Model Output Discussion 18z 30/09/15

[mb018538]

GFS 6z shows the block holding firm - though as others have said hints at something a bit more mobile by day 10. In the meanwhile, the first week of November looks exceptionally mild. The lack of storm activity through autumn this year is most unusual!

[Summer Sun]

GFS shows some a deep low coming our way, but not until day 10 after a calm spell this would liven things up a bit with gales cooler air and maybe even some snow for high ground in Scotland

 

[Polar Maritime]

Yes some very mobile weather shown by the GFS again this evening for around the 12th, With severe Gales for the North dragging in some cold uppers from the N/W. With even some wintriness showing over the high spine of the UK. 

Edited October 30, 2015 by Polar Maritime

[Frosty.]

I think it's great to see charts like these from the Gfs 12z as we go further into november, a blast of cold zonality will make a nice change!  

Edited October 30, 2015 by Frosty.

[knocker]

This evening's ecm nips a little weak low north mid week and then returns to a mild south westerly flow before finishing on a high, so to speak.

http://www.tropicaltidbits.com/

Edited October 30, 2015 by knocker

[Summer Sun]

Looking at d9 and 10 from ECM that high ain't in any hurry to leave UK infact the south and SE could see very little if any rain over the next 10 days with the high never far away

 

[knocker]

Tonight's GEFS 6-10 still hanging on to positive heights to the east and trough mid Atlantic poised so tending towards a NW/SE LP/HP split over the UK. As indicated elsewhere the 11-15 dissolves the HP to the east and has the trough to the NW creating a zonal flow bringing more unsettled weather and around average temps. It has to be said NOAA is not yet signed up to the zonality in this time frame.

http://www.tropicaltidbits.com/

 

[knocker]

Although the ext ecm does gradually lose the ridging to the east it still hangs on to HP SW-SE thus not full zonality but the flow more from the SW and temps remaining a tad above average.

[bluearmy]

Still waiting to see a convincing argument that blocking is departing nw Europe . whether it's sceuro or UK, blocking seems likely to remain the story to mid November. let's be honest, the ops have been trying to remove it for a fortnight now but no sign that it's going away. In fact, beginning to see trough disruption mid Atlantic and height rising ahead of the Atlantic trough with split jet being the operational story in week 2. Are the ops finally getting to grips with the background pattern?

[knocker]

Although this morning's ops run is quite fluid vis the upper trough mid Atlantic and the HP adjacent to the UK to the SW and east the status quo doesn't substantially alter. Systems do occasionally nudge in from the west, more particularly in the north but the HP rebuilds. These two charts are just an illustration of this being a week apart.

Charts weatherbell

 

[knocker]

The ecm still toying with the idea of bringing a weak low north midweek before settling down the usual battle between the trough and the HP that results in a general SW air stream. Quite warm.

http://www.tropicaltidbits.com/

 

 

[Radiating Dendrite]

Well the 0z GFS is hardly inspiring. The first chart and the last one in FI look very similar.

 

Think this November could be memorable for being mild and quite settled overall as that euro high looks like it does not want to shift anywhere.

[Frosty.]

Those who think november is going to be a mild benign bore fest should take a look at these GEFS 00z perturbations, there are some very interesting ones, especially around the mid november period with cold easterlies, cold northerlies and a generally more unsettled and windier pattern emerging so I am hopeful we will see a marked change by the second half of Nov, perhaps before !  

[Nouska]

Nice to be back to sunshine after a grey and drizzly end to mid term in Surrey.

 

Looking at the month ahead, in relationship to the two strongest El Ninos in the modern record, modelled temps closer to '82 than '97 - could this be one of these buck the trend, record breaking months. Indications of the warmer segments of both months in the current charts but we know some recent months have been deceiving in end of month prognosis with output altering radically as new month began.

 

This should have a warmer start than '82 ....   

 

The two months in full....

 

http://www.meteociel.fr/modeles/archives/archives.php?day=1&month=11&hour=0&year=1997&map=0&mode=2

 

http://www.meteociel.fr/modeles/archives/archives.php?day=1&month=11&hour=0&year=1982&map=0&mode=2

 

The top NOAA analogue (1994) has a whopping 10.1C as the November CET....    http://i.imgur.com/qWiuJ3C.gif

 

  ....will be interesting to see how it plays out as the month unfolds.

[johnholmes]

It will be interesting to watch which model consistently and correctly predicts a change in pattern from the current set up. Will it be the anomaly charts or the synoptic models? That is within a 15 day time scale as the anomaly charts only go out that far.

[Ali1977]

Frosty is right, GFS Ens are the best so for with regards potential cold..FI but you never know.

[cold snap]

Fresh start to the thread please mods

[Polar Maritime]

Fresh start to the thread please mods

We will start a fresh thread for November later this evening.

[IDO]

The JMA keeps the block to our east as a strong anomaly for week 1 and 2, and even in week 3-4 the anomalies go with the four wave NH profile:

 

Week 2:   Week 3-4: 

 

So even by the last third of November a relatively settled outlook for the E/SE with T850's above normal. The ebb and flow of the trough and block means that as the UK is on the edge of this battle there could be the odd LP incursion.

 

Fairly good agreement amongst the medium range models as the CFS agrees with the JMA for week 3 and 4:  

 

The Met latest long range (month) also agrees: http://www.metoffice.gov.uk/public/weather/long-range-forecast

 

Still not seeing the MJO as instructive of output, as it is predicted to move through the phases: 

 

So the theme of the Autumn remains, good blocking, although the HLB is replaced by the 4 wave MLB'ing. Until we see this consistently shown as being moderated, the best bet will be the status quo for possibly most of November. No sign of any incursion of cold, though nights may be chilly under clear skies.

[Singularity]

The messy state of the polar vortex on most of the det. model runs continues to stand out to me. It's no wonder the wavenumber looks to be down to 4, though this is more of a Central Pacific El Nino type arrangement than East Pacific. So it is that we see particularly large troughs reaching unusually far south, and strong ridges extending a long way north. Without much forcing to change the arrangement from one with a mid-Atlantic trough and Eurasian ridge, we do have the potential for the warmest first half of November on record, or at least close to it.

 

The 00z GEFS do cast a shadow of doubt on that, but they may be being too aggressive with the Atlantic jet - achieving rearrangements when really the block would hold its own.

[phil nw.]

The overall pattern of Euro high and Atlantic troughing looks set to continue well into November.

Some ebbing and flowing between the 2 main features during the coming days which will see some surface changes across the UK though.

A look at 2 of the fax's from the overnight run

 

 

The first image shows the ridge reasserting itself which is now bringing dry and quiet weather with some brighter spells but also the risk of mist and fog night and morning in some areas over the next couple of days.

The second image indicating low pressure and some rain moving north east around midweek but all the time temperatures remain mainly well above normal because of the mild and damp tropical maritime flow from the south west.

Loking ahead into the week after- no real change with the ens means

 

any mobility off the Atlantic still looking muted with any unsettled weather that tries to get in having to continually fight against the persistent blocking nearby.

 

 

 

[shuggee]

A tad blowy at T+384.

 

 

As usual GFS blows away the euro/scandi high when into low-res.

[Frosty.]

The Gfs 6z op run shows an increasingly fired up atlantic taking on the strong Euro Block and towards the end of the run the uk becomes very unsettled with gales / severe gales and colder incursions bringing wintry ppn to northern hills / mountains. In the short term, the Euro High is dominant with fine weather across most of the uk, exceptionally mild in the sunny spells but where fog forms overnight, it could linger and in those areas it would feel rather chilly, tonight for example looks very foggy across much of england and wales. Looking further ahead, it's later next week when this run shows our weather becoming less settled but it's the more northwestern parts of the uk which bear the brunt of the atlantic systems sweeping NE past NW Scotland but eventually we all see a big change. Those of us who don't want november to be one long mild benign bore fest will like this run...and that includes me.

[mulzy]

The Gfs 6z op run shows an increasingly fired up atlantic taking on the strong Euro Block and towards the end of the run the uk becomes very unsettled with gales / severe gales and colder incursions bringing wintry ppn to northern hills / mountains. In the short term, the Euro High is dominant with fine weather across most of the uk, exceptionally mild in the sunny spells but where fog forms overnight, it could linger and in those areas it would feel rather chilly, tonight for example looks very foggy across much of england and wales. Looking further ahead, it's later next week when this run shows our weather becoming less settled but it's the more northwestern parts of the uk which bear the brunt of the atlantic systems sweeping NE past NW Scotland but eventually we all see a big change. Those of us who don't want november to be one long mild benign bore fest will like this run...and that includes me.

 

 

"Those of us who don't want november to be one long mild benign bore fest will like this run"

 

If the November weather is like today, long may the "borefest" continue.  If we can't get blizzards then let's have what we currently have rather than the usual wet and windy.

Edited October 31, 2015 by mulzy

[Evening thunder]

"Those of us who don't want november to be one long mild benign bore fest will like this run"

 

If the November weather is like today, long may the "borefest" continue.  If we can't get blizzards then let's have what we currently have rather than the usual wet and windy.

 

Well if it was sunny most of the time at least. Unfortunately this pattern is often likely to be cloudy/murky and dull for many, with maybe some fronts entrained giving light-moderate rain and drizzle (as the GFS illustrates for the coming week and beyond). Even in sunny breaks it will often be hazy with limited visibilities from viewpoints.

 

I'd definitely take a properly mobile Atlantic over a Eurohigh all month, especially after October's lack of weather.. it would probably provide more sunshine too (as well as very good visibilities compared to hazy stagnant polluted air).