I have just read the fell top assessor's report from Tue 18/12/18. Interesting that even his waterproof did not keep the rain out. Here is the text from the report.
"A wild day to be trying to climb a mountain. The assessor chose to attempt an ascent of Helvellyn via the Wythburn Path, as it is straightforward with no big crags to get blown off. In the event he gave up his attempt at 850m on the western flank of Nethermost Pike due to constantly being hurled to the ground by the gale to storm force winds. Quite often in winter the best decision is to turn back. Today was definitely one of those days.
Torrential rain was the other main weather feature today, filling becks and making all ground waterlogged. Despite the thorough wetting everything was getting, including the assessor right down to his base-layers, there was still some ice present on the paths above 750m, although as the thaw continues throughout the day it is impossible to say how much ice will be present on the high fells tomorrow.
Anyone heading onto the fells today should really have chosen a lower level route instead. Double waterproofs might have proved useful, along with lots of warmth layers, and the usual map and compass, food and drink. An ice axe and crampons should always be carried in winter on the high fells, but today they weren't used."
Perhaps having two waterproofs is the answer?