Jump to content
Sign in to follow this  
phil nw.

Model Output Discussions 18z 31/01/2016

Recommended Posts

3 minutes ago, northwestsnow said:

Not sure the euro models look all that wintry either frosty, maybe ecm at day 9 and 10 but we know from bitter experience they hardly ever verify.

The Ecm 00z shows widespread 520 dam thicknesses at day 10  which I would love to see verify before this feeble excuse for a winter is over!:)

240_mslp850uk.png

240_thickuk.png

ecmt850.240.png

Share this post


Link to post
Share on other sites

The GEFS anomalies have a much weaker Atlantic ridge with low heights not digging that far south. By D10 the UK is back to the north-westerly/westerly regime.

There is one bit of hope in that in the much later stages of the GEFS, pressure builds off the east coast unfortunately this is met with rising pressure to the south.

gensnh-21-5-372.png

 

Edited by SN0WM4N

Share this post


Link to post
Share on other sites

Better make the most of todays drizzle before the intense stuff heads back in at the weekend!!!

6Z Looks very wet for the weekend with atlantic depressions swinging in.

Share this post


Link to post
Share on other sites

Well another day another set of poor output the gfs looks wet and windy especially further south into the weekend and into next week. The ecm shows promise but once again it's day 9/10 days away. Think after the update yesterday in the strat thread from Ian ferguson my hope for this winter are over. Think now I would like to see some settled weather in the output just to give us a break from the Atlantic onslaught. 

Share this post


Link to post
Share on other sites
10 minutes ago, Tim Brawn said:

Why do the mods predict what isnt going to happen with 100% success rate , 

Because I think people are forced to look too far into the future on the model predictions. We all know that past 144hr is unlikely to verify so when we anticipate a change to our preferred weather type at day 9 or 10 we are setting out selves up for a fall. A mild south westerly flow is the norm in the UK remember that when looking at models and if it is showing deep cold treat the outcome with suspicion until there is model consensus within T144 or you see the snow falling in the light of a lamppost near you. Otherwise like me you will Keep .. :wallbash:

Edited by EastAnglian

Share this post


Link to post
Share on other sites
41 minutes ago, PLANET THANET said:

why do all our hopes stay at 10days out ?

The Ecm happy ending is day 10 but the evolution starts much sooner, hey at least I'm trying to be positive and offer glimmers of hope for the dwindling number of coldies left on here but I'm obviously flogging a dead horse so I won't bother any more!:)

Share this post


Link to post
Share on other sites

gfsgwo_1.png

The AAM is creeping slowly but surely upward in the GFS projections. As trends continue and the rise through 5/6/7 increases, expect to see more amplification in the 7-14 day period (allowing for time taken for this to propagate to the Atlantic; responses sooner Pacific/U.S.).

With such a complex picture mid-late next week, any detail on the consequences is out of reach, but there is the broad idea of there being a bigger window for height rises toward Greenland from the mid-Atlantic, and also increased propensity for trough disruption - which ECM has showed us in abundance this morning but with the jet stream not tracking quite far south enough for much of the UK to benefit.

The biggest consequence may well be on the attempted boosting of westerly momentum mid-month as the vortex looks to regroup in the Atlantic sector. I believe GloSea5 was exploring this opportunity up until yesterday and it may yet prove foolish for having dropped it all of a sudden. If a tropical feedback is mishandled it can impact an entire ensemble suite - just think of some of the wholesale swings in GEFS we've seen over the years.

Same message applies for the late-month MJO forcing. Indeed, what happens mid-month may well be linked to where we go late-month. It's all about those feedbacks in the Pacific :bomb:. Usual caveats apply of course, in particular the fact that the mid-month changes at least won't necessarily deliver for the UK, though I believe some transient snowfall is in with a good shout. It's about keeping the overall hemispheric pattern from locking into a nasty configuration.

I know we've had a lot of poor luck lately but what's the point of it all if we stop searching in hope for that elusive jackpot.

Edited by Singularity
Spoon.

Share this post


Link to post
Share on other sites

A few posts have been hidden, Please only use this thread for discussing the 'model outputs' there is a winter/moan thread for more general chat.

Thanks.

Share this post


Link to post
Share on other sites

Just checked the 00z GFS parallel to see if it was also faster with the low exiting the U.S. in 3 days time and yes, it was. Not only that but the outcome across the U.S. was as bad as I've seen for this event:

gfs-0-102.png?0

The run then turns into something of interest:

gfs-0-192.png?0 gfs-1-192.png?0

That low east of Iceland is a major part of that so it's rather circumstantial really. The trough disruption in the mid-Atlantic makes a more significant point to me.

The run continues to tease thereafter:

gfs-0-252.png?0 gfs-1-252.png?0

Very cheeky indeed, and most entertaining :clap:

It finally breaks down a couple of days later thanks - as usual - to a very large, deep trough firing out of the U.S. and across the Atlantic.

 

Still fascinated by that system in 3 days time though. The speed out of the U.S. makes the difference between outcomes such as the GFS parallel or the GEM 00z (below left) or indeed ECM 00z (below middle) and something like the UKMO 00z which holds the low back to our west as the pressure gradient peaks, sparing us the worst. A few of the high-res models have moved toward the UKMO outcome this morning so it has gained some credence.

gem-0-108.png?00 ECM1-96.GIF?04-12 UW96-21.GIF?04-06

 

This explains the lack of an advanced severe weather warning for strong winds on Monday from the Met Office.

Share this post


Link to post
Share on other sites

Is anyone else having a look at the GFS 6z ensembles? They look pretty nice to me- especially for 10-12th Feb where a lot of the runs show runners taking a more southerly track- dragging colder air from north into the UK. 

If there is going to be a surprise snow event anytime soon- its gunna be in this period. 

Oh yeah and this is day 6-8 not day 10. 

Edit: uppers are not particularly cold, but you never know....

Edited by BarnetBlizzard

Share this post


Link to post
Share on other sites

The ECM mean is not suggesting a 'mild' run coming up - progressively cooler / colder the further north and higher up one resides!

Reem1921.gifReem1922.gif

Reem2161.gifReem2162.gif

Reem2401.gifReem2402.gif

Nothing very 'wintry' though for most of us, the worst of both worlds coldish and damp - yuk...:closedeyes:

At least if it's got to be mild let's have it very mild springlike and pleasant please OR preferably at this time of year bitterly cold and snowy..:D

Share this post


Link to post
Share on other sites
8 minutes ago, BarnetBlizzard said:

Is anyone else having a look at the GFS 6z ensembles? They look pretty nice to me- especially for 10-12th Feb where a lot of the runs show runners taking a more southerly track- dragging colder air from north into the UK. 

If there is going to be a surprise snow event anytime soon- its gunna be in this period. 

Oh yeah and this is day 6-8 not day 10. 

Quite!

Potential for some snowfall pretty much anywhere in the UK. Often rather marginal but these situations can be very rewarding. Could be the most interesting period of winter to come :D

 

Edited by stainesbloke

Share this post


Link to post
Share on other sites

A look at a couple of day 5 GFS 06z images from this site

http://www.tropicaltidbits.com/analysis/models/

gfs_apcpn_global_20.thumb.png.8a2a475329gfs_z500_mslp_global_21.thumb.png.dfafef

 

to illustrate our dominant setup this season ie. the heat conveyor heading north east from the strong EN warmed tropical Pacific across the Gulf of Mexico and into the Atlantic.The moisture laden air heading across to the UK on the jet stream.Coupled with a very cold vortex and there we have the recipe for a mainly +veNAO/AO Winter pattern for the UK.

It looks like next week with the jet tracking further south does cool things off  somewhat as can be seen from the latest London ens.

ensemble-tt6-london.thumb.gif.69d9737b0a

Currently you would have to favour places further north and with some elevation more likely to see any more snowfall as the lows track across on a more southerly route.Of course we can never rule out a surprise event  as we get more polar air into the mix.

For many of us though, unfortunately, more wind and rain at times seems the main theme of the next 10 days.

Share this post


Link to post
Share on other sites

It does seem a case of one better output one worse every day with the ECM/GFS.

Todays ECM is improved but we're right to be a bit dubious of its longer range outputs, however the ECM day 10 is not bad at all because the PV is orientated more ne/sw and the troughing is digging more south.

The evolution from there could be interesting in terms of the UK but will the output survive to this evening?

The GFS after its dire 00hrs output improves on its 06hrs run but still has the PV much further east.

 

Share this post


Link to post
Share on other sites

GFS 06z ensembles clearly show a slightly less cold trend then recent days, the mean had been closer to the -5c for quite a few runs around the all important 9th-14th period but is now closer to the -2c. There remain colder members around that period though including the operational run which is certainly a positive.

 

Ensembles for London and Manchester:

Colder uppers and better snow chances up north, 11th-14th period looks best for Widespread UK snowfall.

graphe_ens3.php.gif

graphe_ens3-1.php.gif

Edited by snowray

Share this post


Link to post
Share on other sites

LOL GFS6Z had max's of 2 and 3 across North England next wednesday - the 12z has 10 and 11.

 

Share this post


Link to post
Share on other sites

What an astonishingly grim run the GFS has just produced in the next week or so. Yuck! Low after low with plenty of wind and rain.

Share this post


Link to post
Share on other sites

Indeed, whatever window we had for a potential cold snap moving into the reliable or even at day 10 has quite frankly gone up in a puff of smoke. Incredible how there has been a complete lack of consistency in the models.

Share this post


Link to post
Share on other sites

Yep the atlantic really is firing up  wind and rain barreling through the uk.  I always assumed the atlantic in Feb was supposed to be the least active.?

Share this post


Link to post
Share on other sites
2 minutes ago, weirpig said:

Yep the atlantic really is firing up  wind and rain barreling through the uk.  I always assumed the atlantic in Feb was supposed to be the least active.?

Me too - no sign of that happening on the evening runs, if anything it looks like the PV is INTENSIFYING over Greenland.

Share this post


Link to post
Share on other sites
11 minutes ago, weirpig said:

Yep the atlantic really is firing up  wind and rain barreling through the uk.  I always assumed the atlantic in Feb was supposed to be the least active.?

Feb used to always be a less Atlantic dominated month, it is very strange to see things so active and mild. I have no idea what is going on any more, no sign of any High Pressure in the next 10 days. This is just weird, and could lead to a very mild Feb and therefore mildest Winter on record.

Edited by snowray

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.
Sign in to follow this  

×
×
  • Create New...