The Long Mynd has seen some rain in the last few days as has most of the U.K. We went on the shop ride last night, to our surprise the trails are all still running fast (surface water). The Long Mynd as a whole drains very well and we tend not to get much mud.
Light weight waterproof jackets, front mudguard and some glasses will be ideal in these conditions. Keep the spray down and keep good visibility. Plenty of traction out there so not really any need for crazy mud spikes.
For day to day updates you can call the shop on 01694 781515.