Cavehill Snow

I cannot recall seeing such crazy synoptic patterns in a long time - probably more fantastic than any of the charts drawn up by snow mad members when they were little nippers as some were reminiscing the other night. Reasons not to happen:- Azores high in Iberia, too much Atlantic energy, MJO unreliable, our crud luck....... At least the charts brought a smile

Why is that low shown in the Norwegian Sea almost every run? Is it because of the temperature differential of cold Siberian air hitting the warm N. Atlantic ocean, or, is it a consequence of the pressure pattern with relatively high pressure circa Iceland / Greenland and the low pressure coming off the ESB and extending into the Atlantic?

Still learning - a quick question. Can we really expect the Arctic high to exert influence on the low pressure belt at our latitudes to help push them south if the Geop z500 colours for the Arctic high are light blue? Generally we look for yellow and orange colours to be indicated for a strong Greenland high to have confidence in its ability to exert a positive influence in our neck of the woods. The current GL which has been green and has been trending towards west based -NAO has had only very limited influence in our sphere. Do we need the Arctic high to intensify and / or move further south

It would be good if it was to happen, unfortunately the trend has been over the last few days has been to lift the pattern further north and away from us. However you would think that if pressure could rise to our north in some way (perhaps the Artic high could allign better with the GL ridge) and shunt the whole patter south, then we would be in a great position to benefit as per your 1978 chart.

Thanks for the chart and clarification

Look at the unusual pattern of isobars between Iceland and NW Scotland - it looks like the isobars cross over one another on NW coast of Scotland. Usually the isobars blend in their path from one high or low pressure to the next. I think the highly unusual & conflicting signals are causing great difficulty for the algorithms.

After the cut & thrust of winter is over, it would be great if you were able to do an educational post regarding how to interpret the newly available ECMWF charts to which you refer in the attached post.

Not sure on that. But the col (area with no isobars) is unusually large. It is even more unusual when you see the tightness of the isobars throughout the remainder of the chart. Normally cols are larger in slack pressure gradient scenarios which this chart is not.

Some many conflicting signals all trying to impose themselves at the same time - so charts look unrealistic. Just look at that area without any isobars - stretches from N Spain to just south of Iceland and from the Isle of Man to about 500 miles of west coast of Ireland. Will never happen in reality

I know you concentrate on the NOAA anomolies charts, but do you know if the EC / GPS version pick up on this before the GPS model runs?

Just trying to learn, a few questions if I may:- Has the trop been uncoupled from the strat so far this year, or has the trop been leading the strat? If the stat is not leading the trop at time the time of SSW occurence, can the trop lead the response on this? TIA

I am mystified by this also - i acknowledge that many are looking for a cold / snowy outcome for our neck of the woods, but what i am perplexed by is that there will be much less high latitude blocking anywhere in the northern hemisphere @240 hrs compared to what we have seen over the last week.

Not so sure ref UKMO, it is very much a short range model out to 144hrs. Weather predictions up to 120hrs are very accurate nowadays (except for a few notable very complicated scenarios like the present), and the UKMO 144 hrs this season have been very hit & miss.

Hi, i'm a beginner, so please go gentle. I noticed that there has been a small trough in Moscow area on the charts for days which seems to me to prevent the 1055mb high pressure west of the Urals linking with the 1030mb ridge over Scandi. Could this be delaying a colder regime setting in for us?

Quick question from a novice - is the icelandic shortwave @ECM216 nailed on to drop down, regardless of how far it goes n/s & e/w? Also, is it possible for the shortwave to drop favourably for us so that the eastern flow from Russia through Scandi can link up with Greenland heights? Tia