|County Championship Group Three, Headingley (day three):|
|Glamorgan 330: Van der Gugten 85* & 161-4: B Root 77*, C Cooke 57*; Coad 3-18|
|Yorkshire 193: Lyth 53; Taylor 2-16|
|Glamorgan (6 pts) lead Yorkshire (3 pts) by 298 runs|
Glamorgan's hopes of a surprise win over County Championship Group Three favourites Yorkshire were hit by the weather, after snow and sleet cut the third day to just one session.
Glamorgan go into day four on 161-4, an imposing lead of 298 runs.
Billy Root (77 not out) and Chris Cooke (a patient 57 not out) added a further 93 in the opening session.
Yorkshire's attack was two men down with Ben Coad (pec) and Matthew Fisher (abdominal injury) off the field.
Root has had the better of older brother and England captain Joe so far, scoring 120 runs for once out.
But the ground could not recover from 90 minutes of snow and sleet, leaving Headingley under a wintry white blanket.
Glamorgan may need to declare early on the final day on Sunday to stand a chance of forcing victory.
Yorkshire coach Andrew Gale:
"We're behind in the game anyway, but when you lose two seamers it's always going to be tough.
"Had we had Ben Coad running down the hill early this morning, a couple of quick wickets and you never know - but we're certainly up against it now.
"It's frustrating and a massive blow. They've got a history of injuries. It's something we reviewed at the end of last season as to how we were going to get them fit and on the park.
"It has almost been a forensic investigation into it. We've measured every ball they've bowled, and at what intensity. We've got the scientists involved and everything."
Glamorgan assistant coach David Harrison told BBC Sport Wales:
"That's a first for me. We played at Derby five years ago when we had a hailstorm but I've not seen a full-on snowstorm cause the end of a day's play before.
"It's a shame because we had a really good first session and were looking forward to pushing on and trying to extend our lead.
"Billy Root has been great since he joined us a couple of years ago. His form has been really consistent. He's had a really good game against Joe in a bit of a side-plot, batted really well and nearly got Joe out.
"Hopefully the weather holds. We'll have a chat about what to do in the morning but we've played really well in this game against a strong Yorkshire team."