands of rain and showers moving East across the UK at times. Temperatures would be lower than currently but still relatively mild but windy offsetting the feel. Late in the run a cool NW flow heralds the arrival of higher pressure towards the SW of the UK.

 

NAVGEM NAVGEM maintains the rather changeable theme with strong breezes and rain at times though the South would see least as pressure stays High to the South. Temperatures will stay on the mild side of average for many though a few cooler and showery interventions can be expected across the North at times next week. 

 

ECM The ECM operational today continues a blustery feel next week with a mix of bright spells and periods of cloud and rain and showers. Temperatures will fluctuate but be lower than currently but never particularly chilly. The South will see the best of any dry weather and later in the run a strong pressure rise close to the SW would bring dry and fine weather to many areas by Day 10 with the introduction to the risk of mist and fog patches.

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend remains unchanged from the basic Westerly flow continuing across the UK, most active over the North.

 

MY THOUGHTS  The models continue to promote a continuation of SW and then Westerly winds across the UK over the coming two weeks with rain and wind at times. Pressure remains projected to be High to the South of the UK which will serve to reduce the affects of more active fronts crossing the North as we move deeper into next week. Nevertheless the influence of this large High pressure belt to the South could serve to stall fronts coming down from the North to stall over Southern England on occasion giving rise to cloudy and drizzly conditions at times at least. However, later in the period the longer term models have a desire to push this High pressure belt up towards and perhaps into the UK giving rise to drier and brighter weather for all with mist and fog problems developing at night should this occur. Over the period as a whole temperatures will hold up well towards average or above but it is unlikely that the current high vales would be maintained. In fact there could be a few polar maritime interventions of air which could deliver wintry showers over Scotland briefly next week but given the time of year it still looks unlikely that anything wintry be it in a calm anticyclonic way or any other is shown by any output this morning with no real pattern shift shown away from this basic Atlantic driven Westerly pattern on the output today.

[knocker]

Day 10 GFS and ECM anomalies are not totally inconsistent.

 

[Newberryone]

Yes it does look like Temps will turn more Seasonal by Months end Frosty, As Models also indicate.

 

 

Snow lying not a couple of hours drive from Oslo in Norway today, according to this Facebook Nature Watch Group discussion which shows the garden white with snow and birds coping as best they can.

 

My point is this, lying snow is quite unusual at this time of year according to the author of the post and despite a fairly active Atlantic, giving the recent model outputs, there could yet be more to come. As for us, we will be enduring very mild Temps for a few days before a cooler unsettled spell returns. I still have faith in my predictions from a couple of days ago regarding those two late October dates to watch. I'm not suggesting a widespread wintry scene across the UK but I suspect the chances of one affecting at least the far Northern parts are increasing as time ticks by.

Seems the two main op models Ecm and Gfs, with quite reasonable support from the Ens means, have altered the landscape somewhat overnight, with what I dare say to many, underwhelming output. I see nothing to suggest anything other than very limited ( if any) PM incursions for the foreseeable.

If anything, the Azores high looks like it could become quite a dominant player from midweek on, should the latest output verify. Then again, perhaps we need to factor in Hurricane Gonzalo with regards to how the models are currently interpreting surface conditions after midweek.

Either way, it all looks a tad benign with slightly above average temps following a very unsettled weekend and start to next week.    

PS  Seems the lack of posts on here today suggest I may have a point.

[Nick F]

Here's my latest synoptic outlook for the next 14 days, including the potential impact on the UK and Ireland of ex-Hurricane Gonzalo early next week. Longer term, not signs of any colder weather, in fact after a brief cool down on Tuesday, as the flow turns northwesterly, temps returning to above average values after mid-week. Hints of stronger ridging building north last weekend of October as the clocks go back, which could last through last week of October:

 

http://www.netweather.tv/index.cgi?action=news;storyid=6230;sess=

[Frosty.]

The GFS 06z op run is showing a very mild and anticyclonic end to october and early november with a tropical airmass feeding around the top of high pressure to the south, quite balmy conditions for the time of year with unsettled weather becoming restricted to the far western and northern extremities of the uk and even those areas may fine up into nov, very unseasonably mild or you could even call it warm..early movember BBQ anyone   17 / 18 celsius in the south

Edited October 17, 2014 by Frosty.

[shaky]

The GFS 06z op run is showing a very mild and anticyclonic end to october and early november with a tropical airmass feeding around the top of high pressure to the south, quite balmy conditions for the time of year with unsettled weather becoming restricted to the far western and northern extremities of the uk and even those areas may fine up into nov, very unseasonably mild or you could even call it warm..early movember BBQ anyone   17 / 18 celsius in the south

dont be fooled frosty cos I reckon night times could be really cold under the influence of that high!!

[Frosty.]

dont be fooled frosty cos I reckon night times could be really cold under the influence of that high!!

I think there would be a lot of cloud associated with those 6z charts but with sunny spells to the east of high ground and across the SE, little or no chance of frost I would have thought.

.

To be honest I would much rather see an early cold snap than yet another..yawn.. very mild benign spell but we have to accept what the weather gives us, a bit of charity towards coldies would make a pleasant change!

Edited October 17, 2014 by Frosty.

[Captain Shortwave]

In the near reliable timeframe, the GFS has suddenly thrown a nasty looking depression down the north sea.

Never welcome at this time of year. There could be gales along eastern coasts.

[Summer Sun]

In the near reliable timeframe, the GFS has suddenly thrown a nasty looking depression down the north sea.

Never welcome at this time of year. There could be gales along eastern coasts.

 

UKMO for the same time, could get quite windy for a time down the east coast

 

 

GFS settles things down by mid week

 

Edited October 17, 2014 by Summer Sun

[phil nw.]

In the near reliable timeframe, the GFS has suddenly thrown a nasty looking depression down the north sea.

Never welcome at this time of year. There could be gales along eastern coasts.

Yes a vigorous little secondary development Captain.The UK and ECM models actually showed this sort of feature on yesterdays 12's.

A short blast of colder air before it quickly moves away

http://modeles.meteociel.fr/modeles/gfs/runs/2014101712/gfs-1-96.png?12?12

To be replaced by rising pressure and warmer air again.

[Mucka]

Quite large differences between UKMO and GFS re how they handle the Scandi ridge and distribution of energy that comes up against it.

It is a known failing of GFS that it has a bias to want to send energy "over the top" rather than undercut in these situations/

 

GFS/UKMO comparison NH day 7

 

[phil nw.]

Anyone notice the vortex shape on the UK 120hrs?

I did think it was calling for help,

link

http://www.meteociel.fr/ukmo/runs/2014101712/UN120-21.GIF?17-18

(sorry haven't worked out how to post images on this tablet yet)

Certainly not a vortex able to consolidate itself properly yet.

[gottolovethisweather]

Seems the two main op models Ecm and Gfs, with quite reasonable support from the Ens means, have altered the landscape somewhat overnight, with what I dare say to many, underwhelming output. I see nothing to suggest anything other than very limited ( if any) PM incursions for the foreseeable.

If anything, the Azores high looks like it could become quite a dominant player from midweek on, should the latest output verify. Then again, perhaps we need to factor in Hurricane Gonzalo with regards to how the models are currently interpreting surface conditions after midweek.

Either way, it all looks a tad benign with slightly above average temps following a very unsettled weekend and start to next week.    

PS  Seems the lack of posts on here today suggest I may have a point.

 

Yes Newberryone, I had previously highlighted my concerns as to how the influence of the High pressure incursions might end up changing things. For instance here in the last three sentences I pondered the chances of things staying as I hoped re: the NW'rly. I still suggest the brief Northwesterly interlude will come to fruition but as you indicate its unlikely to be anything of much concern for folk further South. I generally ignore the overnight runs and look for patterns in the Afternoon and Evening model suites over time. Certainly we're now entering a timescale where many a FI tease will show up in the outputs and its simply whether these recur enough on a daily basis to constitute an underlying trend. Plenty of things to watch for sure.

Edited October 17, 2014 by gottolovethisweather

[Bobby]

Yes a vigorous little secondary development Captain.The UK and ECM models actually showed this sort of feature on yesterdays 12's.

A short blast of colder air before it quickly moves away

http://modeles.meteociel.fr/modeles/gfs/runs/2014101712/gfs-1-96.png?12?12

To be replaced by rising pressure and warmer air again.

 

The remains of Hurricane Gonzalo.

 

 

Looks windy

 

Edited October 17, 2014 by Bobby

[carinthian]

Well just one run from the 12z GFS and it opens up a snowfest  for the Austrian Alps for first day of November and a possible easterly heading for the UK. As I say just one run, but better than a warm Euro High 1

 C

[Polar Maritime]

Well just one run from the 12z GFS and it opens up a snowfest for the Austrian Alps for first day of November and a possible easterly heading for the UK. As I say just one run, but better than a warm Euro High 1

C

Yes C they hinted this of sorts the other day as i mentioned, The Models are really skitty atm out in the runs as they continue with difficulties with the strong heights over the Northern Hemisphere. Edited October 17, 2014 by Polar Maritime

[knocker]

The China model has slightly different time frame for Gonzalo lagging the GFS

Edited October 17, 2014 by knocker

[Nick L]

ECM monthly showing more colder options towards the end of the period at first glance, will elaborate further when I get the chance.

[Summer Sun]

Tuesday is looking wet, windy and cold with the east taking the brunt of the strong winds

 

 

By Wednesday that all pushes east allowing some warmer air to move back in from the west

 

 

By next weekend some rain and cloud is still possible at times especially the further north you are

 

 

By day 9 and 10 high pressure is sat over us, warmer for all by day but nights could be colder with some fog

 

[Captain Shortwave]

The week 2 charts from the ECM look dubious to say the least. That building of pressure over the UK looks very overdone.

To be blunt, at day 9 that 1030mb UK high has appeared literally out of thin air. Not much chance of that given the day 8 chart, modest heights over the south at best. Still the  ridge on the Pacific side looks decent enough.

Edited October 17, 2014 by Captain shortwave

[nick sussex]

Interesting ECM T240hrs chart with the troughing amplifying over the eastern USA and a cross polar flow with the PV in Siberia:

 

 

I'd say its the most interesting output we've seen so far this autumn but of course at ten days out a lot could change, something to keep an eye on in the coming days.

 

 

 

 

 

 

[shaky]

The week 2 charts from the ECM look dubious to say the least. That building of pressure over the UK looks very overdone.

what a split vortex and northern blocking at the end of the ecm run though!!!the vortex is very weak and virtually non existent so far!!!confidence is gathering for a negative opi overall in my opinion!!

[Purga]

A promise of things to come over the winter we hope?

 

[bluearmy]

Interesting ECM T240hrs chart with the troughing amplifying over the eastern USA and a cross polar flow with the PV in Siberia:

 

ECH1-240.gif

 

I'd say its the most interesting output we've seen so far this autumn but of course at ten days out a lot could change, something to keep an eye on in the coming days.

 

the modelling of the arctic on the ops is rather inconsistent in week 2.  what is fairly consistent is the lack of appetite to build a compact p/v and the amplified nature of the runs would possibly lead to feedback loops of amplification via wave breaking from the trop into the strat.