The Met Office has this afternoon upgraded a snow warning for Sheffield.
WEATHER WARNING: Tuesday's hour-by-hour snow forecast for Sheffield
There is now an amber warning in place for much of Yorkshire for Tuesday.
An amber warning is the second highest level on the Met Office's scale.
How the cold weather could affect your mobile phone
The latest warning states: "Snow showers or longer periods of snow are expected on Tuesday, accompanied by very low temperatures.
"The heaviest, most persistent snow looks likely to cross the area during the morning - the focus has been adjusted northwards to take into account latest ideas, removing Lincolnshire but adding more of Yorkshire and areas towards Manchester, Teesside, Durham and Newcastle.
"There is the likelihood of travel delays on roads, with some stranded vehicles and passengers, as well as delays or cancellations to rail and air travel.
"Some rural communities could become cut off. Power cuts may also occur and other services, such as mobile phones, may be affected."
Between four and six inches of snow are possible.