Jump to content
Holidays
Local
Radar
Snow?
Paul

Model output discussion - mid January

Paul

Before posting in to the model discussion, please read our guide to posting in the model threads.

Message added by Paul

Recommended Posts

I think the lack of excitement for the ECM is because it has very little support from other models. I can only find the JMA that looks similar, along with some ensembles from other models. Until we see some support from UKMO / GFS / GEM I wouldn’t get your hopes up. 

Share this post


Link to post
Share on other sites
1 hour ago, Summer Sun said:

No UKMO extended this morning I'm afraid it should return once the federal government shutdown end's

I think also due to a fire at the MetOffice IT building overnight as we are missing the whole run and a lot of features missing on their site. 

Share this post


Link to post
Share on other sites

Looking forward to seeing any cold potential. I remember on several occasions IF mentioning cold several weeks out on previous occasions and getting it spot on. So when he says it then I take note . Pathetic F1 gfs charts just a waste of time . Gfs cold charts with 3-4 day time frame then gets my attention but even they can change even in that short time frame.  So maybe hope for some more cold for Feb on the way.............. 

Share this post


Link to post
Share on other sites
16 minutes ago, bradythemole said:

I think also due to a fire at the MetOffice IT building overnight as we are missing the whole run and a lot of features missing on their site. 

Beat me to it!

http://www.plymouthherald.co.uk/news/fire-shuts-down-met-offices-1103803

The
actual supercomputer isn't damaged thankfully. Hopefully forecasts will be back up again soon.

Share this post


Link to post
Share on other sites
1 hour ago, Summer Sun said:

No UKMO extended this morning I'm afraid it should return once the federal government shutdown end's

What does the US government shut down have to do with the UKMO? Am I missing something?

As has been said, they're having severe issues due to the fire. The UKMO and UKV are mainly affected, Euro4 is okay by the looks of it. Thankfully most of my gritting forecasts today are as mild as mild can be...

Edited by Nick L

Share this post


Link to post
Share on other sites

Ooh could you imagine the meltdown if we didn't get a UKMO output for a week or so.:wallbash::wallbash::bomb:

Share this post


Link to post
Share on other sites

gfsgwo_1.png

GEFS sure is going for it now - but only relative to the model with it's low AAM bias. Still not projecting a more useful GWO P5 movement but P4 does suggest the MJO is making itself felt for the time being at least. Oddly the 'day zero' starred point keeps on locating in 4 only for the actual observation to be still in phase 3, albeit crawling toward 4.

I've not often seen such a slow movement in 3 which I imagine is testament to the battle going on between the Nina and MJO forcing; there's a mighty tug of war going on now.

GFS and ECM both toying around with some degree of amplification but in different places. How very helpful :p

Share this post


Link to post
Share on other sites
4 minutes ago, Chris101 said:

Ooh could you imagine the meltdown if we didn't get a UKMO output for a week or so.:wallbash::wallbash::bomb:

We'd actually have to look out the window for a more reliable forecast? :D

Share this post


Link to post
Share on other sites

Quite striking the differences between the 00z EC and GFS ops in the 8-10 day range, particularly over Europe, EC has a deep trough whilst GFS has an Azores ridge extension into W Europe:

ecgfs_00z.thumb.png.e4a96d89ac351e7c604f700ccc6353f2.png

00z GFS looks slightly out of kilter with the 00z GEFS H500 mean day 9, the op with the ridge further east over Europe

gfs_z500a_nh_37.thumb.png.f41a524a6bf22cc4433b435fab0aabe4.pngGFSgefs_z500a_nh_37.thumb.png.a3f74e604ee0b6237c9688c1e131cde7.pngGEFS

00z EPS H500 mean more substantial troughing over western Europe

eps_z500a_nh_37.thumb.png.08f3c67ddc0f83105944e27cc9e94472.png

Wondering whether the big anticyclonic wave breaking / ridging over far N Pacific around Bering Strait and into the arctic is creating some issues and uncertainty in the models resolving the upper pattern and energy distribution downstream over N America and then Atlantic.

Share this post


Link to post
Share on other sites

Morning all :)

A chance for me to take a look at the morning's medium term output to see where the early days of Febraury might find us.

So, it's the charts for T+240 which means Friday February 2nd so starting for a change with ECM:

ECM1-240.GIF?23-12

A dramatic opening shot from the European model. A cold NE'ly though not remarkably so (850s between -4 and -8) and likely to be unsettled particularly to the south and east with rain or snow but fine to the far north west. Basically, the Azores HP tilts toward Greenland allowing a small but complex LP to move down from the NW into Europe. Have to say this looks a classic toppler.

GEM 00Z OP at the same time:

gem-0-240.png?00

Very different. A much flatter pattern with less amplification. The Azores HP is ridging into Europe rather than to the north so much milder and drier conditions for the south while the north remains unsettled under a more Atlantic dominance.

GFS 00Z OP at the same time:

gfs-0-240.png?0?0

Different again. The Azores HP has moved much closer to the British isles and while there is a cool NW'ly breeze down the east coast, for most it would be dry and settled albeit with frost at night under clear skies. Further into FI and strong Azores HP cells (1045 MB and above) do battle with a powerful jet firing deep LP out of eastern Canada. Unsettled and often very windy or stormy but mild in the south. Colder in the north with snow to altitude likely.

GFS 00Z Control at the same time:

gens-0-1-240.png

The Control has the HP in charge and sat right over the British Isles but its evolution isn't dissimilar to the OP in terms of the struggle between the HP cells and the jet stream.

Looking at the GEFS at T+240:

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240

The main theme here is anticyclonic. Many members have HP close to or over the BritIsh Isles, two or three get the HP further north or NE to advect some colder air over the British Isles but it's MLB day to this observer so little for snow fans but for fans of cold always the hope of some inversion leading to frosty and foggy conditions.

MY take on the morning's mid range output is we have a very wide range of evolutions but all are dependent on the behaviour of the HP cells which form over the Midwest and head SE into the Atlantic and basically re-enforce the Azores HP cell. ECM offers a tantalising vision for cold.snow fans but I'm far from convinced. GEM plays the flat game and could be right but the signal for HP dominance at this time of year is often right - February is a dry month - so GFS looks the form horse but whether the HP can get far enough north in the face of a strong jet is still open to question. MLB looks more likely than HLB to this observer at this timer but fans of cold know the HP doesn't have to be too far north to draw in a colder continental flow.

Share this post


Link to post
Share on other sites

The GFS 06Z OP is, if anything, even more anticyclonic in FI. Barometer-breakingly high pressure more or less over the British Isles but some interesting charts and things to note on the periphery:

T+240:

gfs-0-240.png?6

It doesn't happen this time but it's an indication that a Scandinavian HP isn't off the table.

Here's T+336:

gfs-0-336.png?6

The thing to note here is the LP which moves out of Africa toward Greece. This brings some wretched weather for SE Europe but helps "hold up" HP further NW. If we want MLB as far north as possible we need this storm or something similar to lower heights in the Mediterranean basin.

 

Share this post


Link to post
Share on other sites
1 hour ago, Nick L said:

What does the US government shut down have to do with the UKMO? Am I missing something?

As has been said, they're having severe issues due to the fire. The UKMO and UKV are mainly affected, Euro4 is okay by the looks of it. Thankfully most of my gritting forecasts today are as mild as mild can be...

 

The site I use is down is due to the US government shut down though It wouldn't make much difference with the fire which I wasn't aware of earlier this morning

http://ruc.noaa.gov/hfip/tcgen/

 

 

Edited by Summer Sun

Share this post


Link to post
Share on other sites
6 minutes ago, Summer Sun said:

The site I use is down is due to the US government shut down though It wouldn't make much difference with the fire which I wasn't aware of earlier this morning

http://ruc.noaa.gov/hfip/tcgen/

 

 

With a congress passed deal, NOAA should be up again later today :)

Share this post


Link to post
Share on other sites

Why is it that it seems whenever we have a chance of HLB delivering cold to UK, it seems we get a ridge & trough over N America bringing cold there and firing up the jet stream. I suppose maybe it because when there is a negative AO, the high pressure can spread there as well as here. Anyway I think hopefully this winter is a transition period between cold going to US fading, and going to Europe instead, just a 'funny feeling'.

Share this post


Link to post
Share on other sites

The trend continues high pressure to east north east colder weather  in the south of Britain with easterly flow..

IMG_0451.PNG

IMG_0452.PNG

Edited by abbie123

Share this post


Link to post
Share on other sites

Run P17 from the GFS 06 is pretty nippy and snowy...... But these runs are in the minority but a consistent minority.

Share this post


Link to post
Share on other sites

Yes, Abbie, I can see why this image might be a cause for excitement: IMG_0451.thumb.PNG.c289ac739116671399258

That said, it is, just a tad, away in Neverneverland, Narnia, or even away where the faeries live!:D:santa-emoji: 

Share this post


Link to post
Share on other sites

Nothing really in the output for coldies to get there teeth into. Any potential is in the far reaches of fi but on the bright side only 54 days till spring. Where we will start the chase of Spanish plumes :rofl::rofl:

Share this post


Link to post
Share on other sites

On the contrary, lots of small carrots on the ECM clusters once again. As I said yesterday, hopefully it is going redeem itself after last week's medium-sized fail at NE heights!!

T84 is an example of how a chart with a slight Euro trough anomaly might look good for cold but actually isn't at all without ridging getting further north:

ec-ens_nat_z500scenarios_2018012300_084.

The ensembles stay pretty tight until T168, where the main cluster begins to dig the trough into the Atlantic a little

ec-ens_nat_z500scenarios_2018012300_168.

resulting in a reasonably attractive T240 chart from cluster 1, with a weak ridge to our north and small trough to the south. Should equal something continental!

ec-ens_nat_z500scenarios_2018012300_240.

Various attempts at ridging between D11-D15 but largely flat in the Atlantic again by the end of the period, still can't get those Euro heights up...

ec-ens_nat_z500scenarios_2018012300_360.

Share this post


Link to post
Share on other sites

Still quite a few differences upstream between the latest GFS 06hrs run aswell as the earlier 00hrs and the ECM and this centres around two areas.

Firstly this discussed in the New York state forecast:

There are some rather significant model
differences for Sunday into Monday....as the 00z GFS brings the
cold front through the area much faster, with strong CAA
arriving during the day on Sunday. Meanwhile, the 00z ECMWF, 00z
CMC and several of the 00z GEFS (Ensemble members) favored a
wave traveling from the Gulf of Mexico north-northeast along the
stalled frontal boundary in the Sunday-Monday time frame. This
scenario would bring a period of steady rainfall to much of the
area...eventually and gradually changing to wet snow from NW to
SE during the day Monday. For now, took a blend of the latest
available guidance but weighted the ECMWF/CMC scenario a little
higher, as the GFS seems to be an outlier at this time.

That wave eventually develops into a more amplified low which runs ne up the eastern seaboard. This downstream helps to pull the high further west and north to meet up with the ridge ahead of that upstream low.

Given todays VP 200 forecast and current state of the MJO and the increase in amplitude of the signal shown in the forecast which screens out interference then I think more amplified upstream going forward rather than less would be  a better bet at this time.

Interestingly if you look at the normal RMM forecasts and current state they seem to place the MJO further west than the VP200 with ENSO.

So perhaps this is muddying the waters but either way currently the MJO is still maintaining decent amplitude.

 

Share this post


Link to post
Share on other sites
4 hours ago, Chris101 said:

Ooh could you imagine the meltdown if we didn't get a UKMO output for a week or so.:wallbash::wallbash::bomb:

Ha! They're booting Hall 1 up (fire was in Hall 2) so feeds should hopefully be back online by this evening, tomorrow morning at the very latest :)

Share this post


Link to post
Share on other sites
2 hours ago, Bruegelian said:

Why is it that it seems whenever we have a chance of HLB delivering cold to UK, it seems we get a ridge & trough over N America bringing cold there and firing up the jet stream. I suppose maybe it because when there is a negative AO, the high pressure can spread there as well as here. Anyway I think hopefully this winter is a transition period between cold going to US fading, and going to Europe instead, just a 'funny feeling'.

I feel that many do called signs favoring a cold NH, like snow cover and snow advance, low sea ice, warm arctic  actually work against us. We need to look for warm us east coast, cold west coast / Alaska signs (if they are known) 

Share this post


Link to post
Share on other sites

Latest MJO forecasts now updated .

An increase in speed of the signal . The ECM has this into phase 6 by day 7. Into phase 7 by day 11.

The GEFS is slower once into that phase to take into phase 7 with it creeping along much slower but NOAA normally factor in the ECM more because of better verification .

Edited by nick sussex

Share this post


Link to post
Share on other sites
3 minutes ago, nick sussex said:

Latest MJO forecasts now updated .

An increase in speed of the signal . The ECM has this into phase 6 by day 7. Into phase 7 by day 11.

The GEFS is slower once into that phase to take into phase 7 with it creeping along much slower but NOAA normally factor in the ECM more because of better verification .

What's the amplification signal like though Nick? Near the CoD or more amplified?

Share this post


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

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...