This has been slowly bubbling and evolving the last few days (actually up to a week or more) and is finally in to a time frame now that is quite reliable.
From Thursday evening a cold continental airflow is set to quickly become established over the country. The first effect of this will be seen Thursday night with a severe frost particularly in the northwest but across the country inland as well.
Then from Friday for the weekend it's looking increasingly likely that some wintry showers and snow showers will start effecting eastern coastal counties in a northeasterly wind as well as far northwestern counties. Temperatures looking set to be getting very low at that stage, not rising above 2 or 3c in the east generally by day but the real effect is at night. I can see a few -6 or -7c around at least inland. So expect some cold weather warnings.
There will almost certainly be accumulated snow on higher routes in the east, hard to tell at lower elevations right now (although the wind won't be strong and this would favor the possibility at coastal margins likely to be most effected) as this has still some evolving to do on the models.
But it's a safe enough call for the weekend now. Increasingly cold, wintry showers and then some snow showers for eastern areas. Alternating winds between easterly and northeasterly. Frost and Ice around as well.
This could be a longer term cold period well beyond the weekend with differing scenarios as well but not much confidence at that range so do keep informed!
Once the models firm up on the scenario i'll edit the OP with relevant charts. It's minor details need to be firmed up on for the weekend.