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Thunderbolt_

Model Output Discussion - 18z 31/10/15 onwards

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Hi everyone, this is my first time starting a model thread. :)

 

As we move into November, we are seeing quite a prolonged and warm spell of anticyclonic weather. However with the possibility of threatening the all-time November high tomorrow, will the models start hinting at the possibility of a breakdown to more Atlantic-driven weather soon? Furthermore, could we even see the first proper cold snap of the autumn/winter season this month?

 

Continue the discussion. :)

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Nothing major to speak of, albeit a shift towards the Atlantic looks like a possibility after a few days of relatively settled weather. One thing I've noticed in the trends - silly to look for anything more than that at this point - is the notable downward trend in 850s. See this for leeds from the 18Z GEFs Ens:

http://modeles.meteociel.fr/modeles/gens/graphe_ens3.php?x=267&ext=1&y=13&run=12&runpara=0

Quite a few of the postage stamps show HLBs by the end of Lala land so just something worth pinning in the background - if only to remind us that with November starting as of 30 minutes ago, wintry Synoptics need never be too far away...

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Nothing for coldies once again this morning. Looking at the small picture, all models show repetitive bursts of mild air across the UK, with fronts brushing the west and only occasionally getting through to the east. Big picture, a zonal train is getting set-up, supported by a PV lacking in any significant holes for pressure to rise into. The only difference from a typical zonal pattern is that it is keeping rather more to the north of us than usual, which allows the UK to remain near storm free, at least or until D10 - after that, the GFS leaves the question more open.

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Whilst nothing seems particularly definitive this morning, the individual gefs have been offering fairly amplified solutions in reasonable numbers over the past few days. The 00z output has a fair number of Greenland/East Canadian blocking members on the table in two weeks.

I am increasingly of the opinion that we could end up quite frustrated come December as we see decent blocking in that region leading to a west based -NAO delivering the cold air to the mid Atlantic rather than nw Europe. Of course, that building block at least provides for us to end up the right side for coldies should the pattern be further east.

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The GEFS anomalies this morning are not unfamiliar. The 6-10 has the ridging to the east, deep trough mid Atlantic resulting in warm south west stream lines. The 11-15 flattens the flow but weakens the trough and importantly retains the HP orientated more east west and still influencing most of the UK. How far north this influence extends is the key but so far so good with most of the movement of the Atlantic systems being tracked to the N.

 

Does this morning's ops run reflect this. Pretty much. Although there is a fair bit of mobility as the warm and colder air jockey for position with occasional ingress of the former, generally speaking the warmer air wins out as can be seen by the charts at the end of the run which illustrate this quite well. And just to reiterate these charts are not being used as a forecast.

Charts weatherbell and http://www.tropicaltidbits.com/

 

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In the shorter time frame the ecm still has the shallow low Brest by midweek before reverting to a nice southerly flow and some quite warm temps. The dafs certainly think it's xmas already.

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You do not need a Hubble telescope to find cold potential. However we must look towards Mid November the morning GFS shows what we need to look, for the pesky euro high to dissipate and loosen east with southerly tracking lows indicative of a southerly tracking jet. Also note virtually all the chunks/lobes of PV are on Eurasia side on other side it is actually more susceptible to a block be that a Mid Atlantic block or Greenland high of some form - we are very fortunate how this euro high will eventually relent not diminishing our winter cold chances. I think there are reasons for Coldies to be overall quite cheery, expect more eye-candy in the coming days and weeks. I think we could be on course for a cold start to winter, contrary to what others are saying.

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Lots to be positive about, GFS starting to look better mid Nov , Siberian snow cover is good, Midoki El Niño forming, Tripole ish Atlantic, and the last time it was this warm in Nov was 1946

I have a feeling late Nov nov may be a shock to the system.

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You do not need a Hubble telescope to find cold potential. However we must look towards Mid November the morning GFS shows what we need to look, for the pesky euro high to dissipate and loosen east with southerly tracking lows indicative of a southerly tracking jet. Also note virtually all the chunks/lobes of PV are on Eurasia side on other side it is actually more susceptible to a block be that a Mid Atlantic block or Greenland high of some form - we are very fortunate how this euro high will eventually relent not diminishing our winter cold chances. I think there are reasons for Coldies to be overall quite cheery, expect more eye-candy in the coming days and weeks. I think we could be on course for a cold start to winter, contrary to what others are saying.

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Very basic question from an amateur soor but where do you get the charts in the post above from? Ive tried numerous times on the meteociel website but cant find them!

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It's been difficult to drag myself out of summer hibernation this year, the 4 wave resulting in a Euro High pattern is the stuff of nightmares as most of us here I'm sure know how difficult it can be to shift. But hey, it's November, not January, so no worries on the time front at least!

The first half of November therefore looks highly unlikely to produce our first proper cold spell of the season, I think the Atlantic breaking through and a spell of wet and stormy weather would be the favoured option ahead of any cold spell anyway. Which, let's face it, probably holds true for a good 9 out of 10 Novembers!

That said, there have been a few subtle hints out in far FI of the past few GFS runs that a more favourable (in terms of cold) pattern change may be on the cards for Mid month. Ensembles will come into their own here, as will the anomaly charts, on picking up a potential change.

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Very basic question from an amateur soor but where do you get the charts in the post above from? Ive tried numerous times on the meteociel website but cant find them!

Check your inbox - moderators please delete both of our posts.

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Very basic question from an amateur soor but where do you get the charts in the post above from? Ive tried numerous times on the meteociel website but cant find them!

 

On the maps just click the Map Hemi. North tab and it will get the charts

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The November temperature record went today looking at GFS it could be challenged again next weekend

 

ukmaxtemp.pngukmaxtemp.pngukmaxtemp.png

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After todays record breaking day (In Wales at least), temperatures will dip somewhat down to just above average as the 850s mix out over the UK, we also will see some showery rain pushing north during the middle of the week as a cut off low moves north and re-engages with the jetstream pushing across the north of the UK. Shown nicely by the UKMO.

UW72-21.GIF?01-17

After this a more typical NW/SE split develops as heights re-establish over Europe with low pressure running just north west of the UK with rain for the north west but very little getting to the south and east of the UK.

Despite being in November, there is enough evidence to suggest that the 20C barrier could again be breached given the current output (possible tomorrow in the west again, but also next Saturday going by these charts).

gfs-0-144.png?12

UW144-21.GIF?01-17

 

It would be all down to the strength and direction of the wind, but this warm sector is again bringing some very high 850s for the time of year (8-12C). The GFS showing some impressive maxima for next weekend.

150-582UK.GIF?01-12

19C widely across the central/southern England with 20/21C possible.

A long way off but there isn't much really to talk about otherwise from a broad SW flow set up which appears to be gaining momentum at the present time.

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Nothing for coldies once again this morning.

I feel it's a bit early for cold chasing. I'm giving it another 3 weeks / a month at least.

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Another heating bill slasher from ECM tonight. An almost persistent SW -SSWly setting up after mid week, with the 10C 850 line a frequent visitor, and just the right spot to keep the winds up and hence the fog away. Expect several more days in the mid to high-teens before mid-month if this run is close to the month. A further week of this pattern after D10, and the November CET could be the next record under threat

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The GEFS 6-10 is much as it has been for some days so much of the UK remaining under the influence of the surface HP with south westerly streamlines. The 11-15 continues to flatten the pattern and veering the upper flow albeit still maintaining HP influence over certainly the southern half of the UK which the detail will resolve. Looking at the latter end of the ops where there is a development of an upper trough to the east whether this may a way forward from here and a gradual retrogression of the HP currently to the SE.

http://www.tropicaltidbits.com/

 

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I feel it's a bit early for cold chasing. I'm giving it another 3 weeks / a month at least.

 

Yes too early yet, I'm still looking for fine weather on models, Ilike the ECM 12Z for my location, mild/warm and not much rain, it can stay mild until say 25th Nov or so

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With the high dominating over mainland Europe and extending across to the UK the south and south east will see very little rain for the foreseeable future there are some exceptions though the far north and west will have some rain at times as low pressure systems track towards Iceland it will also be breezy at times but it will be a warm / mild one coming from the south west

 

Recm1201.gifRecm1681.gifRecm1921.gifRecm2401.gif

 

Until the high over Europe breaks down the pattern we're in won't be changing much anytime soon

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Well, following the warmest / hottest November day on record according to BBC weather, 22 celsius in parts of wales, I'm willing those lovely blue colours on the T850 charts to reach the uk around mid november time or at least during the 2nd half of Nov  :cold: , the Gfs 12z op run shows a change from the current quiet benign weather in the short term to generally very unsettled conditions through low res with very windy / stormy conditions at times and pushes colder air close to the uk towards the end of the run, surely if we keep seeing charts like these, the right combination to draw cold air across the uk will be found with Arctic air not too far away to the NW.. i'm not waiting another month to start chasing cold, let the games begin already! :D

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With the high dominating over mainland Europe and extending across to the UK the south and south east will see very little rain for the foreseeable future there are some exceptions though the far north and west will have some rain at times as low pressure systems track towards Iceland it will also be breezy at times but it will be a warm / mild one coming from the south west

 

 

 

Until the high over Europe breaks down the pattern we're in won't be changing much anytime soon

 

Past history tells us that Euro highs are the biggest limpets around. Could well last right through November.

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Signs from the ens. that the euro heights will flatten in week 2 and we lose the ridging towards Scandianavia.

This will see the jet easing further south with some polar maritime air getting into parts of Scotland at times.

The difference in the pattern in 24hrs and by day 8 from the GFS ens.mean shows how the pattern is expected to evolve.

post-2026-0-44951600-1446407682_thumb.pnpost-2026-0-03589400-1446407694_thumb.pn

 

We can see how the block changes it's orientation later on.

Although the flow will still be from between south and west some colder air from the north Atlantic will start to become available behind any cold fronts towards the north west quadrant of the UK.

While the mild theme continues further south it will start to feel more seasonal(colder) up north with quite a wide range of max temps.

So yes the mild theme continues for another week or so but just the first signs of the jet becoming more active and easing south bringing that polar air closer to the far north.

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Theres limpet highs and then super limpet highs. The Euro falls into the latter with a painfully slow process to flatten it, the ECM which hinted it might remove it a few days back has gone off the idea whilst the GFS seems a bit more bullish.

 

I'd be wary of any change until this shows up within T240hrs consistently and ticks down rather than what we've seen with a hint at T240hrs which seems to stay there for days.

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Air from near the Azores gets thrown our way around the Euro Ridge according to the majority of recent GFS det. runs.

 

The 12z delivers 20*C in East Anglia next Saturday which is just bonkers. The 2m temp anomalies look like this:

 

gfs_T2ma_eu_25.png

 

Is the Nov CET heading for a record first half? Seems likely to me.

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The ext ecm shows no definitive signal for losing the ridging to the E/SE by T360 thus keeping the UK in a W/SW air stream and still under the influence of the surface HP. The NOAA 8-14 would seem to go along with this. Place your bets............

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