Model output discussion - into 2018

[High Altitude]

2 hours ago, BLAST FROM THE PAST said:

Easterly, SE’ly, NW’ly will it won’t it....next run is crucial, winter is over until next decade, you were wrong, you are the bleaker.......guys and girls it matters little who calls what..have your view and let it evolve and move on....not getting Synoptics spot on isn’t failing.

10 hours ago I left Swansea to come home for a day to see my wife and son.  Been in Swansea as my dad was poorly and been in hospital since before Xmas.  I thought when I kissed him fairwell that I would be back to see him on Thursday.  He passed away 2 hours ago...and I’m 200 miles away.......now THAT is failing......

I will be gone for a while...

 

BFTP

I don’t post in here often but even so I check in here religiously and have done so for over 15 years now and so in my own way I feel a connection with the community. On that note I just want to send my condolences to BFTP. My thoughts are with you at this trying time....and you didn’t fail anyone! When you’re ready I along with many others I’m sure will welcome return. 

[Cheshire Freeze]

Even modest elevations towards the NW of the UK are absolutely pasted on this run

Snow totals on hills could be quite significant if the above came to pass.

[snowstorm27x]

22 minutes ago, CreweCold said:

Even modest elevations towards the NW of the UK are absolutely pasted on this run

Snow totals on hills could be quite significant if the above came to pass.

Yep i would say the Midlands Northwards it's almost identical to what the Midlands was plastered with in December. That is some cold air coming from the west also minor adjustments will hopefully put the rest of the UK in the game. But this looks a very snowy run I would like to be in the Peak district if this came off as modelled. Do you think the block would stall the front and if so will it help or hinder the upper temps.

Edited January 10, 2018 by snowstorm27x

[Cheshire Freeze]

5 minutes ago, snowstorm27x said:

Yep i would say the Midlands Northwards it's almost identical to what the Midlands was plastered with in December. That is some cold air coming from the west also minor adjustments will hopefully put the rest of the UK in the game. But this looks a very snowy run I would like to be in the Peak district if this came off as modelled. Do you think the block would stall the front and if so will it help or hinder the upper temps.

Well, the less time the air mass spends over the sea, the less modification of the uppers will occur. With this in mind we wouldn't want to see the low pressure held up for too long. 

That being said, the block is enabling the jet to angle nw-se and thus the LP to elongate- this means that there is less modification from TM air entering the circulation than you would usually see with a low pressure system. 

It's a very very interesting set up, and that's without taking into account disturbances in the flow that could deliver to wider areas. 

[snowstorm27x]

Cheers for the heads up. So a middle ground solution is no good as it would mix out the colder air.

[Banbury]

29 minutes ago, snowstorm27x said:

Yep i would say the Midlands Northwards it's almost identical to what the Midlands was plastered with in December. That is some cold air coming from the west also minor adjustments will hopefully put the rest of the UK in the game. But this looks a very snowy run I would like to be in the Peak district if this came off as modelled. Do you think the block would stall the front and if so will it help or hinder the upper temps.

Depends where you call the Midlands , we had 20cm in December, 

[BlueHedgehog074]

Just an example at 204 hours, the 00Z GEM manages to clear the Atlantic trough approaching from the West next week East into mainland Europe pulling in a chilly Northerly/North-Easterly flow over the U.K. Probably some heavy wintry showers in places!

(Worth saying that the GEM tends to under-estimate the coldness of the 850 hPa temperatures - would expect those upper temperatures to be at least a degree or two colder)

GFS 00Z concentrating the Atlantic trough more to the North of the British Isles around the same time frame, hence more of a Polar Maritime North-Westerly feed over the U.K. Either way, both scenarios do look chilly overall. 

Looking at both the GFS and GEM runs at 144 hours, and you can see they both show differences to the orientation and shape of the Atlantic Low/Trough:

GEM 00Z

GFS 00Z

The GFS shows more of a ball-shaped Atlantic Low. It’s a little less squashed and not as negatively tilted compared to that of the GEM run. The blocking to the North-East over Scandinavia exerts less influence on the Atlantic trough on the GFS, whereas more pressure seems to be exerted on the Atlantic trough from the Scandinavian blocking on the GEM run. More in the way of ridging over Northern Greenland too which I think helps! Plus, upstream towards Eastern Northern America, the pattern seems a little more amplified on the GEM 00Z at 144 hours.

I think these aspects seem to be some of the things that help disrupt and force the Atlantic trough South-East into mainland Europe on that GEM run more quickly and easily than on the GFS 00Z run. 

Maybe some things to look out for on future runs (just my opinion away, but I admit I’m not an expert on this kind of stuff)  

Edited January 10, 2018 by DiagonalRedLine

[northwestsnow]

Nice GFS / GEFS-

UKMO no as nice at 144 imho....

[carinthian]

latest runs still have no break through. The block seems even more resistant this morning. Each attempt by the Atlantic  gets repelled as shown on the charts below. Note how the increasingly powerful 300mb jet again splits west of the British Isles. That's indicative of a strong block in place. How long can it continue to hold the Atlantic trough pushing through ? According to the models by 120h. However, again, I have a feeling this could yet be put back by at least another 24 hours. The longer the block holds , the greater chance of further trough disruption that may lead to snow in the longer term charts ( 7 o 9 days time ) . I will get back with further thoughts from our experts later today for those who are interested.

C

[bluearmy]

7 hours ago, Purga said:

Just wait until everything corrects south BA

If the new ec op is sniffing a new evolution in removal of the polar high, we are heading north, not south with no mid Atlantic amp to draw the Azores ridge west, it will push its influence east into Europe somewhat = no euro troughing and general cool zonality for us maintained but with more wnw tha nnw and more big warm sectors. Not the direction of travel most envisaged. Anyway, many will hope that its just jumped to another cluster, temporarily. 

[northwestsnow]

EC shows what could be decent snow chances 144-168 this morning but goes quickly downhill thereafter ...

[Seasonality]

18 minutes ago, carinthian said:

latest runs still have no break through. The block seems even more resistant this morning. Each attempt by the Atlantic  gets repelled as shown on the charts below. Note how the increasingly powerful 300mb jet again splits west of the British Isles. That's indicative of a strong block in place. How long can it continue to hold the Atlantic trough pushing through ? According to the models by 120h. However, again, I have a feeling this could yet be put back by at least another 24 hours. The longer the block holds , the greater chance of further trough disruption that may lead to snow in the longer term charts ( 7 o 9 days time ) . I will get back with further thoughts from our experts later today for those who are interested.

C

Good post @carinthian 

Just to emphasise to everyone that he is using the ARPEGE there and in a situation like this where even the short range is so uncertain, use of the higher res short range models is very pertinent. *edit, have included t+96 on ECM, GFS and ARPEGE for comparative purposes. The high seems sturdiest on ARPEGE, with such variation even the weekend remains uncertain.

Edited January 10, 2018 by Seasonality

[snowbunting]

This just gets more intriguing every morning. Looks like NWly flow will prevail.. bringing a cooling trend for by day 7 to 10. Snow defo possible yo NW and higher ground western parts start of next week. However, afterthat it looks like a bit of a battle between east v west... it really depends on how far the scandi block manages to progress westwards. Could be significant snowfall events for those further South as that colder air hits atlantic fronts. Also watching that SSW event on Fl as this could change everything. 

 

[TEITS]

Thankfully UKMO heading towards GEM output this morning.

A big headache for the models coming up with regards to the trough and how much energy heads SE.

[alexisj9]

5 hours ago, ukpaul said:

On some ensemble members maybe still but, once those lower uppers coming from the west have gone, i think they aren’t coming back. The sterile cold shown from the east is okay if you just want dry cold but I don’t think people are looking for that.

Should have mentioned, I only looked up to 240h in the high res, not FI.

Me too I meant the cold is building in the east, it will be cold.

[winterof79]

Ahhh the phantom warming doing a Mr Ben.

 

[Frosty.]

Plenty of cold zonal unsettled weather next week with wintry ppn, frosts and ice..some parts would get a good dump of snow, especially with some elevation..looks far more interesting next week than this week!! 

[Chesil View]

Very much standard winter fare this morning on the models medium term No blow torch I'll grant you ,but typical westerly/ northwesterly airstream stuff really, yes there could be some snow for those at elevation midlands northwards but thats always the case in non blowtorch conditions anyway. certainly nothing unusual. Lets hope that GP's and Catacols musings about hieght rises to thr north later in the month show some promise otherwise its going to be a long winter searching for some meaninful snow fall down here in south Dorset.

[January Snowstorm]

The coldest uppers are getting watered down a bit next week. Looks more like transient sleet/snow now with a lot of cold rain. As others have mentioned it's typical winter fare for mid January 

[supernova]

Pretty uninspiring stuff this morning with GFS ensembles predicting a general cooling trend but nothimg to stir the soul. Not much scatter either for the next week.

[mb018538]

4 minutes ago, supernova said:

Pretty uninspiring stuff this morning with GFS ensembles predicting a general cooling trend but nothimg to stir the soul. Not much scatter either for the next week.

Yep, just bog standard unsettled chilly winter weather. More along folks, nothing to see here!

[Frosty.]

Ecm 00z looks quite wintry next week, especially further north and I'm sure there would be significant amounts of snow further north with a strong blast of cold zonality..

[frosty ground]

8 minutes ago, Frosty. said:

Ecm 00z looks quite wintry next week, especially further north and I'm sure there would be significant amounts of snow further north with a strong blast of cold zonality..

The ECM for the last two runs haven't been that good, The day 5 Chart is showing a temporarily South Westerlies and the Cold Zonality is still out at day 6.

[nick sussex]

After last nights excitement its a bit of a hangover this morning.

From early doors the GFS was never going to repeat last nights runs with too much energy east less going se'wards.

It's not like we're dealing with a rampant PV stuck to the north , it looks pretty disorganised but theres a lack of amplification upstream to drive lower heights further se.

The ECM is even more progressive this morning. The 850's look on the cool side so some snow for the north with elevation. Perhaps  a shortwave might develop and run east at the base of the trough which might spring a surprise.

It's not a horror show by any means but we really don't want to see any more flattening.

The UKMO looks a bit more amplified but the overall pattern is similar.

[Summer Sun]

UKMO extended remains with a northwesterly flow