Pembrokeshire County Council has sent extra snow ploughs and a snow blower to the Crymych area to keep main routes open.
Snow that fell last week is now drifting off the Preselis in today's strong winds, causing traffic chaos and school disruption.
The B4329 Haverfordwest to Cardigan road has been blocked by drifting snow over the mountain top between Brynberian and New Inn.
Snow has blown through field gates and onto the roadway. Some cars have been abandoned in drifts.
As this road cannot yet be ploughed , road closed signs have been placed.
Drifting snow is causing problems in places on the A487 between Fishguard and Cardigan and the A478 berween Penblewin and Cardigan . There are reports of vehicles trapped in drifts at Efailwen and Glandy Cross, but snow ploughs are keeping the road passable.
New Inn to Llanychaer road is impassable in places between New Inn and Morvil. Some cars have been abandoned in drifts.
There area also four ro five foot drifts on the Crymych to Mynachlogddu road.
Ysgol Preseli (Crymych) School closed at 12pm; Maenclochog School at 11:30am, Ysgol Clydau closed this morning and Eglwyswrw school is closing at 1pm.
Snow ploughs are also working on the A4139 between Tenby and Jameston, where trees have been reportedly blown down near Lydstep.
A snow blower in action in Tegryn on Tuesday. Video taken by Rhys Bowen.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here