Model Output Discussion 1200 hrs 30/09/14

[knocker]

The GEFS anomaly chart has a respite from the current Atlantic domination the middle of next week with a ridge to the SW of the UK. Still above average temps. Alas, it is just a passing phase with a quick return to the natural order of things.

Edited October 16, 2014 by knocker

[Captain Shortwave]

Nothing particularly drastic in the output really. Looks like a standard changeable westerly pattern with rain at times along with some drier and brighter spells. Temperatures look  little above normal on the whole with even PM shots limited in nature.

Whilst the ensembles do tend to drain heights away, there is nothing particularly organised about the tropospheric vortex even out to the end of the month. I suspect the OPI will stay negative enough to give hope of a better winter.

 

Worth noting the volatility in the ops though

GFS

 

GEM

[Nick L]

ECM deciding to put out a very brief northerly at +144 bringing some sub-zero 850s, before the ridge supporting it collapses away somewhat.

[Gibby]

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY THURSDAY OCTOBER 16TH 2014.

 

NEXT UPDATE FRIDAY OCTOBER 17TH 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 will blow in a NE direction over the UK for the remainder of this week. Thereafter it tilts more West to East across the UK as it ridges over the Atlantic. This ridging amplifies further later in the run with the UK lying in the South moving feed on the Eastern periphery of this flow late in the run.

 

GFS The GFS operational today shows Westerly winds dominating the weather across the UK for the entire period this morning. The Westerly flow will be a cyclonic one for the most part with deep Low pressure moving East to the North carrying troughs across the UK at times with rain and showers. High pressure will not be far to the South at times and this allows less rainfall in the South and East with longer dry spells and temperatures never far from average if not above at times in the South.

 

THE GFS ENSEMBLES. The GFS Ensembles support the Westerly theme through it's run too but shows slightly lower pressure overall with some heavy rainfall reaching the South at times too and a shift to much cooler and showery weather in a Northerly to end the run with the risk of wintry showers for a time in the North and an increase in the possibility of the incidence of frost and fog

.

UKMO UKMO this morning shows a strong Westerly flow across the UK early next week with a trough moving across on Tuesday carrying a band of rain followed by fresh WNW winds and some showers across the North and West in particular.

 

THE FAX CHARTS  The Fax Charts shows the mild SW flow turning more Westerly with time and taking away the cold front edging across the SE at the weekend and the mildest air ahead of it. A fresher westerly flow is then shown with further Atlantic troughs queued up to cross the UK early next week.

 

GEM The GEM operational today shows unstable Westerly winds throughout next week with temperatures nearer to average than currently. There will continue to be rain at times as troughs cross East on occasions in the strong West flow.

 

NAVGEM NAVGEM indicates a less strong Westerly flow with higher pressure especially over the South. Nevertheless, there will continue to be rain at times for all but most of the heaviest rain towards the NW with longer drier spells in the SE with temperatures near or a little above average in general. 

 

ECM The ECM operational today leans towards rather better weather across the South developing with time as a spell of rain early in the week from a trough clears SE allowing pressure to rise close to the South. This then holds as a ridge later with the Westerly flow shown by other output restricted more towards Northern Britain where rain and showers continue while the South turn dry and bright with mist and fog issues possible night and morning.

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend has been for pressure to rise close to Southern Britain next week although it's only ECM which shows this as a major influence to the weather in the South.

 

MY THOUGHTS  The pattern across the UK over the next few weeks continues to look very Atlantic dominated. However, things between the models are not that straightforward and one of the notable themes I have picked up on in the past 24 hours is the desire to track the Jet Flow slightly further North than recent output sufficient to allow pressure to rise across France and Biscay. This steers Low pressure slightly further North and lessens the effects of these somewhat across the South. However, at the moment most output shows changes from recent output only limited with all areas subject to wind and rain at times next week with the more likely effects being the lessening in both the strength of the wind in the South as well as less rainfall in general down here. However, ECM goes one step further and brings a strong High close to Southern Britain by midweek next week which then holds as a ridge close by thereafter and would bring dry and quiet weather down here while the unsettled conditions continue further North. So all in all it's still a breezy and changeable period to come for all areas but there is room for some better weather to develop across the South at times over the next few weeks and it looks a good deal less wet than some output was showing yesterday morning with temperatures continuing to be shown to hold up reasonably well everywhere over the period.

[Frosty.]

The Gfs 00z op run shows very mild / rather warm airflow from the Azores swamping the whole uk, especially during this weekend with temperatures well into the mid teens c but nearer high teens celsius across the south / se, perhaps touching a very warm 22-23 c in the southeast in any decent sunny spells with 564 dam just clipping the SE corner during saturday but it also looks unsettled with bands of rain crossing from west to east, quite windy too but sunday looks the drier, sunnier day across the south & east although temps slightly down on saturday, it's worth mentioning that saturday night could be incredibly warm for the time of year with temperatures no lower than 17 / 18c in the south but then turning somewhat cooler and fresher next week across the north, closer to the seasonal average with an undulating but broadly westerly flow, coolest, breeziest and most unsettled up north, fine at times in the south where pressure will be higher and it will still be on the mild side of average with tropical maritime airmass but not to the same extent as the next few days and by the end of next week into the following week, this run shows a chilly flow from north of west for a few days with temperatures slipping below average.

[Nick L]

Yes the overall picture really hasn't changed a great deal. Wet and mild for the foreseeable unfortunately. Some minimum temperature records could be at risk over the weekend.

 

ECM monthly is updated tonight so hopefully we'll get a glimmer of change at least from that!

Edited October 16, 2014 by Nick L

[Summer Sun]

GFS 00z anomaly's continue to show above average 2m temperatures widely across Europe and the UK for the next 8 days

 

8 Day anomaly

 

 

Normal 2m temps

 

 

Expected 2m temps

 

[knocker]

If the ECM/GFS 8-10 day mean chart is to be trusted this morning, it looks like we could get some decent weather for the south with reasonable temperatures, not so settled and cooler up north:

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

 

Problem there is pjl is if one looks at the actual for D10 you get a slightly different picture. As I've mentioned before it rather depends on the precise latitudinal orientation of the cold and warm air. Mind looking slightly further ahead a different picture is painted.

[Frosty.]

Yes Gav (summer sun) but beyond day 8 it looks colder than we have encountered this autumn so far with a higher risk of frost and even a chance of wintry ppn across northern high ground at times.

[summer blizzard]

GFS does cool down from day 8 but only to near average with the jet for all intensive purposes straddling the UK.

 

[johnholmes]

If the ECM/GFS 8-10 day mean chart is to be trusted this morning, it looks like we could get some decent weather for the south with reasonable temperatures, not so settled and cooler up north:

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

I am a bit unsure as to how you make that statement. Okay let's take just the one output. The EC version does indeed show +ve anomalies into southern UK but of more impact I would suggest is the contour pattern. This shows a broad fairly westerly flow and quite strong suggesting a rather unsettled type of weather pattern. Maybe less so for the SE quarter. It is just one output from one model and if you look at the GFS version it shows even less suggestion of any really settled weather.

The EC version fits more closely with the trend over the past few days on all 3 main anomaly charts and often the NOAA turns out nearer to the actual pattern when there are differences. This has kept the idea of a strongish westerly flow originating from the northern end of the Gt Lakes which would suggest again unsettled for most and not especially feeling warm/mild particularly in wind and rain.

[phil nw.]

The Atlantic pattern is certainly looking typically Autumnal now with the Jet aiming across our latitude over the next few days.

A look at the NH flow from the latest 06zGFS run shows it digging well into mainland Europe.The second image shows the boundary layers between the air masses north and south of it and why the projection of a warm up over Western Europe shows in the charts Gavin(SS)posted above. 

 

 

the milder air looking likely to be over the UK until around the middle of next week but cloud and rain or showers never far away.

The latest Fax for T84hrs showing plenty of frontal systems around to ensure the changeable theme continues.

 

Later next week there are signs of a return to cooler weather moving across from the west in a brisk westerly flow with bands of rain or showers the outlook into week 2.

This does look like an ongoing pattern towards month end with the heights to our north trending lower and the jet continuing to flow across mid-latitudes for the foreseeable.

 

[Frosty.]

The GFS 06z op run brings another very mild spell in around 10 days time as tropical air feeds around the top of high pressure to the south. In the meantime we have a very mild weekend coming up but unsettled with rain and strong winds in the forecast but the sun will break through in places, especially across the SE and where that occurs, temperatures could soar into the low 20's celsius. Next week also looks unsettled, especially further north and pretty mild again but not as mild as the weekend but relatively colder air pushing southeast by the end of next week for a time with winds veering north of west.

Edited October 16, 2014 by Frosty.

[Nick L]

GFS 12Z making much more of the remnants of Gonzalo next week, certainly worth keeping an eye on.

[Mucka]

Quite a nice ridge building up through Scandinavia into the pole which could be good if you want a negative OPI and it is helping bring the Euro Asian snow cover even further West than the 06z (If you like that sort of thing)

 

 

UKMO provides some undercut to the ridge.

Edited October 16, 2014 by Mucka

[Frosty.]

We are entering that time of year when wintry charts start to appear and today's GFS 12z op run is a perfect example of this with the uk coming close to something wintry from a Northerly and an Easterly, wintry by late october standards. I would love to see snow before november as this would be a huge turnaround from a generally warm autumn so far, the snow would fly if the pattern was shunted at least 500 miles further west as the uk would then be blasted by that strong arctic plunge screaming south through scandinavia..we coldies finally got some eye candy at least.  

[A.J]

We are entering that time of year when wintry charts start to appear and today's GFS 12z op run is a perfect example of this with the uk coming close to something wintry from a Northerly and an Easterly, wintry by late october standards. I would love to see snow before november as this would be a huge turnaround from a generally warm autumn so far, the snow would fly if the pattern was shunted at least 500 miles further west as the uk would then be blasted by that strong arctic plunge screaming south through scandinavia..we coldies finally got some eye candy at least.  

thing is though Karl, those charts just show an autumnal HP in situ, with fog at night and probably some grey murky drizzly weather coming onshore for eastern districts to be fair......even in the Scottish mountains, the freezing level is way up over 3000ft...............but as you say, it will be nice to see more favourable synoptic cpatterns as we move into november, although as Nick L posted yesterday, the ECM monthly didn't paint a pretty picture for coldies, interesting to see if any changes are apparent when the ECM monthly updates tonight 

[Frosty.]

thing is though Karl, those charts just show an autumnal HP in situ, with fog at night and probably some grey murky drizzly weather coming onshore for eastern districts to be fair......even in the Scottish mountains, the freezing level is way up over 3000ft...............but as you say, it will be nice to see more favourable synoptic cpatterns as we move into november, although as Nick L posted yesterday, the ECM monthly didn't paint a pretty picture for coldies, interesting to see if any changes are apparent when the ECM monthly updates tonight  [/

quote]

Hi AJ

Yes that's why I said the UK comes close to something wintry and at least the gfs shows potential which keeps my fellow coldies interested, we have had nothing so far but it whets the appetite for the winter ahead..in my opinion..more eye candy please. :-)

[phil nw.]

At T120hrs ECM and UKMO show a brief swipe of colder air for the far NE 

 

as that low cuts se off the main vortex towards Scandinavia.

 

I can see what Karl is getting at with that 0C 850hPa line easing closer to the UK at times but as AJ suggests it's really just our normal Autumn type of pattern.

Those lower heights to our north and the westerly pattern means any real cold for now remains out of reach with just brief polar maritime incursions for the UK.

 

Let's give it time after all it's only mid-Autumn and the Arctic cold is still building -early days to expect anything of note yet.

[Paul]

Latest from Michael Fish - today being the anniversary of the great storm of 1987, there had to be a mention of an ex-hurricane in the forecast!

 

 

http://www.netweather.tv/index.cgi?action=news;storyid=6228;sess=

[Captain Shortwave]

Though there is a lot of variability over the pole, the end result is pretty similar throughout with a westerly pattern dominating. The tropospheric vortex still looks like it will be taking a beating which is still a good sign overall.

[Frosty.]

Noticed the MO update mentions snow for northern hills next week with cold and strong westerly winds..have a feeling we could get colder showery spells between bouts of wet and windy weather during the weeks ahead.

Roll on winter

[Polar Maritime]

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

Edited October 16, 2014 by Polar Maritime

[gottolovethisweather]

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.

Edited October 16, 2014 by gottolovethisweather

[knocker]

Apologies but rather misleading on reflection. Meant to post the following.

Edited October 17, 2014 by knocker