Jump to content
Will it snow? 7 day forecast Weather Radar Will it be cold?
Snow?
Local
Radar
Cold?

nick sussex

Members
 View Profile  See their activity

  • Posts

    20,280

  • Joined

  • Last visited

  • Days Won

    150

 Content Type 

Everything posted by nick sussex

  1. nick sussex
    Yes I know sometimes the models can be too progressive and want to change too quickly but at this rate I'll be getting my heating allowance before they finally go for the change of pattern. Here the models actually suggested energy going se'wards into Europe within 168hrs, indeed the ECM has been bullish about this and even showed this yesterday within 144hrs, so if its not the case then its a big fail for the ECM operational output. I'll wait for tonight to see whether the ECM continues with its new flatter trend. You only get so many opportunities and if the models keep putting this back then inevitably it all ends in tears. As for the ECMs decent chart at 240hrs, that implodes if the models flatten the pattern out as they have recently,so overall regardless of what the medium term signals are we need to see this translated into concrete synoptics on the ground and not stuck at 240hrs for days on end.
  2. nick sussex
    A very disappointing ECM to start the day with the upstream pattern flattening out quickly and then its a case of waiting for another opportunity. This is quite a turnaround from the ECM which now doesn't even take any energy se'wards into Europe until well past 168hrs. The UKMO typically after being so lukewarm does take some energy se'wards, the GFS is not bad but messy but with some energy going se'wards. The GEM is very good in terms of colder potential but currently performing poorly in terms of verification so hardly one to have too much faith in. One wonders will any of these good synoptics make it into the reliable timeframe? Or will yet another variable appear like the jet flattening out once again. Overall after a few days of more positive trends the ECM in particular has ground to a halt, lets hope this operational is a one off and it reverts to a more amplified pattern this evening. It's all well and good seeing decent charts at 240hrs but we were at this point about 5 days ago. And five days later nothing of note has got within 144hrs!
  3. nick sussex
    I really would advise people to not worry too much about the lower resolution GFS output. The important thing is to get the trough disrupting and sending a shortwave se'wards, this is the main thing to worry about. This is all within 168hrs.
  4. nick sussex
    We're saved because the upstream pattern amplifies and that ridge to the west helps take some energy se'wards and that low then heads se but in all honesty the GFS makes a complete meal of things. Theres no way you'll get all those shallow lows just floating around ahead of the Atlantic low, the GFS has about 72hrs to eject a shortwave and yet somehow doesn't. All the drama should have been over well before the lower resolution output.
  5. nick sussex
    Any chance the GFS could split that trough and eject a shortwave before I'm old and grey! You can see the shortwave developing towards the nw of France around 138hrs and given the pressure rise to the ne this should force this shortwave to separate and head se but yet somehow the GFS can't bear to let go! ZZZZZ OMG just eject the damn thing for heavens sake! This is painful! You can see the model bias here the GFS is determined to keep the energy going north and not splitting it, if the model had a reality check it would have sent the shortwave se'wards by 144hrs and the high pressure would have then been allowed to ridge west.
  6. nick sussex
    Looking at the ECM ensemble maps it is a little difficult to judge what could occur post 168hrs as we don't get to see the upstream pattern but I'd say theres a good number of positive charts there, thankfully the underwhelming ones are in the minority, a couple of stinkers but with that many ensemble members you'd always expect to find a couple that have you reaching for the travel brochures to Lapland!
  7. nick sussex
    Some interesting comments regarding the upstream pattern from NOAA this evening: 12Z CYCLE...ALONG THE WEST COAST NO CHANGES WERE MADE TO THE PRELIMINARY PROGS. HOWEVER... THE 12Z GFS/UKMET AND CANADIAN DIFFER SIGNIFICANTLY FROM THE RECENTLY ARRIVED 12Z ECMWF BETWEEN DAYS 3-5 ALONG THE EAST COAST. MEDIUM RANGE COORDINATED A 12Z UKMET/GFS COMPROMISE FOR THE FRONTAL STRUCTURE AND SPOT LOW POSITIONS. THIS ALLOWS FOR SOME WRAPAROUND MOISTURE TO PRESENT ITSELF ACROSS THE MID ATLANTIC STATES PER GFS/GEFSMEANS...VS THE DRY 12Z UKMET/ECMWF SOLUTIONS. THE 12Z ECMWF APPEARED TOO WEAK OVER SOUTHERN CANADA ON DAY 5 AND CONSEQUENTLY DOWNSTREAM...HAS LITTLE TO NO SURFACE REFLECTION IN THE WESTERN ATLANTIC AFTER DAY 5 They don't seem overly happy there with the ECM operational run. Then this from the Aviation forecast for Iowa: THE REST OF THE FORECAST WILL REMAIN DRY. THE OTHER STORY WILL BE THE TEMPERATURES AVERAGING 10 DEGREES OR MORE ABOVE NORMAL THROUGH AT LEAST THANKSGIVING BEFORE ANY COOLING BEGINS. SOME SIGNS FOR CONDITIONS RETURNING TO NORMAL OR BELOW BY MONTHS END WITH A SHIFT IN THE MJO PATTERN AND THE POTENTIAL FOR SOME CROSS-POLAR FLOW DEVELOPING POST DAY 10. In terms of the ECM ensemble members at 168hrs: http://www.ecmwf.int/samples/d/inspect/catalog/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!168!pop!od!enfo!enplot!2009112700!!/ That shows a mixed bag, theres some good, bad and downright ugly stuff if you're looking for colder conditions!
  8. nick sussex
    Can we order the JMA for tomorrow across all the models? The ECM does look very messy and overly complicated past 144hrs but the key thing is to get some energy heading se into the Med, this happens before then and thats the main positive to take from its output. Overall some positive signs for cold this evening but until we get agreement on the limpet trough and what happens to that then theres still a good deal of uncertainty.
  9. nick sussex
    A more amplified GFS run but the limpet trough still refuses to disrupt and split in time, then the lower resolution takes over and manages to undercut the ridge with a positively tilted trough! The UKMO is a little better at 144hrs with a bit more amplification, it looks like we'll see a phasing of two lows off the eastern USA and its the amplification of this troughing that will determine how much of a ridge is pushed ahead. Time for our first shortwave drama of the winter season, its looking like we will need to see the trough split far enough west and a shortwave to be ejected se'wards. So its over to the ECM to deliver and do the right thing!
  10. nick sussex
    Lets hope the GME at 72hrs is a taste of things to come. Compare its upstream amplification with that shown on the earlier GFS 06 hrs run for the same time: GME 12hrs GFS 06hrs
  11. nick sussex
    Yes regarding the GFS I don't have a problem with 4 runs per day but the higher resolution should be extended to 240hrs and the rest dropped. Even I wouldn't want to lose the 06hrs and 18hrs, what would we talk about during the afternoon and night if they went! NOAA still mention some uncertainty with the pattern over the eastern USA so once thats resolved we'll have a better idea as to how that will impact the limpet trough.
  12. nick sussex
    Thanks, I would be almost breaking out the champagne if the models all followed the ECM lead and sent that shortwave se into the Med, especially as this is getting into the more reliable timeframe. It would be great to see that trend on tonights model runs and would save alot of shredded nerves in here!
  13. nick sussex
    Unfortunately if you look at the current verifications stats the GFS 06hrs run in the NH is doing better than the rest of its output. Even the GFS 18hrs is doing second best. Thats not to say that will remain the case but although I'm happy to trash any of the lower resolution GFS output we can't just ignore this run in the higher resolution because we don't like it. http://www.emc.ncep....gmb/STATS_vsdb/ Go to the bottom and click on GFS 4 cycle stats. You'll see the comparisons there. The GFS in higher resolution is plausible and is closer to the UKMO at 144hrs, if the pattern flattens out upstream then the GFS 06hrs run is a likely scenario. For this reason until I see cross model agreement with energy being ejected se into the Med within the more reliable timeframe then I won't be convinced of a quickish change to colder conditions. If we miss that opportunity then it will take much longer to change the pattern. I'm not saying that it still won't happen but that the longer it takes the more likely another complication will arise. This is the ECM at 144hrs from the NH: You can see here the trough splitting and that piece of energy about to be ejected se towards the Med. Originally we had hoped for the troughing to sink south/se now we are more relying on the split with energy heading north and south. Once you have developed lower pressure in the Med as seen here on the ECM at 168hrs: Then thats the trigger for the pattern change as any ridging to the north is supported by those lower heights. We know from all the output that the troughing is likely to be pulled northwards, without the split and shortwave ejection the road to colder conditions relies on yet more events being favourable upstream. Although we do have signals to develop higher pressure to the nw the sooner we can get that energy into the Med the greater chance of success.
  14. nick sussex
    I see no mention of the very underwhelming GFS 06hrs run which is perfectly plausible if the upstream pattern flattens out too quickly. The interest yet again comes towards the end of the lower resolution output! By far the best output today is the ECM because at 144hrs its splitting the trough and sending a shortwave se into the Med, the UKMO looks again flatter upstream than the ECM. Whilst the NAEFS might be nice to look at it means nothing unless we see the models moving the good synoptics into the earlier timeframe. I'd concentrate for the timebeing on events within 168hrs and start praying that the other models follow the ECM and eject some energy se'wards around 144hrs, otherwise its a longer haul to colder weather with the proviso that in the meantime yet another variable could pop up!
  15. nick sussex
    Yes the same old routine from the GFS in its lower resolution output. They really should do the kind thing and put it out of its misery. Bin the lower resolution and work on improving the model overall and taking it out to a maximum 240hrs like the ECM. It might be less entertaining but surely would be much more productive.
  16. nick sussex
    I think the best that can be said about tonights output is shows some promise but must try harder! Putting aside the more interesting later output that leaves us with the limpet trough agreed across all the models within 144hrs. Then the upstream pattern shows differences between the GFS and ECM, not to flog a dead horse and for fear of sounding like a broken record but the more amplification upstream the better chance of a favourable outcome in terms of colder weather. We are likely to see an interaction between low pressure heading east out of the USA and low pressure heading se out of Canada, these phase together and its the amplification of this troughing that can help deliver a stronger ridge ahead exerting pressure on the limpet trough to disrupt. The GFS in the higher resolution has much better amplification of that troughing upstream although it continues its obsession with the limpet troughing for too long, the ECM has a more perilous way forward for cold lovers. All in all we are reaching the timeframe where the disruption to that troughing will become better modelled, by the end of the weekend we should know whether its another false dawn or a pattern change.
  17. nick sussex
    It looks like its that time of the year when we will once again be discussing shortwaves and trough disruption! Could be another February 2012 revisited with the ensuing drama as the models disagree where to eject the shortwave. Overall given where the PV is expected to set up then its really going to have to be an initial east/ne flow, hard to see any northerly appearing unless the pattern retrogresses later.
  18. nick sussex
    The GFS is certainly making a meal of getting rid of that trough,but overall not a bad start and the UKMO looks a bit more amplified than this morning. Given this trend the ECM should deliver a decent run this evening.
  19. nick sussex
    As we can see from the GFS 12hrs its more amplified upstream. We have to hope that this re-amplification trend will gather pace and send that limpet trough packing.
  20. nick sussex
    Looking at todays output so far it now looks like we'll have to go to plan B! The upstream pattern flattens out too quickly and as we saw from the ECM 00hrs we then have to wait for another opportunity much later in the run to get some energy to dig se. The problem as we've seen is that the good synoptics keep getting pushed back rather than moving forward towards the 144hrs timeframe. There is still alot of uncertainty with the upstream pattern in terms of how much it amplifies but IMO we need to get rid of that troughing as quickly as possible and this means we have to hope the models move back towards the more amplified patterns of a few days back. The problem with delays as we've seen is yet another variable often pops up so seeing good outputs stuck at 240hrs doesn't really give us much confidence.
  21. nick sussex
    Personally I have no time for any of the lower resolution output of the GFS and my thoughts are well known in here regardless of what it shows. This is even more pertinent with the current synoptics where the distribution of jet energy is crucial for the outcome. I will however comment on its higher resolution output which goes back to what I've been droning on about for much of the day, we do need to maintain sufficient upstream amplification to finally get rid of the limpet trough, as we saw from the GFS the pattern flattened out and hence that trough just sat there before edging north, regardless of its better output later in the lower resolution the chances of getting from that underwhelming higher resolution to the more appealing synoptics later are IMO extremely low. We need to see the trough at least split much further west or be forced south,and the upstream amplification plays a crucial role here. Given the set up if we get the right upstream amplification then the rest will take care of itself all this will be determined in the higher resolution, theres a reason the GFS often comes out with four different scenarios in its lower resolution each day, its just to entertain this thread! View it as entertainment but my advice don't take it too seriously especially when theres a suggestion of a pattern change. Adding to SM's post if we hark back to last year which were the two models that made a dogs dinner of that February cold spell, the GFS and more surprisingly the UKMO couldn't handle a shortwave and caused alot of drama in here and that was within 144hrs. The ECM might not be perfect but certainly for European high pressure its streets ahead of the rest.
  22. nick sussex
    Interesting comments from NOAA this evening: ONE OF THE BIGGER SHIFTS IN THE GUIDANCE IS HOW THE 12Z GFS STRONGLY DIFFERS FROM ITS OWN 12Z MEAN. THE 12Z GEFS MEAN HAS TRENDED TOWARD A MORE AMPLIFIED 500-MB SOLN BY D6/D7 OVER THE WRN ATLC WHILE THE OPERATIONAL RUN IS FLATTER AND MORE PROGRESSIVE. MEANWHILE...THE 12Z CMC APPEARS TO HAVE COMPLETELY CHANGED ITS TUNE FROM THE 00Z RUN WITH FEATURES LITERALLY SEVERAL HUNDRED MI AWAY FROM ITS CONTINUITY. THE 12Z UKMET LIKELY SHOWED THE BEST RUN-TO-RUN CONTINUITY...ALBEIT OUT TO D6 GIVEN THE MODEL STOPS AT FHR 144. THE 12Z ECMWF SEEMED TO MAINTAIN THE SAME OVERALL PATTERN ALOFT BUT WITH PLACEMENT ISSUES...ESPECIALLY BY D6/D7. OVERALL...HPC MADE A COUPLE OF MODIFICATIONS TO THE GRAPHICS. FIRST...GIVEN THE SHIFT IN THE 12Z GEFS...IT REPLACED THE 00Z RUN WHICH LEAD TO MORE 500-MB AMPLIFICATION OVER THE WRN ATLC AT D6/D7 ALONG WITH A BUDGE WWRD OF THE SFC CYCLONE. ADDITIONALLY...HPC SHIFTED SOME OF THE FRONTAL SYSTEMS ACRS THE CONUS TO BETTER FOLLOW THE DERIVED WIND GRIDS WHICH WERE NOT INITIALLY AVAILABLE DURING THE MORNING PACKAGE. Some good and bad news there, we want a more amplified upstream pattern. In terms of the UKMO even though its showed continuity in this instance we want it to be continually wrong as its output is not great!
  23. nick sussex
    The block you see is really just the starter, it will deliver some surface cold but the important feature is to the north. If you look north you'll see that ridging heading into the Arctic from the Aleutian high, the PV is split, generally in this situation as the upstream pattern amplifies the signal to retrogress will pull a piece of the PV south into Russia, the other piece which is already in nw Greenland edges further west and that ridge to the north drives the AO well into negative territory. At the same time the high to the east will separate with one lobe edging west the other flattened by falling heights to the east. You should then end up with troughing to the east and high pressure to the nw, thats in a perfect world. If it was that simple I'd be ordering the sledge, as is the case it could all go terribly wrong! We can just keep our fingers crossed and hope for the best!
  24. nick sussex
    Impressive continuity from the ECM with this run a mirror image of its earlier 00hrs. Still the matter of the UKMO and if you look at that at 144hrs and compare it to the ECM theres a big difference. Certainly we need to see the UKMO come on board as thats still a concern with the trough much further east and the pattern upstream already flattening out. At 240hrs take a look at the NH chart, that Aleutian high is about to carve its way cross polar !
  25. nick sussex
    Thanks for that. All models go through good and bad patches but for some reason over the last few days the UKMO has fallen off a cliff in terms of its anomaly correlation. It's most evident at 144hrs, I know they have that new ensemble system which helps them rather than using the ECM ensembles. So I would expect those modifications occured with those taken into account. Don't get me wrong I like the UKMO and generally place it above the GFS at that range, at the moment the ECM looks most stable out of all the global models.
×
×
  • Create New...