Updated 27th February
Covering the period 6th - 28th March
Mean temperatures will range from very close to the 1981-2010 normal over Scotland and Northern Ireland, to about 1C above in southern England, with northern England, the Midlands and Wales about 0.5C above.
Rainfall totals will be above normal in the south of England, slightly below normal over the rest of England, Wales, southern Scotland and Northern Ireland, and significantly below normal in northern Scotland.
Sunshine totals will mostly be slightly above normal, but will be significantly above normal in northern Scotland.
Monday 6th March - Sunday 12th March
This period will have low pressure systems tracking further south than usual, bringing periods of cloudy and wet weather, but around midweek there will be a weak build of high pressure to the south-east which will bring relatively dry conditions to eastern parts of Britain.
Although there is uncertainty over the precise timing of frontal systems, the 6th and 7th are expected to be predominantly cloudy and wet across the southern half of Britain, with brief drier brighter interludes in between the rain belts, as low pressure systems will track from west to east over the south. It will be drier and brighter over Scotland, to the north of the weather systems.
Temperatures will be a little below normal for the time of year over much of the country, and the weather systems will produce some snow on high ground, but with rain near sea level.
The cooler and unsettled regime will return towards the end of the week with weather systems coming back in from the west, with the ridge of high pressure retreating away eastwards. It won't be as persistently dull and wet across central and southern Britain as near the beginning of the period, with a more mobile pattern bringing brighter showery interludes in between the rain belts.
Mean temperatures will be up to 2C above the 1981-2010 long-term normal in southern England, but very close to average over Scotland, Northern Ireland and northern England.
Rainfall totals will be above normal over much of western and southern England, but below normal in the north and east of Scotland, and near normal elsewhere.
Sunshine totals will mostly be below normal but will be near or rather above normal in eastern Scotland and north-east England.
Monday 13th March - Sunday 19th March
The westerlies will fizzle out during this period, with slow-moving, slackening low pressure systems close to the British Isles early in the period, bringing mostly cool, showery conditions with occasional longer outbreaks of rain (and hill snow). At present, there is considerable uncertainty over where and when the longer outbreaks of rain will occur, but the rain and showers will tend to fade around mid-March. A weak ridge of high pressure will cover the British Isles late in the week, resulting in dry and increasingly bright conditions with temperatures recovering close to or just above the seasonal norm. Highest pressure is expected to be in the eastern Atlantic which means that western areas are most likely to be sunny.
Mean temperatures will be 0 to 1C below the 1981-2010 long-term average over much of the country. It will be wetter than normal in eastern England and south-east Scotland, but generally drier than normal in western Britain. Sunshine totals are expected to be above normal in the west, and in northern Scotland, but near to slightly below normal in eastern Scotland and eastern and central parts of England.
Rest of the month
Monday 20th March - Tuesday 28th March
A relatively blocked pattern is expected to continue early in the period, but with a transition towards a more changeable west to north-westerly type towards the end of March. Temperatures will mostly be above normal early in the period, but falling close to or just below normal near the end, overall about 1C above the long-term normal in most regions. Rainfall totals will generally be below normal in spite of a relatively changeable end to the period, with fronts tending to move through quickly and with relatively small rainfall amounts. Sunshine totals during this period will mostly be above normal, especially in eastern parts of Britain.