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Steve Murr

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Everything posted by Steve Murr

  1. ^^ Extreme hybrid version of a displaced ( North ) -EPO ridge Sounds good....
  2. Just floating this chart from the archive for possible future reference.....
  3. GFS 114 18z V 120 12z Headbang smiley - finally the GFS is on board 18Z FIRST
  4. I know its been posted by the 18z ICON has the -4c line over London heading into Weds now- The models have swung rapidly back to cold & blocked in the last 24 hours lead by the UKMO- There of course may be a 24-48 hour period eventually when the atlantic gets in however that doesnt last for to long!
  5. I didnt need to guess who would be in this thread this eve Buxton temp 0.6 & 0.0 DP - snowing in the market car park.
  6. Morning Expecting reports of deeper snow over the higher routes of mid wales / Shropshire today maybe somewhere gets to 6 inches !
  7. A sizeable swing to the UKMO from GfS 18z plunges Scotland into Further cold with more slide on the low & minimal phasing -4c line down to the coast mon & very Cold for Scotland.
  8. The front has stalled now so the midpoint of wales at elevation could do very well indeed 3-4 inches poss >200M
  9. Just a NB on the models - I really doubt the milder air predicted by the 00z & yesterdays GEFs will make it to Scotland...
  10. Hard to make a definitive forecast however up till today all the models had no cold coming in from the NE now the UK does also the atlantic looks like sliding SE as opposed to moving gently East Also look at the GFS mean now from 06z to 12z (156 > 162 ) 06z first note the circular low pumping warmer winds ahead where as the 12z its oval shaped & appearing to slide
  11. All the commentary on GFS yet just 1 above on UKMO Lovely upgrade there with a potential wintry event day 7 ....
  12. Glosea is a high top model & will be able to factor in the SSWs into the seasonal forecast however its only in the last week or so this has become more visible in the models - based on that the next seasonal run of the models in particular Met office & ECMWF will be very interesting...
  13. For viewers in this thread who don't always post heres a few numbers & signposts as we head towards December ( say from 20th Nov onwards ) These are for Stratospheric Zonal wind @10HPA Current Speed 41.8 M/S which is classed as a strong vortex. ( Old date record for today 2015 - 40.2 M/S Average December Start point - 30 M/S Average Peak zonal wind ~ Ironically ~ Christmas day 38 M/S which is why statistically Christmas day is mild. Lowest End of November > (20th Nov ) zonal Wind value 7 M/S 2009 - December AO was -3.4 Earliest Decemeber SSW was 1981 & the AO was -1.26. Current lowest forecast from last 4 GFS operational runs continue to creep down ( very consistent ) 12.5M/S but notice the trend. The lowest 00Z ENS value is 4.19 M/S however todays havent been updated yet- Glosea yesterday was modelling the same transition yesterday with a powerful warming however perhaps on the interim between late November shows a signal for lower polar heights - So based on that we see the AO peak negative then neutral / pos until the warming & deceleration downwells- Im not 100% convinced on that but we will see. So benchmark the date 27th November as time when the deceleration moves to its final phase....
  14. Strong is +41.2M/S Cant remember the weak value - Probably sub 15 M/S
  15. Minimal time to post this eve however I would love the GEM 12z to be correct- Currently out 150 looking great...
  16. The models continue to display the hallmarks of a Run in to Winter that certainly is far from the Norm - of course if your just living under the umbrella of zonal is coming just like every winter then that direction may be displaced. NW & TWO have been around for a good 10 years & at the very least that produces a bank of data where the period 01 Nov to say 20-30 Nov generally produces info that can safely predict the overall hemispheric pattern for December- More so the pattern heading from Mild zonal Nov into mild zonal Dec & less occasionally Cool / Cold Blocked Nov into potentially Cool / cold Blocked Decembers. If we stand here on the 20th of November there are 3 key hallmarks of the stratospheric imprint that will certainly shape the December forecast. 1) Strength of stratospheric vortex & how thats coupled with the atmosphere 2) 10HPA zonal wind speed at the Entry point to winter & Any disruptions ( ie Warming ) 3 ) Are we in a Strong +Nino phase Polar height 2009 V 2011 What is easy to identify is the Novembers where the strat has coupled into the tropospheric vortex Mid / Late November & its +AO all the way through December ( Especially in Nino Years ) 2015 is a great example. November 2019 almost at the midway point & one would be forgiven in thinking that we are going to be blown away to kingdom come with a very strong vortex- Today we hit + 40M/S & the technical definition of a strong vortex is +41.2 M/S. However the Stratosphere is still disconnected from the troposphere - so up the top 1-30HPA she is spinning away however sub 150HPA things are pretty placid- infact the NAM index in negative mode actually reinforces the disconnect with NH weather patterns that further create disturbances upwards ( upward heat flux ) to the strat ( namely the Aleutian low & Scandi High ) The route cause of why 2019 is so disconnected could be attributed to Arctic Amplification due to the ice loss however the Sunspot activity impacting the jet could also be a factor. This means that with 19 Days of November to go we find ourselves in the position where the forecast is for the Strat jet to be under continual attack & forecasts go across a 16 day speed from record Positive to around 10-15 M/S - ( Rem the start of December is usually in 30 M/S. The lowest number found on the GFS 00z Ellipses today was T384 just 5 M/S ( The Mean was about 15 M/S ) In these scenarios it appears to be a displacement rather than a split Late Nov 2009 Merra date recorded the wind to get to 7M/S which really impacted the December AO coming in at -3.4. So, with a long but less volatile timeline the models at 10HPA paint a picture where we move into a position last seen 10 years ago & that timeline being late Nov is the precursor to Decembers AO pattern. Its important to note the trending at the moment is with every run at 16 Day the zonal mean drops further which is great however lets get to day 8 & see where the trend is then. We all know that a steeply negative AO isnt always a slam dunk cold shot for the UK however its a good start point.... So this is why we are seeing these major blocking patterns appearing, also if the models have the displacement correct & the zonal wind reduces below 15M/S for the tail of November then predicting a negative AO pattern for December should be fairly easy.....
  17. Very Cold surface well & truly embedded on ECM - Very frosty!
  18. Very cold with some Sleet / snow across the UK... Wait to you see the 850's
  19. Lovely ECM 168 ( Euros on a par at 144 ) which is always a good thing..
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