Model Output Discussion 01/09/17

[northwestsnow]

Poor ECM, blocking never gets hold like gfs and it looks fairly flat at the end.

Lesons to be learned for winter.

[Daniel*]

1 minute ago, Ed Stone said:

Because, in the good-old-days, soil temps and SSTs were much lower in February than they were in November...ergo, in November, rain/sleet off the North Sea - and any snow that did manage to fall usually melted on contact with the ground...

And - these days??!!

You’re not wrong. Well soil temps are much too high currently for settling snow away from northern uplands IMO a cool down between 1-2 weeks of anticyclonic weather with frost - preceding the main blast of cold air would be needed. I was just addressing Surrey dismissing the chance of snow in the south. It’s not quite too early but indeed earlier than we would preferably like. 

[Methuselah]

1 minute ago, northwestsnow said:

Poor ECM, blocking never gets hold like gfs and it looks fairly flat at the end.

Lesons to be learned for winter.

Bugger! The first lump of 'potential' flushed down the toilet...Never mind peeps, winter is still FIVE WEEKS away!

[NeilN]

If anything I want seasonal temps, and I take it this is what the models are showing. I'd like snow, but it's a bit early especially for us in the South West. January would be ideal. 

[lassie23]

We really need models to agree before we can get excited, which they rarely do these days

[northwestsnow]

met office going for a cold northerly with snow for parts of scotland so im disounting ecm tonight.

[Allseasons-Si]

30 minutes ago, northwestsnow said:

Poor ECM, blocking never gets hold like gfs and it looks fairly flat at the end.

Lesons to be learned for winter.

But there could be upgrades

 

 

 

[damianslaw]

Gosh this thread has suddenly come into life, and why, because the charts are showing colder synoptics on offer, (must be lots of cold lovers out there..). As always its not worth getting hung up on charts beyond the 168hr timeframe, they rarely verify as shown at such range, or should I say, margin for correction is high. Always best to look at the general developments taking place for an idea of the overall theme and trend in the mid range.

All models are consistent in showing mid atlantic ridge strengthening and pushing north, with the jet aligned on a NW-SE axis, hence a propensity for the trough to anchor down from the NW by the end of the week, introducing much cooler air, and cleaner air - hooray for the latter, sunshine should show its face again, and perhaps the first white sprinkle for the high tops by early next week.

Whether we see a direct long fetch northerly, a northerly toppler, is all conjecture. GFS is showing a potent northerly, ECM less keen but does bring one in eventually, but not as potent. W

 

 

[ANYWEATHER]

Hello Folks , Fancy sitting in the Rollercoaster chair Ecm shows a colder weekend , gfs shows a milder weekend , gfs shows unseasonably cold weather in its later frames , ecm shows something a lot tamer....Gts shows a really goolish  Halloween . becoming very cold , perhaps snow for some ,really makes a change from recent years;;; Follow the witch....

[Allseasons-Si]

And hot on the heels is the latest 8-14 day 500mb outlook from NOAA sticking with it's guns as it did last night,just a wee bit of an upgrade in terms of heights in the Atlantic pushing into Greenland but tonight's shows more height's in that vicinity and into Svalbald and polar region's too with the trough still in Scandinavia,Atlantic still blocked

here is the 850 hpa temps for London,as you can see by the turn of the month there is quiet a few membes going for -5 at the start of the new month,we just need the mean to get there now

average temps

Edited October 23, 2017 by Allseasons-si

[knocker]

The anomalies this evening would appear to be a god example of how small adjustments to the upper air pattern result in in different interpretations by the det. runs and weather impacts on the UK in the medium term. And the key to a large extent would appear to be the often forgotten cut off upper low in the Atlantic.

With the GEFs it plays a far more active role that promotes greater amplification which veers the upper flow NW and portends troughs digging SE very near the UK with the possibility of transient northerlies. The ecm on the other hand has it far less active and the pattern far less amplified and thus the upper flow trending more westerly. NOAA perhaps more inclined to the GEFS.

So until this is sorted disagreements will continue vis the detail. What does appear to be the percentage play for a few days is for the upper flow to be north of westerly, temps trending below average a little which always leaves the door open for some transient northerlies

 

 

 

Edited October 23, 2017 by knocker

[knocker]

I should have added to the above that the ecm also has a more active vortex lobe over Franz Joseph which effects the orientation of the Scandinavian trough

Edited October 23, 2017 by knocker

[karlos1983]

I will not allow myself to get excited about GFS charts showing a northerly arctic blast, especially so far out and without interest from the Euros. It’s only October, model fatigue could set in before winter starts lol 

Guess it will be interesting to see if that ecm was a mild outlier when the ens get published.

[cheshire snow]

Purely for fun at this range,but GFS 18z showing Snow showers for the higher parts of Scotland,NI,and Wales to start the new Month,showers perhaps even wintry to low levels Midlands north

C.S

[Man With Beard]

1 hour ago, karlos1983 said:

I will not allow myself to get excited about GFS charts showing a northerly arctic blast, especially so far out and without interest from the Euros. It’s only October, model fatigue could set in before winter starts lol 

Guess it will be interesting to see if that ecm was a mild outlier when the ens get published.

Similar to this morning. ECM ensemble clusters at D8-D10 fairly split over the influence of the Scandi trough and Atlantic high. There is a cluster similar to the GFS, but it's smaller than the op/control cluster, and there's also a cluster that is potentially milder than the op run still. What does that tell us? Not much

[JBMWeatherForever]

I said on Saturday that things seemed increasingly good for early November as the signals were just to strong to ignore, and I see the models continuing to play with what looks to me like a decent spell of early cold weather. Many on here seem to still be dismissing it, and yet the models keep showing it, time and time again. I think November is going to be quite a shock to the system, especially after such warm temperatures this week.   

[knocker]

The general picture of cloudy, wet and temps above average continues today, albeit with regional variations. the south and east the more likely to get peeks of sunshine and stat dry, whilst the west, north west could be quite wet particularly the latter, N. Ireland and Scotland initially quite wet but should clear to blustery showers. Once the rain has cleared tomorrow should be a better day apart fro N. Scotland that will receive some rain from a depression tracking NE in the proximity.

.

So, according to this morning's gfs, by Thursday the UK is in a slack HP area and the pattern is emerging which by now is familiar to us all. As can be seen at 12 we have the faithful cut off upper low to the south west flanked by strong high pressure that is surging NE around the low. Thus the UK becalmed with temps ranging from 9C-16C latitudinally. Over the next couple of days this pattern continues to evolve with the high cell becoming established to the west of the UK and enery,troughs tracking east around the top before dipping south east into eastern Europe. So the UK remaining dry, except perhaps once again N. Scotland with temps returning to around average.

.From this point the gfs takes a different route to yesterday. As the ridge moves east over the UK the next trough tracking east from the NW joins forces with our cut off low and by Tuesday 00 a trough is approaching from the west  Twenty four hours later the low has deepened to 960mb and is between Iceland and Scotland bringing gales to the latter whilst the associated fronts track SE across the UK bring rain to all followed by showers in a blustery north westerly. At this point it is interesting to note the much colder airmass behind.

From this point the low fills and tracks into southern Norway and with the wind veering N. the UK comes under the influence of the colder air with snow quite possible in Scotland. But looking at detail at this range is a no no but just to reiterate this scenario is much in keeping with the overall picture from the anomalies, albeit the EPS not quite on board, as can be seen by this morning's GEFS

Edited October 24, 2017 by knocker

[Summer Sun]

Has ECM gone down? I only have yesterday's 12z

[knocker]

11 minutes ago, Summer Sun said:

Has ECM gone down? I only have yesterday's 12z

It must have done it doesn't appear on any site I've looked at although I haven't seen any reason given

[Snowy Hibbo]

So the EC Monthly run, Monday edition, has been released (only released on a Monday and Thursday). I posted information about the long range climate drivers two pages ago. Now I am going to have a look at the most reliable (out of a pretty poor bunch) long range model there is.

 

This week's 500mb anomalies. You can see a fairly strong ridge to the SW, which sets up the jetstream to come across the U.K. and head southeast across Continental Europe. Then it makes way for troughing in Eastern Europe into Russia (which also happens to help Eurasian Snow Cover expansion, which is a important factor in winter).

 

Week 2 (Next Week) 500mb anomalies. Again a ridge exists near the UK, probably to the west. The UK is on the Eastern edge of this ridge. The trough over Eastern Europe strengthens and moves west, potentially dumping snow across Eastern Europe and the European Alps. EC46 Precipitation anomalies show drier than normal conditions for most of the UK, except North Scotland. The snow anomalies show somewhat higher than normal snowfall in parts of the Scottish Highlands, particularly to the far north. The temperature outlook is mostly neutral for this period.

Week 3 (Week after next week) 500mb anomalies. A ridge is over the Atlantic, near the UK, with the UK being on the ridge's northern boundary. Snow anomalies are neutral, same for temperature anomalies. Precipitation anomalies are wetter than normal in Northern Scotland, but drier than normal for rest of the UK.

Week 4 Ridging anomalies for Southern UK regions. The jetstream seems more going towards the ENE across the U.K, than the other earlier weeks (which were going more to the ESE) IMO. Precipitation anomalies show a wet UK, with most of the region under wetter than normal anomalies. Temperature and Snowfall anomalies are mostly neutral.

That is the EC Weekly model update. Hope you enjoyed that. All detail is IMO.

[Snowy Hibbo]

13 minutes ago, knocker said:

It must have done it doesn't appear on any site I've looked at although I haven't seen any reason given

Yeah mine is down too. Weird....

[ICE COLD]

25 minutes ago, Summer Sun said:

Has ECM gone down? I only have yesterday's 12z

It's because on this mornings run it shows -10 850s over the uk with major blizzards on days 6,7,8,9 and 10 . 

[snowbunting]

This potential Nly outbreak in early Nov is nothing out of the normal. We used to have these cold snaps mid autumn time alot in the 80s and 90s. Indeed it would be interesting to see the similarities in the synoptics between now and autumn  ( mid oct ish) 1998 and  ( nov 1st) 2001.  Where we had several nly outbreaks filter down in the north of scotland. 

 

[booferking]

First model battle of winter goes to GFS via knockout first round ECM not seen are talked to the media since last night.

[blizzard81]

Strange that no reason has been given for the ecm no show. Has the model had enough already lol.