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Saturday begins with a widespread frost. The rest of the brings a lot of dry and bright weather but in eastern counties there could be a few light wintry showers.

It will be cold with temperatures ranging from 3C (37F) to 5C (41F) this afternoon. See the rainfall and precipitation type radar for the latest view.

Tonight it stays dry and a sharp frost quickly returns. Tomorrow it remains dry for most of the UK but near the east coast light snow showers are possible. Temperatures will be down on today's values and a brisk easterly wind adds to the chill.

The Big Freeze

By Monday unusually cold air originating in Siberia will be covering the UK as a "Beast from the East" weather pattern develops. That describes the set-up where the easterly flow on the southern flank of high pressure centred over Scandinavia pulls air from Siberia westwards across Europe.

Snow showers initially affect eastern and south eastern areas. Through Monday afternoon they probably become more frequent and there is the possibility of a Thames Streamer bringing snow towards London.

During Tuesday and Wednesday the freeze intensifies. Snow showers are expected to be widespread and heavy in places with significant disruption to transport in parts of the UK. The showery nature of the snow means local conditions will vary significantly but computer models show accumulations to be most likely in parts of central and and eastern Britain.

The chart below from this morning's DWD ICON computer model run is for 3pm on Tuesday 27th February. It shows snow showers affecting much of the UK, but local variations in conditions would be significant.

DWD ICON 00z, precipitation type, 15:00 GMT Tue 27th Feb

Daytime temperatures are forecast to remain close to 0C (32F) in much of the country but the midday sun is strengthening rapidly at this time of the year so there will be some thaw of lying snow when the clouds clear.

Blizzards pushing up from the south?

Computer models suggest snow showers will continue on Thursday and it could be the coldest day of the week. The details of what happens after are very uncertain but it looks like an area of low pressure will try to move up from the south. That could bring heavy and prolonged periods of snow but also an end to the freeze if it moves northwards across the UK and pushes away the cold block of air.

During the last 24 hours a split has developed between computer models.

Option 1. Milder from the south?

The American GFS / GEFS model is increasingly suggesting that low pressure will deepen and push northwards during Friday and the weekend. That initially brings a period of heavy snow but milder air steadily returns to southern and central regions. The GFS chart below is for midnight on Thursday. It shows the milder air indicated by green, yellow and orange shading approaching southern England. 

GFS 00z 850hPa, temperatures and thickness, 00:00 GMT Fri 2nd Mar

Option 2. Remaining bitterly cold?

The European ECMWF model suite supports a continuation of the very cold spell through next weekend and into the following week. The ECMWF chart below is also for midnight on Thursday. It shows the mild air associated with the low pressure area farther south and all of the UK remaining under the cold block. Thereafter the low pressure area fizzles and sinks southwards as the cold block reasserts itself.

ECM 00z 850hPa, temperatures and thickness, 00:00 GMT Fri 2nd Mar

Which outcome is most likely?

At this stage the TWO view is that the ECMWF solution will be nearer to the mark. However the milder GFS / GEFS scenario is only marginally less likely and is not discounted.

Summary

1) Unusually and possibly record breaking cold is expected during the first half of next week.

2) Snow showers become increasingly widespread with disruptive accumulations in places.

3) During the second half of the week an area of low pressure may push up from the southwest. That would bring the risk of blizzards but if it pushed far enough north milder air would begin to return.

Impact of the SSW

The increasing influence of high pressure and the possibility of cold blocks of air pushing across Europe during the rest of February and the first half of March could be a result of the Sudden Stratospheric Warming (SSW) event that recently took place. That raises the risk of cold weather in the UK during the rest of February and the first half of March. However it is not assured because high pressure blocks could align in a way that leaves the UK under a mild south or southwesterly air mass.

Check the latest snow forecast charts:

Meteo France Arpege

DWD ICON

NCEP GFS

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Forecast tools

Check the latest satellite images, computer model charts and rain radar:

1981 - 2010 daily temperature charts [NEW]

Temperature anomalies [NEW]

DWD ICON forecast charts [NEW]

EUMETSAT high resolution satellite images [NEW]

Rain and precipitation type radar

Meteo France Arpege forecast charts

Global Forecast System (GFS) forecast charts

16 day GEFS ensembles at a glance

By the start of next week it turns very cold and the risk of snow increases. Through the first week of March uncertainty grows with an increasing number of runs showing it turning milder. View latest GEFS.