The light rain of yesterday has made little if any difference to the river. It should be fishable all the way.
There's more drizzle or light rain forecast for today but it's unlikely to have any effect on the river.
The link below gets you to EA's river level at Musgrave - save it to your favourites and I'm redundant!!
http://www.environment-agency.gov.uk/homeandleisure/floods/riverlevels/120711.aspx?stationId=5059