Model Output Discussion - cold spell to end Autumn

[Daniel*]

22 minutes ago, Spah1 said:

What do we make of this little guy???

Polar Low.

[Met4Cast]

1 minute ago, blizzard81 said:

120hr fax agreeing with the ukmo raw. 

They usually do, I can't remember the last time the FAX chart was modified from the UKMO raw output at 120hrs.

Incredible runs again, as always snow detail will remain elusive but boy, are we getting close!

[I remember Atlantic 252]

 

Edited December 4, 2017 by I remember Atlantic 252

[bluearmy]

Interesting ........ ec46 week 3 shows rising height anomoly to our ne ...............

awaiting more than the Icelandic view .....

[onepingonly]

Normally over in the regional forums so would anyone mind a quick explanation of what a slider is? Hearing it a lot. Thanks.

[Nick F]

The arctic blast from Friday seems to be taking on an increasingly NWly wind direction compared to previous more Nly runs, so looks like western coastal areas most prone to frequent snow showers Friday and Saturday, with snow showers getting through the Cheshire Gap to the Midlands too. Though by Sunday showers tending to die out in the west and confined to eastern coasts

Also of note is pretty decent T850s for a NWly across the board, -10C as far SE as Kent on Saturday morning.

Some low maxima at the weekend too, bearing in mind GFS maybe too high by a degree or two.

On to the slider lows, no luck with the first one, but second time lucky?

 

Edited December 4, 2017 by Nick F

[Ice Day]

1 minute ago, bluearmy said:

Interesting ........ ec46 week 3 shows rising height anomoly to our ne ...............

awaiting more than the Icelandic view .....

Very interesting, deep FI on the GFS has touched on that a few times recently......although to be fair GFS FI touches on every solution from one run to another!   

[Derecho]

A curiosity further afield...

Anyone noticed that high over the north pole? It's pretty much been a permanent feature in some way since mid November.

Very unusual

Edited December 4, 2017 by Quicksilver1989

[Man With Beard]

Fresh EC clusters are out, and at last a second cluster in the D11-D15!!

T144 - the op has most support, but various other slider clusters tonight, I think every part of the country is in the sweet spot on one of them!

[nick sussex]

The latest MJO update has been issued by NOAA.

The CPC velocity potential based and RMM MJO indices indicate an enhanced MJO signal over the Maritime Continent. Some eastward propagation has been observed over the past few days.

 Dynamical and statistical forecast models depict fairly canonical MJO evolution over the next one to two weeks, with the enhanced phase shifting eastward over the West Pacific, and suppressed convection developing over the Indian Ocean.

 Tropical cyclogenesis is possible in Week-1 over two regions where MJO-related convection is ongoing: the Bay of Bengal and the western North Pacific.

 The current and forecast MJO evolution favors anomalous troughing near the Aleutians and over east-central North America throughout the remainder of the month.
 

Given they expect the current Aleutian trough and central east USA trough pattern to last throughout December as long as you can maintain enough amplitude in that eastern USA trough and with help from weak height rises to the ne then the UK should continue to see chances for further cold and snow.

[blizzard81]

1 minute ago, Man With Beard said:

Fresh EC clusters are out, and at last a second cluster in the D11-D15!!

T144 - the op has most support, but various other slider clusters tonight, I think every part of the country is in the sweet spot on one of them!

Cheers MWB. Any chance you could post the 11 to 15 please. Impatient me lol. 

[Man With Beard]

3 minutes ago, blizzard81 said:

Cheers MWB. Any chance you could post the 11 to 15 please. Impatient me lol. 

D12 looks interesting - main cluster once again could have Atlantic ridge

Edited December 4, 2017 by Man With Beard

[Mark Neal.]

18z GFS. Good portion of country seeing snow, apart from SW. Monday into Tuesday, similar to what some of the ECM were showing.

Edited December 4, 2017 by Mark N

[Snowmadsam]

Please can we bear in mind posting Precip charts is as likely as playing pin the tail on the donkey in regard to slider lows at the moment. These are very much now-casting events. You may have more chance of winning the lottery than taking them seriously

[blizzard81]

3 minutes ago, Man With Beard said:

D12 looks interesting

It does indeed. Cluster 1 looks amazing! 

[Mark Neal.]

1 minute ago, Snowmadsam said:

Please can we bear in mind posting Precip charts is as likely as playing pin the tail on the donkey in regard to slider lows at the moment. These are very much now-casting events. You may have more chance of winning the lottery than taking them seriously

Thats very true, but no harm in posting the output which the models are showing, though ofcourse will change, and quite a bit too from run to run! pinch of salt and all that. 

[blizzard81]

Wow! 18z goes ugly in the end. Hope it is an outlier. That pv to our north west that has haunted our dreams for the last few years is really beginning to worry me though, it has to be said. 

[bluearmy]

Day 15 cluster shows 2/3 probability of those growing heights to our ne 

[Smiler1709]

GFS 18z havin none of a Scandi high in the latter stages. Hopefully it sorts itself it tomorrow otherwise are be having a right old word with it. 

[andymusic]

Just now, blizzard81 said:

Wow! 18z goes ugly in the end. Hope it is an outlier. That pv to our north west that has haunted our dreams for the last few years is really beginning to worry me though, it has to be said. 

don't panic - just another far in the distance gfs run - it'll be different again out in the far distance of time tomorrow - hopefully wiith more of those scrummy easterly charts - you never know - concentrate on this weekend coming and just after for the snow fun

[Methuselah]

Just now, Smiler1709 said:

GFS 18z havin none of a Scandi high in the latter stages. Hopefully it sorts itself it tomorrow otherwise are be having a right old word with it. 

Indeed not...It's expired. It's dead. It's ceased to be...?

[blizzard81]

1 minute ago, bluearmy said:

Day 15 cluster shows 2/3 probability of those growing heights to our ne 

66% is very good at that range. Too far out to get too carried away just yet though. 

[Frosty.]

Wouldn't this be lovely..please 18z make it so..I mean snow!

[BLAST FROM THE PAST]

53 minutes ago, karlos1983 said:

This could well be a dry slider!!

Oh no!  Not a Dryder!! 

 

BFTP

[ArHu3]

2 minutes ago, blizzard81 said:

Wow! 18z goes ugly in the end. Hope it is an outlier. That pv to our north west that has haunted our dreams for the last few years is really beginning to worry me though, it has to be said. 

I just booked wintersports for the last week of this year, go figure a euro high with a föhn should pop up