Good morning everyone
We have seen some Exceptionally consistent overnight Multi-Model Guidance with excellent Medium Term agreement - something not seen in quite some time. At the moment, it appears that ECMWF is leading the way on the general evolution, but a blend of ECMWF/UKMO/GFS/UKMO is likely into the Medium Term.
It should be noted that from T+132 - T+144 onwards now, quite exceptional Northern Blocking is indicated. The tend at the moment appears to be to take the main core of blocking even further North with each and every evolution.
Winds eminate from an Easterly/Northeasterly direction throughout. For the coming week as a whole, conditions are likely to remain cold to very cold at times, with signs of even deeper cold arriving towards Day 5/6.
While there will be a risk a light sleet & snow flurries/showers in Eastern areas during later on Monday & Tuesday, the pattern will generally be Anticyclonic Easterly, with limited snowfall potential in general.
During the midweek period, conditions may become somewhat even more slack, but with winds still generally Northeasterly, as the main core of blocking becomes situated to the immediate North. In addition, at this point, even more extensive Northward Warm Air Advection is indicated, setting up a prolonged blocking pattern all across the variable North.
Towards Friday onwards, there are some continuing indications that a more cyclonic Easterly pattern may well become established, with an enhanced threat of snow showers in Eastern areas in particular. Rather more deep cold is advected across the country at this point also, with main blocking centres over Scandinavia and Iceland.
Day 7 - Day 10
NWP Guidance also remains very consistent for this period, with a marked signal for extreme Northern Blocking to develop & a solid retrogression phase of the main blocking centres towards Greenland. As a result, an even more unstable Northeasterly to Easterly flow becomes established across the UK & Ireland, with an enhanced threat of snowfall once again. Conditions remain very cold throughout with a deep continental sourced airflow.
In addition to the recent warming event at the 30mb level, a renewed phase of warming is now taking place, which provides even further support for potential Northern Blocking towads Day 10 - Day 15:
30mb Temperatre Trend
Between Day 10 & Day 15, we are likely to see a more West Based -NAO evolution become established, with the main core of blocking transferring into Western Greenland & the Canadian Arctic. This also allows for a more cyclonic cold pattern to become established & is something to monitor over the next several days.
In summary then, there are solid indications of a cold spell lasting through to Day 5 at least this morning. There is the risk of light wintry showers in Eastern areas on Monday & Tuesday, but nothing significant is expected at present. The midweek period will see conditions falling even slacker, with light Northeasterly to Easterly winds & further overnight sharp to severe frosts. Towards Day 5/6 onwards, a somewhat more cyclonic Easterly/Northeasterly pattern is indicated, with exceptional Northern Blocking throughout, as indicated by the 6-10 Day CPC 500mb Height Anomoly Chart:
CPC 500mb Height Anomoly - Through to Day 10