David,
The skiing that's closest to Madrid, is, well, a bit crappy. It depends really on the year- but since its so close, when it snows everyone goes, and unless you're up at the butt crack of dawn, chances are that by noon the snow will be stripped. But again, it depends on the year... but mostly it is a bit overcrowded. HOWEVER!!!! There is good news! ANd that there are a couple of other skiing places not far from Madrid (but nowhere you'll be driving to for the day! We're talking a weekend trip here) that are bigger, and have better skiing.