Model output discussion - late November

[feb1991blizzard]

Here comes a runner.

[BLAST FROM THE PAST]

53 minutes ago, StretfordEnd1996 said:

Mehh .. not nice looking charts out towards D7-10.. 

But hey every chance for twists and turns

You got to look at the whole movement, the HP to SW isn’t moving ENE it’s backing west and then it will ridge towards Greenland, so that is a chart looking to return cold over the UK from our NW then N.  PV displaced to NE

 

BFTP

Edited November 26, 2019 by BLAST FROM THE PAST

[ICE COLD]

19 minutes ago, bluearmy said:

Is this a roaring vortex across the NH ?

No it’s not . All the negativity on here today People saying the purple blob of doom is gonna bring weeks of zonal but when the pv is on the move constantly from one side to other not settling in one place . It gives us opportunities. Take the T174 chart on the 18z it’s to the nw now by T252 it’s moved again with ridge going towards Greenland. So no permanent place where the pv is settling. So we can still have decent shots at some form of cold . 

Edited November 26, 2019 by ICE COLD

[StretfordEnd1996]

By +240 an area of HP shows signs of trying to push towards Greenland (again)

Into deep FI doesn't quite happen but still would turn colder again

If 144+ is FI these days then what's 240+. DFI? Deep FI perhaps..

[swfc]

Deep fi on the 18z gets the jet way south and would be pretty potent in a month or so.still pressure trying to move east again!!!

[Snowman.]

7 minutes ago, ICE COLD said:

No it’s not . People keep saying the purple blob of doom is gonna bring weeks of zonal when the pv is on the move constantly from one side to other not settling in one place . Take the T174 chart on the 18z it’s to the nw now by T252 it’s moved again with ridge going towards Greenland. So no permanent place where the pv is settling. So we can still have decent shots at some form of cold . 

This seems like a good shoutout periods of zonal blow torch followed by more blocked periods.  Not the worst December pattern. 
 

[Mike Poole]

1 minute ago, Snowman. said:

This seems like a good shoutout periods of zonal blow torch followed by more blocked periods.  Not the worst December pattern. 
 

No, agreed decent pattern, we can work with that, but it could have been better, a lot better.  Key check for me is in the more zonal interludes is any strong jet aimed at the UK, or as I suspect to the south...would become more important as we approach the coldest period, one to watch...

[ICE COLD]

Just now, Snowman. said:

This seems like a good shoutout periods of zonal blow torch followed by more blocked periods.  Not the worst December pattern. 
 

No that’s right snowman , I’d rather have that set up than proper traditional zonal . At least it will be pretty cold by day and frosty at night . Not to wet either just a few coastal showers . 

[feb1991blizzard]

46 minutes ago, bluearmy said:

Is this a roaring vortex across the NH ?

This isn't great if i am absolutely bluntly honest.

 

If ever you need to draw a straight line and you haven't a rule handy, in this day and age you can just use the Atlantic Jet.

Edited November 26, 2019 by feb1991blizzard

[StretfordEnd1996]

GEFS

Looking verrryyy chilly out until D6/7

Thereafter looking a tad flat and a tad boring if I may say!

Over to tomorrow's runs now.. tomorrow's another day.  

[Allseasons-Si]

Hello,late to the party

a longish post coming up

we are still in November aren't we!!!,or at least i thought i was reading some post's in hear tonight

we have a short cold snap/spell this weekend/early next week,that looks a certainty now but beyond that we will have to ride out some more mobile weather but it's not your usual zonal SW'ly affair  

Knocker posted the 6-10 day 500mb anomaly chart earlier showing a more mobile pattern,yes that looks likely

but look at the 8-14 day 500mb chart,this shows the Azure hp cell migrating west to allow PM attacks from the NW

the NAO/AO reflect this over the next week to ten days but do look to rebound towards neg values again,will this be a short mobile affair?

there are still workings going on up top and the models wan't realize that yet until a few weeks down the line

here is a couple of strat charts i posted in the strat thread this morning,it is clear that there is some warming showing on the jma plots

10 hpa,mean zonal winds and e-p flux,the e-p flux there showing a wave 1 after a weak wave 2

all looks quiet interesting as we move into Dec

P.S,if you haven't been watching Gavsweathervids.com,then the final thirteenth winter update is quiet interesting as to regards of wet Novembers and Autumn in general.

GavsWeatherVids - UK Weather Forecasts And Latest News

WWW.GAVSWEATHERVIDS.COM

---

Daily weather forecasts and news for the United Kingdom, Europe and North America. Video and written forecasts covering 1 to 90 day timescales. Updated Daily.

 

 

 

 

Edited November 26, 2019 by Allseasons-si

[Jordan S]

No real change since yesterday This weekend a cold east then northeastly wind exacerbated by a low slipping southeast into France tightening the pressure gradient for a time Saturday for the south and southwest resulting in a fairly strong southeasterly then Easterly wind with some rain into the far southwest for a time perhaps. 

Midday Saturday

The high sat more or less over us come Monday with cold air trapped underneath..

This steadily modifying as the week progresses with the high slipping south to allow a more west then perhaps northwesterly flow into the north of the UK especially Scotland with perhaps rain coming back in by the end of next week

Wednesday 4th..

5th..

6th..

Of course a bit too far out for certainty on that but a cold 4-6 days looking likely for most at present from Friday with hard frosts and perhaps some freezing fog issues early next week.

[knocker]

The North Atlantic 300mb wind field (relevant because related to the imminent ingress of colder air from the north) and the surface analysis for midnight

Today the low will cross the country to be just east of the Humber by 1800. Initially rain areas will be around the fronts within the circulation but in the latter part of the day it will become concentrated near the low in the northern, and in particular north east, regions of England. This doesn't rule out rain over northern Scotland and heavy showers in the south west

Tonight the rain will continue to e concentrated around northern and central parts of England with heavy showers on the periphery bu by morning the colder air will reach northern Scotland as the occlusion starts to slide south

The occlusion and patchy rain continue to track south through Thursday with some wintry showers in the north and down eastern coastal regions as the low continues to move east

Friday will be a dry and much colder day than of late but with wintry showers in the north and eastern coastal regions. But to the west another frontal system is tracking ESE under the now negatively tilted ridge

By Saturday the shallow low is to the south west with occlusion straddled across Cornwall and Devon, so whilst the rest of the country has another dry and cold day after a widespread frost, some rain will effect these areas with quite a strong easterly wind. But another upper low has dropped into the western Atlantic initiating further downstream amplification of the subtropical high

By Sunday the Atlantic is very amplified as the ridge moves over the UK. So after a frosty start it will be another cold day with some wintry showers in th north and eastern coastal regions.

[knocker]

The evolution over the next five days was touched on last evening with subtropical zones amplifying and the tpv transferring to northern Canada but with subsidiary lobes. The process establishes a strong jet across the Atlantic and quite likely a N/S split in the UK. Better to evaluate this with the benefit of the GEFS

[knocker]

As hinted at last evening there is nothing simple about the current indications vis the future evolution as can be seen again with this morning's ext GEFS

Which features the tpv over northern Canada with the two outriders and strong westerly upper flow around the Atlantic subtropical high that is flexing it's muscles. Thus the flow veering in the eastern Atlantic

.

 

[knocker]

This morning's fax update has Saturdays front a tad further to the south west but the ecm still has the rain ingressing

[Ali1977]

Not exactly Zonal as some are saying is on its way, more like another cold shot if this were true. Arctic high, weak heights over Greeny, and a shot of WAA heaving north from the Atlantic - possible Spilt or another toppler? 

 

GFS mean at 240 similar in our neck of the woods but poles apart towards the Alaskan of the NH with the WAA on the ECM splitting the PV.

Edited November 27, 2019 by Ali1977

[bluearmy]

1 hour ago, knocker said:

As hinted at last evening there is nothing simple about the current indications vis the future evolution as can be seen again with this morning's ext GEFS

Which features the tpv over northern Canada with the two outriders and strong westerly upper flow around the Atlantic subtropical high that is flexing it's muscles. Thus the flow veering in the eastern Atlantic

.

 

Wouldn’t you say the tpv was Kara/Barents and Aleutian with Canada as the outrider ??

as I mused last night, I can’t see all three locales having.a strong segment so which is likely to be transient or miss out completely come the time ??

[Newberryone]

Difficult to extract too many positives for coldies from the 0z Ecm when it comes to the overall evolution for next week. After a chilly weekend there looks like being an uptick in temps again from early next week with high pressure anchored to the southwest and with only a hint of another pm incursion +240. At least precipitation levels should be way down. 

[Ali1977]

13 minutes ago, Newberryone said:

Difficult to extract too many positives for coldies from the 0z Ecm when it comes to the overall evolution for next week. After a chilly weekend there looks like being an uptick in temps again from early next week with high pressure anchored to the southwest and with only a hint of another pm incursion +240. At least precipitation levels should be way down. 

Yep, not much mid term for coldies but there’s a definite positive for all those areas prone to flooding so to that. It’s early Dec, and it’ll feel like it from tomorrow till mid next week so it’ll be nice to enjoy that and start the next hunt. 

[mountain shadow]

20 minutes ago, Newberryone said:

Difficult to extract too many positives for coldies from the 0z Ecm when it comes to the overall evolution for next week. After a chilly weekend there looks like being an uptick in temps again from early next week with high pressure anchored to the southwest and with only a hint of another pm incursion +240. At least precipitation levels should be way down. 

At least it's not flat zonal and any South Westerly zephers brief. 

With the buckled jet we still have the chance of Northerlies.

[knocker]

45 minutes ago, bluearmy said:

Wouldn’t you say the tpv was Kara/Barents and Aleutian with Canada as the outrider ??

as I mused last night, I can’t see all three locales having.a strong segment so which is likely to be transient or miss out completely come the time ??

Yes I did wonder about that myself and looking at the EPS is not a great help but I'm inclined to the Canadian lobe here . I also noted the warming at 50mb in this area

 

Edited November 27, 2019 by knocker

[northwestsnow]

3 minutes ago, knocker said:

Yes I did wonder about that myself and looking at the EPS is not a great help . I also noted the warming at 50mb in this area

 

Our old foe the canadian segment,while not as pronounced as the other 2 segments,still doing all the damage for those of a cold persuasion and preventing retrogression of the pattern.

Unless i am reading the chart incorrectly?

[bluearmy]

11 minutes ago, knocker said:

Yes I did wonder about that myself and looking at the EPS is not a great help but I'm inclined to the Canadian lobe here . I also noted the warming at 50mb in this area

 

 

5 minutes ago, northwestsnow said:

Our old foe the canadian segment,while not as pronounced as the other 2 segments,still doing all the damage for those of a cold persuasion and preventing retrogression of the pattern.

Unless i am reading the chart incorrectly?

the eps has a discreet Canadian segment which is different to gefs and I suspect would be more sustained in situ

of course knocker posts a six day mean ......I wonder what the extended eps does with that arctic weak highi anomoly late on ........

 

Edited November 27, 2019 by bluearmy

[northwestsnow]

8 minutes ago, bluearmy said:

 

the eps has a discreet Canadian segment which is different to gefs and I suspect would be more sustained in situ

of course knocker posts a six day mean ......I wonder what the extended eps does with that arctic weak highi anomoly late on ........

 

The mean at day 10 looks similar to last nights with perhaps a little more emphasis on a PM airflow down the line..

Still a large neg pressure anomaly to the NW which is always the thorn in coldies side..