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Model Output Discussion 1200 hrs 15/11/14


phil nw.

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Posted
  • Location: st albans
  • Location: st albans

we have another day before the ops get this atlantic depression into a timescale where they should get it right re whether it pushes across and cuts off the arctic high. given that the arctic high is the other player in this conundrum and there is reason to believe that a volte face could be possible. definitely the less likely scenario but certainly not out of the question.

 

as steve says, if the arctic high gets this side of the pole as far as svaalbard then the ops are all wrong thereafter.  i dont expect the ops to shift suddenly on this but there are GEFS members that are definitely showing this as a possibilty. tomorrow is not crucial but it could be fun. at the moment i expect the northern arm to be too strong.

 

for good measure the day 10 ECM leaves us with a smile, the gate to the garden path ajar .....................

Edited by bluearmy
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Posted
  • Location: North Yorks/Lancs border 180m asl
  • Location: North Yorks/Lancs border 180m asl

 

Yes Captain It looks like a high building around our latitude is favourite which isn't a bad holding pattern.

Some crisp frosty weather quite possible depending on positioning.

As long as we maintain some low pressure in S.Europe this will help to prevent a sinker.

We then either get the northern jet firing up flattening the pattern with the return of the westerlies or the block building north or north east which would bring in the growing continental cold from the east.

Normally the first  option would be the form horse but with the weaker  pv this year then it really is 50/50 at present.

 

I did raise the potential Atlantic trough on ECM earlier today, and the 12z shows this heading towards Iberia at t240.  Does this help prevent the sinker that you refer to? 2 runs now.

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Posted
  • Location: Newton in Bowland
  • Location: Newton in Bowland

 

Yes Captain It looks like a high building around our latitude is favourite which isn't a bad holding pattern.

Some crisp frosty weather quite possible depending on positioning.

As long as we maintain some low pressure in S.Europe this will help to prevent a sinker.

We then either get the northern jet firing up flattening the pattern with the return of the westerlies or the block building north or north east which would bring in the growing continental cold from the east.

Normally the first  option would be the form horse but with the weaker  pv this year then it really is 50/50 at present.

 

Would it be a sinking high over time though Phil, as that looks a possibility to me?

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Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

I did raise the potential Atlantic trough on ECM earlier today, and the 12z shows this heading towards Iberia at t240.  Does this help prevent the sinker that you refer to? 2 runs now.

Yes heath on that chart there still some energy going under the block towards Iberia.Of course at that range it could  well change.

It will be Interesting to see how the models split the jet across the Atlantic in the coming days to see how they develop the high around our local.

@hocus pocus

Yes it could that's why we need to see future undercutting of the jet towards the Iberian area.

It's just a case of watching the runs over the next few days to see how this evolves.

Edited by phil nw.
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Posted
  • Location: Horsham, West sussex, 52m asl
  • Location: Horsham, West sussex, 52m asl

Maybe im just wearing snow goggles but i would like to see another couple of frames of the ECM as in the last 3, the HP starts to push towards greenland with the LP either side dropping south.

Unlikely probably but stranger things have happened...

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Posted
  • Location: Strood, Medway
  • Location: Strood, Medway

Not sure if this has been posted or not but here but this was posted on Twitter from Cohen AER/NSF site showing below average temps for parts of the U.K during DJF, based in part on the OPI.

 

post-1952-0-43460300-1416944697_thumb.jp

Edited by Hellboy
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Posted
  • Location: Freshwater Isle of Wight
  • Location: Freshwater Isle of Wight

Tonights ECM offers a continuation of the trend of recent runs with low pressure establishing itself to the south of the UK and a elongated ridge becoming established across the Midlands and the north. As the flow over the UK gradually backs the warm air being drawn NW from N Africa is eventually replaced by colder drier air from further east. This colder drier air is likely to filter over much of the UK (providing the ridge remains in place) leading to much frost and freezing fog. As it will be early December by then and provided skies are clear the frost could persist all day in the shade and even accumulate. Also with the prospect of persistent freezing fog there could be significant rime deposits. It could end up being quite a wintry scene unlike many of the more recent early Decembers with the odd exception of course.      

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Posted
  • Location: chellaston, derby
  • Weather Preferences: The Actual Weather ..... not fantasy.
  • Location: chellaston, derby

Barry95 steve

On tablet cant quote large posts so ill address the points made.

Barry, you have a point, the euro high might not die, it has been expected and has so far failed to do so. I do think though that this time its time is up as theres strong cross member support for it.

However, its looking likely that the azores ridge will replace it. So perhaps no quick cold evolution but as long as theres a high somewhere close to the uk something cold MIGH evolve. Of course it might just fizzle out and we have ordinary average weather.

Steve, yep i take your point but as you say its one possibility. Im not looking for cold, nor mild even if i like mild, im looking for most likely because thats what we are most likely to get. Ill take whatever is thrown at us.

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Posted
  • Location: Peterborough
  • Weather Preferences: Snow and frost in the winter. Hot and sunny, thunderstorms in the summer.
  • Location: Peterborough

Solid trend for a week 2 UK high

EDM1-192.GIF

EDM1-240.GIF?25-0

But will events prior to this prevent this trend from happening. The GFS ens, EC32 and metoffice updates support settled weather with frost and fog developing in week 2 so there is a good chance of some proper chilly and settled weather actually verifying.

Edited by Captain shortwave
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Posted
  • Location: portsmouth uk
  • Weather Preferences: extremes
  • Location: portsmouth uk

It's pretty clear that nothing is set in stone!.

but the high over uk is spot on at this time of year,

and unlikely to be a sinker.

either it pushes north west or North East or East or even west although there's lots energy in the Atlantic.

Either way nothing remotely mild!.

cold surface lid over the uk with every chance of height retrogression into a more favourable area.

With tetis idea being a very good possibility.

The heights to the northeast we have now,

gets sucked through the Arctic cycle,

heights build over the uk!

low pressure starts to take center stage to or East then possible that our heights retrogress west to block the Atlantic,

or retrogress to Greenland opening the door to Arctic Siberia or straight easterly either way nothing mild.

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Posted
  • Location: portsmouth uk
  • Weather Preferences: extremes
  • Location: portsmouth uk

Solid trend for a week 2 UK high

EDM1-192.GIF

EDM1-240.GIF?25-0

But will events prior to this prevent this trend from happening.

Better than Atlantic dominance and perfect start to winter.

I'm now much much more confident of a more favourite retrogression and colder still it may well be the uk heights will be stubborn but let's not forget many a winter with heights over us has down the line thrown some at the excitement.

The lows to our west being fed by the vortex don't have anywhere to go but southeast.

Could possibly see charts resembling 1962/63 with massive blocks building to our nw to our ne but it's looking better now than 3 days ago.

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Posted
  • Location: Camborne
  • Location: Camborne

NOAA 6-10 Hp Siberia-pole Scandinavia ridging down through the UK in a pincer movement with the HP on the eastern seaboard. Trough Canada to just SE of Greenland. The GEFs and ECM not dissimilar  which basically translates on the surface to HP western Atlantic and Scandinavia with a quite south easterly over the UK with temps a wee bit below average  Later the GEFS and NOAA  8-14 weaken the Scandinavian HP, and move it east, and also weaken the Canadian trough and shift the Atlantic HP slightly east. No sign of any cold on the horizon.

 

post-12275-0-45267500-1416949491_thumb.g

post-12275-0-81959800-1416949499_thumb.g

post-12275-0-39837900-1416949519_thumb.p

post-12275-0-68699800-1416949527_thumb.p

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Barry95 steve

On tablet cant quote large posts so ill address the points made.

Barry, you have a point, the euro high might not die, it has been expected and has so far failed to do so. I do think though that this time its time is up as theres strong cross member support for it.

However, its looking likely that the azores ridge will replace it. So perhaps no quick cold evolution but as long as theres a high somewhere close to the uk something cold MIGH evolve. Of course it might just fizzle out and we have ordinary average weather.

Steve, yep i take your point but as you say its one possibility. Im not looking for cold, nor mild even if i like mild, im looking for most likely because thats what we are most likely to get. Ill take whatever is thrown at us.

 

No worries Mushy, the ECM is the most likely solution with perhaps some more amplification out of it.

 

the NAVGEM route is about 15%.

 

If the jet does get through the block then whilst it stays pretty chilly at the surface & will open the start of Winter below average - the next chance of cold 'uppers' would come around day 12.

 

As ever the UK have to be patient, but nicely poised for Day 1 of Winter 14.

S

Edited by Steve Murr
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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Good ens agreement from ECM for high pressure to build next week giving some cold nights with some fog in places by day temps should be around average providing your not stuck under any fog

 

EDM1-168.GIF?25-0EDM1-192.GIF?25-0EDM1-216.GIF?25-0EDM1-240.GIF?25-0

EDM0-168.GIF?25-0EDM0-192.GIF?25-0EDM0-216.GIF?25-0EDM0-240.GIF?25-0

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Posted
  • Location: Head in the clouds somewhere near Avondale, West Auckland
  • Weather Preferences: Storm-force northeasterly(with a high tide!).Blizzards.Sunny summer
  • Location: Head in the clouds somewhere near Avondale, West Auckland

Not sure if this has been posted or not but here but this was posted on Twitter from Cohen AER/NSF site showing below average temps for parts of the U.K during DJF, based in part on the OPI.

 

It's hard to credit that a region as small as the UK and Ireland could have such a diversity of temperature anomaly given as an average over 3 months. Looking also at France (cold east, milder west) and Spain, I wonder does it indicate a complex situation with HP often near the NW of these islands, low pressure over Spain and France, with bursts of east winds bringing cold across England. But not sustained or widespread?

Or a settled scenario with alot of blocking close or over these islands and the east of England getting any colder air much more often than other areas. It certainly doesn't indicate much in the way of any cold northerlies. Maybe it also indicates HP over north and east Europe, but not Greenland, jet going around the high, coldest air in these islands in England from east winds making it that far west sometimes. Western, and northern areas not getting the cold penetrating

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Posted
  • Location: Oyne Aberdeenshire 120m asl
  • Weather Preferences: SNAW
  • Location: Oyne Aberdeenshire 120m asl

Here's my latest weekly synoptic outlook, looking at the likely weather patterns affecting the UK and Europe over the coming 14 days. A blocked pattern continues across much of northern Europe:

 

http://www.netweather.tv/index.cgi?action=news;storyid=6313;sess=

 

Here's an excerpt from the discussion with regards to a more anticyclonic and increasingly chilly picture from next week:

 

Early next week (start of December) something more seasonal, today’s operational runs of GFS, UKMO and ECMWF  erode this belt of high pressure across the UK from the northwest, as fragment of colder air breaks SE from the vortex over Greenland. This allows the westerly jet to sink SE across the UK, introducing colder air from the northwest across the UK on Monday into early Tuesday. Then most models agree on high pressure building back in from the west by mid-week next week. And with the colder airmass that arrived on Monday from the NW still hanging around, the anticyclonic conditions are likely to bring a chilly feel  - with a risk of widespread overnight frost and freezing fog forming. 12z GFS and ECM operationals and ensembles this evening point towards this anticyclone hanging around until the end of the next week (day 10)

Thats already a million times better than anything we had last winter...and with the NH looking like it does and has done for some time now i think the UK will see at least one major cold outbreak this coming winter...less not forget that even in an average winter the UK can see some very wintry weather with snow for many....and as a way to brighten my mood today im just settling down to "THE DAY AFTER TOMORROW" Now how many of us would like to see something like that from the models this winter??

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Posted
  • Location: Windsor
  • Weather Preferences: Snow and cold
  • Location: Windsor

It's a fascinating period for model watching over the next few days. All the models have subtle differences in the positioning of the high pressure, we just need a nudge from the Scandinavian high westwards and a few tweaks here and there to provide with much colder synoptics.

 

Look forward to the morning output to see which way the models swing! :)

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Posted
  • Location: Camborne
  • Location: Camborne

Interesting P this evening as from T144 onwards it has the low and Azores ridge moving east in tandem bringing a very marked warm.cold split over Europe. Not going to plan here.

Charts courtesy weatherbell.com

 

 

post-12275-0-59145400-1416957435_thumb.p

post-12275-0-75779900-1416957442_thumb.p

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