since i went mainly WFP 2 and a half years ago i work far more in rain/showers than i did when i was trad only.the problem with trad when raining is wet ladders and roofs you have to stand on,mossy flags,wet decking,imprinted concrete etc.
AND if its raining on the window you can leave marks when you ve finished squeegeeing due to the soap mixing with the rain water!!you can get away with it to a certain degree as long as you use plenty of dry cloths for detailing/buffing.
i know i prefer WFP in the rain!
saying that it was torrential rain here in the north west from dinnertime so early finish for me!
better luck tomorrow!!
dazmond