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This is the focused model discussion - please only post about the model output. 

For a more laid back, bantery model discussion please use the Cold hunt - models and banter thread.

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The warmer air creeping east today with the font And to digress for a moment. I was in a taxi just now and the driver started wittering on about how he loved cold weather. I thought, '

Interesting morning and really encouraging IMO in terms of the set of model suites we were looking at on Thursday and Friday being chipped away at then collapsing into something else late Friday into

What we need to see is exactly what you are seeing here, though by pacific trough I'll translate that as Aleutian low. We need the pattern to retrogress to pull the power out of the Canadian lobe, and

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45 minutes ago, chrisbell-nottheweatherman said:

Apologies for the delay, but could you explain further,please Malcolm?

I'm not sure there is much to explain Chris. It was merely an observation that the analysis in the lower stratosphere is similar to the 500mb in the troposphere

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Just now, knocker said:

I'm not sure there is much to explain Chris. It was merely an observation that the analysis in the lower stratosphere is similar to the 500mb in the troposphere

Cheers Malcolm - I read more into it than there was!  Would this suggest that the stratospheric and tropospheric vortices are more coupled than some here have speculated?

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1 minute ago, chrisbell-nottheweatherman said:

Cheers Malcolm - I read more into it than there was!  Would this suggest that the stratospheric and tropospheric vortices are more coupled than some here have speculated?

One would think so but this much of this is above my pay grade Chris.

A neat geostationary at 1500 as the sun starts to set  And what is waiting in the wings?

geo.thumb.JPG.3b7fb0a80598b01921ce4462bff0201e.JPG

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What was quite interesting with 06 GEFS. although there was no particularly obvious blocking the distribution was such as to move the cold air closer to the NE. Await to see if this continues in a minute

gefs_t2ma_5d_nh_53.thumb.png.f584fd310293ca03ba34a04599fdba6c.png

Edited by knocker
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30 minutes ago, knocker said:

What was quite interesting with 06 GEFS. although there was no particularly obvious blocking the distribution was such as to move the cold air closer to the NE. Await to see if this continues in a minute

gefs_t2ma_5d_nh_53.thumb.png.f584fd310293ca03ba34a04599fdba6c.png

I'm not seeing much indication of the cold air associated with the lobe over eastern Canada entering the Atlantic on that output; am I mistaken? 

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1 hour ago, chrisbell-nottheweatherman said:

Cheers Malcolm - I read more into it than there was!  Would this suggest that the stratospheric and tropospheric vortices are more coupled than some here have speculated?

My observation would be that 150 his charts on Berlin are nearly always the same pattern as the 500 how trop output

for the trop and lower strat to be different would take some doing - you can’t have 3” snow in your front garden and nothing in your back garden - 

 

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3 minutes ago, bluearmy said:

My observation would be that 150 his charts on Berlin are nearly always the same pattern as the 500 how trop output

for the trop and lower strat to be different would take some doing - you can’t have 3” snow in your front garden and nothing in your back garden - 

 

I must have misunderstood the discussion.  I thought there was a suggestion that the stratospheric vortex divide hadn't affected the tropospheric vortex, which was based on the thought that the two weren't coupled.

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GFS and ECM are similar at T120:

gfseu-0-120.thumb.png.565b3fd2f5dc2de4d5993c5486bb10a8.png1959570693_ECE1-120(2).thumb.gif.16b08ec60bab8702a18eab26f113a9fc.gif

However, the GFS splits the energy close to the UK, whereas ECM has a spoiler low that inhibits that mini-ridge push. Small differences but at T144:

1862182862_gfseu-0-144(1).thumb.png.5814f5f21da09ef3bdb8518d36617009.png617998325_ECE1-144(2).thumb.gif.ccc0cc0cbaf008f4e2752726843eb757.gif

ECM pushes the pattern east along with the Siberian High, whereas the GFS becomes more blocky and keeps the cold in situ.

Fine margins!

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This evening's fax charts for Thursday/Friday

PPVI89.thumb.gif.00e16a56aba1fb2d6fa23cb02d3d471c.gifPPVJ89.thumb.gif.742dad4bfd8387737e918e5cc114495c.gifPPVK89.thumb.gif.d8deb256c299502c6169a00ade40f20f.gif

And the ecm on the front/precipitation band.

Thursday 1800 lying across Wales and the south west/

By midnight Wale to the south east with the heaviest Sussex and Kent. Could be of snow as it moves NE Knife edge

By 06 the weakening front is N Wales to the south east so possible back to rain

 

 

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1 hour ago, knocker said:

This evening's fax charts for Thursday/Friday

PPVI89.thumb.gif.00e16a56aba1fb2d6fa23cb02d3d471c.gifPPVJ89.thumb.gif.742dad4bfd8387737e918e5cc114495c.gifPPVK89.thumb.gif.d8deb256c299502c6169a00ade40f20f.gif

And the ecm on the front/precipitation band.

Thursday 1800 lying across Wales and the south west/

By midnight Wale to the south east with the heaviest Sussex and Kent. Could be of snow as it moves NE Knife edge

By 06 the weakening front is N Wales to the south east so possible back to rain

 

 

Hi Knocks

where would you think the precipitation would extend to according to this

image.thumb.png.c6a5280c8bd71181d221f8ebf776fe56.png

 

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2 minutes ago, winterof79 said:

Hi Knocks

where would you think the precipitation would extend to according to this

image.thumb.png.c6a5280c8bd71181d221f8ebf776fe56.png

 

Roughly North Wales to the Wash with it becoming patchy but this is really best guess scenario for 48 hours hence.

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The 1800 geostationary WV image shows the clearance behind the front and the wodge of showers to the NW quite well

geo.thumb.JPG.77a7ee34d8248632b43a4d61076ac529.JPG

And quite a bit of rain on the 2000 chart

20.thumb.gif.4a6201aa7f6d5398606c54bc066852d1.gif

 

Edited by knocker
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1 minute ago, knocker said:

The 1800 geostationary WV image shows the clearance behind the front and the wodge of showers to the NW quite well

geo.thumb.JPG.77a7ee34d8248632b43a4d61076ac529.JPG

 

Great image not sure if the showers would penetrate further than the western districts of England but great for Ireland et al

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48 minutes ago, knocker said:

The ext EPS mean anomaly has quite strong ridging of Azores HP north east over the UK into southern Scandinavia with temps around average

 

Yes signs the azores high wants to ridge NE towards the UK - in time we may see it succeed moving into southern scandanavia and then build NW pulling in a colder easterly feed - would tie in with Met Office thoughts, may have to go through a milder blip between 5-10 Feb first.

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Thought I'd stick this here as it will be buried by moans and sniping in the other thread as the 18z rolls out. Based on 18z icon and 168 UKMO charts, so looking for some other thoughts!

 

Seems to have been a running theme so far. Models keen to push systems through the UK taking us into a milder theme, but as we get closer to the time they start to show troughing down through the UK to the south. It's a bit of a stalemate situation, especially with the Siberian high now out to the east preventing any further inroads.

 

As we have seen, it's not a lot of good for us if it's prolonged snow you are looking for as the trough is just too far east leaving us in a cold, yet not cold enough, NNW to NW flow. The situation almost looks like a phase 6 MJO setup on our side.

 

If the Canadian vortex ever decides to take a hike west or towards Siberia then we could see some action; towards Siberia would be good as it would drive very cold air down the eastern side of the high pressure as the latter pushed west.

 

On the other hand, it may be a case of waiting for it to wane enough as it naturally weakens into February.

 

Finally, we could be left with the stalemate for a while yet. I thought it looked like the UKMO 166 charts showed some signs of disruption so perhaps the cold but not cold enough pattern could stick for a while yet.

 

We shall see.

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The 500mb and surface analysis for midnight and the 0300 WV image

eur_full_500.thumb.gif.8e06755fa0442fe48b82ba9016f7e369.gifPPVA89.thumb.gif.16e56f8657c850afc62925bf64493610.gifgeo.thumb.JPG.39c53e93b099e8a5623bc43659abf749.JPG

A cold and icy start to most places this morning  with some hefty wintry showers of rain, hail or snow in western regions. particularly the the NW and some rain and snow lingering in the east. (see sat. image) The latter will soon clear but the showers will continue through the day but less frequent in England and Wales, Apart from this generally sunny but cold

PPVE89.thumb.gif.bd70ca7432fb787d1b86629ccc077780.gifs12.thumb.png.a777a6b05b448d00953585300b9c865d.pngs18.thumb.png.afef15f4dc0d45145cb39bf91c9e56a4.png

A few showers may linger in western regions overnight but with the clear skies temps will quickly start to fall and by Thursday morning there will be a widespread frost with some freezing fog patches around. But by 0600 rain from the occlusion associated with the low west of Ireland will be effecting south west Ireland and the scilly Isles.

PPVG89.thumb.gif.d1fbed236cba0d3336b5749d31d6dc2f.gif642201424_sr06.thumb.png.99548a58a182573f33b474d84edf65bc.png1651544277_minth.thumb.png.e8b8d55eb3934bf27e1826947ec9bd71.png

Through Thursday the rain belt will track north east turning to snow as it hits the entrenched colder air and by 1800 will start to swivel as the low to the west tracks south east

PPVI89.thumb.gif.2c0f18893bb02e5642e85cbb7f84c1b5.gif661029197_maxt.thumb.png.456484d9a3efaf1a09d2067d983bc4a5.png933443992_sr12.thumb.png.9493a6d91202b9b1f136af1897f920b0.pngsr15.thumb.png.790f6b463c9f59e7228e857c8dd958dc.pngsr18.thumb.png.2ce67ba1c10c6257c6ede066b2bff368.png

The low will continue to track into western France overnight Thursday and the snow belt will continue to swivel and move slowly north but the front is weakening and the snow likely to become lighter and more patchy. The intensity and extent of the snow is still tricky on this slow moving front so even now nothing is set in stone

PPVJ89.thumb.gif.0d8719c726176e051fb427032c7a85fc.gifPPVK89.thumb.gif.937042d6f2e37b07f26e9e770c3a8b99.gif

gfs_ptype_slp_uk2_9.thumb.png.52331b478bb6149e18d98b53156b80b2.pnggfs_ptype_slp_uk2_10.thumb.png.3e33dd8942a1cc3fdd0058528bae83c9.pnggfs_t2max_c_uk2_12.thumb.png.49311271b9c6ed7befedb08cfe82e3e4.png

The low moves away east and any residual snow clears by Saturday resulting in a very  cold weekend with widespread frosts but some patchy rain, sleet and snow may encroach western regions late Saturday into Sunday courtesy of frontal systems associated with a low pressure area near Iceland. The front(s) are quite active and developing waves could well bring some more snow to the north on Sunday.

gfs_z500_vort_natl_19.thumb.png.d048eb6af0bf773ce0884fb02e05121e.pngPPVM89.thumb.gif.d30c6dd9ffab56833d2ddb9bcc604b92.gifPPVO89.thumb.gif.21ce122d25ddfdb5dde4ef9f12c1ddca.gif

gfs_t2max_c_uk2_16.thumb.png.709a9595f028d57cb4cba26685465095.pnggfs_t2max_c_uk2_20.thumb.png.337c45831d2425a775a7058459729134.png

Edited by knocker
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To continue briefly with the gfs. At the beginning of next week the trough is relegated south east as the subtropical high amplifies north east over the UK  The ridge/high pressure proves to be quite resilient to the pressure exerted from the west and frontal systems only manage to encroach far enough to effect the north west during the rest of the week which remains cold, more particularly over England and Wales

gfs_z500_vort_natl_28.thumb.png.17c4faf7ee0b3057199e1c9d913f51b2.pnggfs_z500_vort_natl_32.thumb.png.8bdcb769ec8ae69bce1384df2b6e28bf.pnggfs_z500_vort_natl_38.thumb.png.3ca1985ed75070ce24e9f9fca48c7abd.png

Edited by knocker
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The ecm has quite an active wave on the front on Monday which could give a fair amount of snow over the higher ground in the north, After that clears quickly early Tuesday some ridging from the south west before the next system pushes in late Wednesday And that the energy battling against the ridge more or less sees out the week

t138.thumb.png.520bd2a4c3a722bac8088a3127a08b4a.pngt186.thumb.png.ab69581d6da2f46328f06602e916db93.png

Edited by knocker
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