Updated 13th March
Covering the period 20th March - 11th April
Mean temperatures will be within 1C of the 1981-2010 normal over much of the country, generally 0.5-1.0C above in southern and central England and south Wales, but 0.5-1.0C below in western and northern Scotland, and within 0.5C of normal elsewhere.
Rainfall will be above normal in East Anglia and the south and east of England but much of Scotland will be drier than average, particularly the west of Scotland. Elsewhere rainfall will be close to or just above normal, with a wet end to the period offsetting relatively dry conditions early on.
Sunshine will be a little above normal in north-west Scotland and in south Wales and south-west England, but near or slightly below normal in other parts of the UK.
Monday 20th March - Sunday 26th March
The first half of this week will be changeable and quite cool, with predominantly bright and showery weather, interspersed with some longer spells of rain moving from the west at times. High pressure will build from the west towards the end of the week, bringing quieter weather.
The 20th is expected to be a bright and showery day, with the majority of the showers in the north, where hail will be quite widespread and there will be sleet and snow in the heavier showers across Scotland, and accumulations of snow on high ground.
It will be milder with fewer showers in the south. The generally showery regime is expected to continue until the 23rd although one or two frontal systems will move from west to east and bring longer outbreaks of rain particularly to the south. Temperatures will be close to or a little above the seasonal norm in the south but it will be a little cooler than average in Scotland, Northern Ireland and northern England, with the showers again wintry at times especially over high ground.
High pressure will build from the west towards the end of the week. There is some uncertainty over the precise positioning of the high, but it is expected that a chilly northerly wind will blow across eastern England on the 24th and possibly the 25th as well, bringing cool and cloudy weather, with sunnier weather in the north and west of the country. By the 26th the high will be centred over the south bringing warmer sunnier weather to the south and east, but cloud and drizzle to western Scotland, Northern Ireland and north-west England.
Temperatures during this period will be about 1C below the 1981-2010 long-term average over much of Scotland, but about 1C above in south-west England and south Wales, and very close to normal elsewhere.
It will be wetter than average in most southern, central and eastern parts of England, but drier than average in the north and east of Scotland.
It will also be a sunny week over much of Scotland, Northern Ireland and north-west England, but East Anglia and the south-east will have a shortage of sunshine.
Monday 27th March - Sunday 2nd April
I expect this period to start warm and anticyclonic with southerly and south-westerly winds and there will be a general increase in sunshine amounts with some dry continental air being pulled into the air stream over the British Isles. It won’t be unusually warm for the time of year, with highs generally between 14 and 18C, but the warmth will prove persistent early in the week. However, as we head into the beginning of April, colder and more unsettled weather will push in from the north-west, with the possibility of a short-lived (24-36 hour) northerly outbreak bringing some wintry showers and overnight frosts. Temperatures will tend to fall rather below average by the end of the week, although not exceptionally so.
Temperatures will come out between 1 and 2C above the long-term normal due to the warmth early in the week. Rainfall totals will mostly be below normal except in Northern Ireland and western Scotland, with sunshine totals below normal in north-west Scotland but above normal in most other parts of the UK.
Rest of the month
Monday 3rd April - Tuesday 11th April
This period will see the weather turn unsettled with low pressure systems taking a more southerly track than usual when moving from west to east close to the British Isles, and relatively high pressure around Greenland and Iceland. This will mean generally wetter and cloudier than average weather across the UK, with temperatures close to or slightly below the seasonal norm. Northern and western Scotland will be the main exceptions, with north-west Scotland expected to be both drier and sunnier than average.
Mean temperatures during this period will mostly be between 0 and 1C below the long-term normal, but with near-average temperatures by night and rather below average temperatures by day. Most parts of the UK will be cloudier and wetter than average, but rainfall will be close to normal in Northern Ireland and north-west England, and below normal in western Scotland, and it will be sunnier than normal in the north and west of Scotland.