A lovely day for many, warm sunshine bringing temperatures up to around 20*C quite generally. It all to do with an area of High Pressure, which is, situated right on top of the UK today. Unfortunately the high pressure is not completely cloudless and it is likely that to the North and West for example Scotland and Northern Ireland it may be rather cloudy and dull with even the possibility of some drizzle. As we mover South and East into Northern England, Wales and the Midlands things should be dry with sunny spells, it is unlikely there will be wall to wall sunshine unfortunately but it will still be a real taste of summer. As we move on into the afternoon Cloud may well build to bring some sharp showers in such places as the East Midlands, Central and southern England and the South East. These showers may be thundery in isolated spots, but there will be nothing severe. As we move towards the evening A trough is set to clip the east coast, this may well cause shower activity to 'pep' up for a while. A trough is a feature, which can aid instability in the atmosphere and can cause showers to develop.
An interesting day. The morning should start off dry and bright with sunny spells however yet again; some persistent cloud will plague Western Scotland and Northern Ireland and Western Wales. Elsewhere expect sunny spells, with the best of the sunshine the further East you go. Temperatures again generally 20*C but maybe a touch higher, especially in prolonged sunshine. The tricky part of the day comes from Midday onwards. A trough that I have said causes instability and can act as a trigger for shower development will lie from North Wales Across to Eastern England. This is the line where showers and thunderstorms will begin to develop. This area of instability caused by the trough will move South and East throughout the afternoon. Conditions for convective showers and thunderstorms are good. Lifted index will be as low as -3 with CAPE getting up to 500j/kg by the early evening. The lifted index AND CAPE are both used in the forecast of convective showers. The lower the lifted index is AND the higher CAPE is the better in relation to thunderstorm or shower development
Unfortunately the day is likely to be spoilt by an occluded front moving slowly South Eastwards from early morning onwards. This is likely to reverse the weather pattern we have seen over the last few days. The South and East are likely to be plagued by cloud and some heavy rain, while the further North and West you go the more likely you are to experience some sunshine. The best places for some sun early on are likely to be Scotland and Northern Ireland. As we move south things cloud up slowly. Northern England and North Wales likely to has some sunny spell and brightness but any further south than this and its looking cloudy and damp. As the day wears on the South and East will stay cloudy and wet while unfortunately Scotland and Northern Ireland cloud up again. This will mean that a section from Northern England into North Wales is likely to have the best of any sunshine AFTER mid-day. Temperatures likely to be disappointing compared with previous days. 14*C likely to be the max temperature in the Midlands and Northern England. 16*C may be seen in central and Southern England while 10-11*C likely in Northern Ireland and Scotland. This is all tied in with cooler air working its way southwards. By 6pm the occluded front should be near to the south coast and across central and southern England. This timing may be crucial as lifted index and CAPE may be sufficient enough to spark of some convective activity around the area of the occluded front.
Pressure is dropping today and the winds are causing a slack northerly to develop. Cooler air is piling in from the north and making things feel horrible compared to the previous few days. The day is tricky to forecast for as there is likely to be a band of cloud moving southwards and it�s pretty hard to place it accurately right now. It is likely that Northern Scotland will see some cloud breaking at times to bring some sunshine and brightness. This is likely to be the case in Northern Ireland as well. However As we move into Northern England a band of cloud will mean little brightness if any for the area, and this is likely to extend into North Wales. South of this it�s the same story as Scotland and Northern Ireland. This band of cloud will inch its way south throughout the day. An occluded front runs down the East coast, this is likely to be associated with the band of cloud AND also bring some light and patchy rain. Temperatures looking as if they will reach 14*C in the south and East, while struggling to 11*C elsewhere.