The Polar blast will plunge downwards through the United Kingdom later on Thursday when the remnants of Storm Caroline clear the United Kingdom and this will signal an onslaught of bitter weather, including snow, sleet and frost.
High winds are expected to affect northern Scotland on Thursday.
Met Office predictions don't now show snow for London on Monday as their forecast doesn't quite go that far.
A yellow "be aware" weather warning is in place for the region, which runs from 8am on Thursday until just before midnight.
Roads, railways and ferries are all expected to be disrupted as gusts of 70mph to 80mph are hit northern Scotland, increasing to 90mph in exposed areas.
"Flying debris is likely and could lead to injuries or danger to life", the Met Office warned.
"This will develop a cold northerly flow and as a result will drag cold Arctic air in across Britain late Thursday overnight into Friday resulting in a sharp drop in temperatures".
Forecasting snow showers in the United Kingdom can be quite challenging as conditions are often borderline between rain and snow.
A Met Office spokeswoman, Nicola Maxey, said: "Winds will pick up across the rest of the country so it will be a blustery day for many areas". Some short term loss of power and other services is possible.
"North and northwest counties will be most at risk, as well as higher ground elsewhere".
Winds are forecast to strengthen across parts of Britain on Wednesday ahead of the arrival of Storm Caroline.
The snow-ice warning of Ireland will last well into Thursday afternoon and will be renewed briefly come nightfall until Friday at 4pm.
Coastal routes, seafronts and coastal communities are likely to be affected by spray or large waves.