High pressure over France, extending up over southern England for a time.  Low pressure in the Atlantic moving up from the southwest to the north of Scotland with a second area of low pressure approaching from the west later.  Initially a southwesterly airflow, becoming westerly.

Friday 25^th starts with scattered showers in the West Highlands overnight, but elsewhere mostly dry.  Low cloud slow to clear in places, especially around the SW Moors and Pembrokeshire which could remain rather misty to low levels for much of the day, especially towards the coasts.  Generally though becoming bright in most parts for a time but with some moderate rain pushing northeastwards across N Ireland and into Scotland by afternoon.  Some rain also also likely to affect Wales, particularly Snowdonia, and northern England through the middle part of the afternoon, though probably clearing by early evening.  Through the afternoon, rain likely to intensify across Galloway and the Western half of the Highlands, but with the Cairngorms and eastern glens probably remaining mostly dry – though rather cloudy - till late in the day, and even then missing the worst of the rain.  It will be pretty mild though and rain is expected to cause some melting of the snowfields.  Clouds generally down below summits in all parts, though perhaps lifting across eastern parts of Wales and the Southern Pennines later.

Southwesterly winds rather strong in the north and west, making it feel a bit colder here, especially in the rain.  But towards the east especially feeling rather warm.

Low cloud and rain continuing overnight across much of Scotland and this likely to persist through much of Saturday 26^th, slowly moving further back south into Cumbria, the North Pennines and later Snowdonia with cloud levels falling accordingly after a fairly bright start.   Becoming a bit brighter across the Northern Highlands by evening with cloud here starting to break. 

Further south though it should be a dry day with variable cloud, at times a bit hazy, but some good sunshine once any early mist and low cloud clear and generally feeling rather on the warm side, indeed likely to be the warmest day of the year so far in many southern parts.   Winds still strong in places though, especially across the NW Highlands; lighter towards the south and east.

Patchy, mainly light, rain reaching South Wales, the Peak and SW Moors in the evening and continuing to push further south and east through the night, clearing most upland areas – except perhaps N York Moors – by morning.

Sunday 27^th should thereafter start off dry for most upland areas, with variable cloud, slowly lifting above summits. However by late morning, and especially through the afternoon, it looks like we’ll see some widespread showers develop.  These are quite likely to be heavy and thundery in places, especially across Ireland, Wales and the Southern Pennines.  Still fairly warm in the sunshine between showers.  Any lingering low cloud and rain across the N York Moors should clear through the day.

A moderate SW or westerly breeze for all parts

Monday 28^th looks set to be another showery day and there’s a chance these could well be heavy at times.  Blustery westerly winds.  Feeling cooler again with temperatures just about up to average for late April.

Through Tuesday low pressure settles over Britain and looks like hanging around for much of the week, keeping it unsettled, windy and wet and bringing temperature down below average.  Some snow possible at times over higher summits in the Highlands.  Continuing unsettled through the May Bank Holiday weekend, though there's the possibility of high pressure to the south ridging northwards to give some southern parts a slightly warmer more settled spell – no certainty though.

Anyone walking/climbing/ski-ing in the Highlands is advised to check the Latest SAIS avalanche risk reports before setting off.

TOI  24th April 2008