Model Output Discussion 1200 hrs 15/11/14

[IDO]

D16 on the GEFS and much as before; a few clusters hinting at amplification, some flatter but most with the ridge/trough shortwave flow, though definitely showing a slower movement east of the pattern:

 

 

Good consistency with the GEFS for a period from next week of PM and TM flow for the foreseeable with some chatter in the background that maybe a more meridional flow will develop. 

Edited November 27, 2014 by i'm dreaming of...

[pip22]

Try the 1st of December for the Highlands.

 

Wow!!   One little change in the models could bring a huge difference in the weather in the few days. That is one thing I love model watching!! 

Edited November 27, 2014 by pip22

[Smiler1709]

I don't why I'm feeling this but I just think the models are gonna go BOOM soon! And show us some real winter charts. I'm thinking were gonna get a north westerly to northerly with high pressure building around Greenland allowing us to get our bitter easterly. I really think were on the cusp on something very noticeable.

[Thundery wintry showers]

A mainly anticyclonic start to December then- we can't really deduce much from that regarding the winter's prospects, since December 2013 started anticyclonic but so did December 1962.  

 

A grey and damp day is likely tomorrow but into the weekend we should get some drier air heading in from the continent which will allow some sunshine to come through on Saturday, though not everywhere will see much sun (due to patches of cloud being hard to forecast in these late autumn/winter anticyclonic situations).  On Sunday it will turn cloudier from the north-west generally, except in the south-east of England and East Anglia, due to an advancing Atlantic weather system.  

 

The brief north-westerly incursion on the 1st/2nd December should bring some sleet and snow showers to many parts of Scotland, though mainly to the north of the Central Lowland belt from Edinburgh to Glasgow.

https://max.nwstatic.co.uk/gfsimages/gfs.20141127/12/108/h500slp.png

 

It is looking like we will break the annual Central England Temperature record if December comes in even slightly above average (whether you're using Hadley or Philip Eden's alternative continuation of the series) but this is not a given because the anticyclonic weather will probably produce a fair amount of "inversion cold" in southern Britain.  Generally, in spite of Scotland being more prone to brief wintry incursions from the north-west in this setup, Scotland is likely to be significantly warmer than average but the further south you go, the more likely it is to be close to or a little cooler than average.  I think that sunshine totals for early December are likely to be above normal in eastern Scotland and north-east England, to the lee of high ground, while western Scotland and most of Ireland will be dull.  For Wales and the rest of England sunshine totals are much harder to predict but it's almost a given that it will be much drier than average for a while.

 

The NOAA 8-14 day anomalies imply a strong mid-Atlantic high:

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

This could potentially set us up for some northerlies towards mid-December (like the mid-Atlantic high setup in late February 1988, February 1999 and late January 2003) but unless the high heads north towards the Greenland/Iceland region we're only looking at 36-48 hour topplers at the most.  On the whole temperatures are likely to rise above the seasonal norm in central and southern Britain if that setup verifies, with any chilly northerlies or north-westerlies more than offset by the milder interludes associated with tropical air heading around the northern flank of the high, but they may fall close to average in Scotland (especially the north of Scotland).

Edited November 27, 2014 by Thundery wintry showers

[Buxton Codge]

A really nice day 6 from the UKMO 12z, I can see potential from there...

 

 High pressure will move south from that position and bring a return to milder/cloudier Atlantic weather

[Mark Neal.]

High pressure will move south from that position and bring a return to milder/cloudier Atlantic weather

Care to explain why,? Any Charts to back up this comment?

[fergieweather]

NB - 12z UKMO-GM is a fallback run so 'genuine' fields not visible for now. The 12z E4 will also be delayed.

[Cloud 10]

 High pressure will move south from that position and bring a return to milder/cloudier Atlantic weather

 

....or,the ridge off the Eastern seaboard will join up with the Arctic high,sending a chunk of the vortex towards the UK.

 

[Great Plum]

NB - 12z UKMO-GM is a fallback run so 'genuine' fields not visible for now. The 12z E4 will also be delayed.

A fallback run? Is that like a default setting?

Is the 12z E4 the ECM?

Thank you

[pip22]

....or,the ridge off the Eastern seaboard will join up with the Arctic high,sending a chunk of the vortex towards the UK.

 

UN144-21.gif

Another option is the Azores could decide to go south-west instead and bring the low from the north towards us and at the same time the another high at Newfoundland joins up with the Arctic one. then we would expect cold weather from the North.  

Edited November 27, 2014 by pip22

[Buxton Codge]

Care to explain why,? Any Charts to back up this comment?

 

The roaring northern arm of the jet. High pressure ain't going to go further north.

[Smiler1709]

High pressure will move south from that position and bring a return to milder/cloudier Atlantic weather

Can you please explain how you have come to that assumption?

Just seen your reply but high pressure will also influence the jet and just as much chance to drive it south.

Edited November 27, 2014 by Smiler1709

[Cloud 10]

A fallback run? Is that like a default setting?

Is the 12z E4 the ECM?

Thank you

 

I think Ian means The Euro 4.

[Buxton Codge]

Can you please explain how you have come to that assumption?

Just seen your reply but high pressure will also influence the jet and just as much chance to drive it south.

 

Quite clearly evidenced on the GFS 9 panel charts. The northern arm of the jet stopping any UK cold spell for the next 2 weeks

 

http://www.wetterzentrale.de/pics/avnpanel2.html

[Gael_Force]

A fallback run? Is that like a default setting?

Is the 12z E4 the ECM?

Thank you

 

Not the ECM - the short range Euro4.

[Gael_Force]

Quite clearly evidenced on the GFS 9 panel charts. The northern arm of the jet stopping any UK cold spell for the next 2 weeks

 

http://www.wetterzentrale.de/pics/avnpanel2.html

 

Since when did 9 days come to reflect 14?

[Barry12]

Day 7 is good on the ECM, nice arctic high and the Polar Vortex has moved away from Greenland

 

 

I think it's going to be very interesting over the next couple of days...

[johnholmes]

Netweather said a weakened stratospheric vortex and Sudden Stratospheric Warming (SSW) will lead to a  “very disturbed tropospheric polar vortex and negative NAO [negative Arctic Oscillation].

Forecasters Ed O’Toole and Tony Wells warned winter will be hit by major cold snaps rivalling the worst winters in British history.

 

Think Netweather must be getting the UK mixed up with the North East of America LOL!

 

BC, If you believe any so called quotes in the DE then good luck to you. The reality is that nothing of the kind was said by anyone at Net Wx but don't let that stop a good DE story.

[gottolovethisweather]

I'm not one for commenting on one run in isolation, especially as it still rolls out but the ECM looks a beauty. A dry start and pretty cold for a few days to the around the 4th December and from then on, this run suggests a NWly could have greater influence on the general UK synoptic situation. The latter frames need watching closely right through from D6 to D10 because during this timeframe a few parts could well see some of their first proper snowfalls. I also like how the Arctic high gets shoved ever so slowly from East to West during the middle part of this run, in turn this allows for a chunk of the PV to drift closer towards our shores.   I've now looked at the whole run and it slightly flatters to deceive by D8 onwards, however I hope this trend for the NH profiling up to then continues unabated, if so December could be about to get very interesting, all IMHO.

 

 

Edited November 27, 2014 by gottolovethisweather

[Polar Maritime]

I have deleted/moved a few post, Please stop the 1 liners and add a little meat to the bones so to speak. And keep on topic

 

Thanks PM. 

Edited November 27, 2014 by Polar Maritime

[nick sussex]

If you like exciting weather then the ECM is not for you. Taken at face value mainly dry especially towards the south, a few fronts brushing past the north, some frost and fog at times.

 

Theres never enough upstream amplification to bring the Arctic high into play,whether the pattern upstream is as flat as suggested after T144hrs time will tell.

[Buxton Codge]

Good ECM tonight if you are looking for a dry December. Probably fairly mild too with little in the way of frost

 

http://www.wetterzentrale.de/pics/Recm2402.html

[Hocus Pocus]

Good ECM tonight if you are looking for a dry December. Probably fairly mild too with little in the way of frost

 

http://www.wetterzentrale.de/pics/Recm2402.html

Two points, firstly  since we're still in November how does that equate to your point and secondly no one knows just where the High pressure cell will locate itself just yet so we could end up with a frosty or mildish high.

[Polar Maritime]

Ok. Let's try again.

[Snowman.]

Polar heights causing a distress in the already damaged vortex while we continue to sit under the influence of high pressure.

 

Gradual signs of the PV lobe maybe leaving Greenland.

 

Edited November 27, 2014 by SN0WM4N