I use a pair of Time RXS Rain gloves, and I absolutely swear by them. They wetter it gets, the better they grip. They don't get sticky/tacky, but somehow I don't have any slipping issues ever.
Your post reminded me that I want another pair, and it looks like them might be discontinued? Anyway, if you do see a pair, my advice would be to buy them. They aren't waterproof like dishwashing gloves, but I've yet to find a pair of rain gloves that is even close in my opinion. (The leather is buttery soft and has stayed that way for a full year... they are very high class)
They seem to come in a "Winter" configuration with some insulation as well as the same leather surface as the "Rain" gloves, those might work well. Since the rain gloves aren't insulated, I don't wear them in temps lower than 40.
The best glove I've found for cold, wet days cooler than 45 is the Castelli Dilluvio... They feel like a fortress on the hands. The pebbly surface keeps the grip working decently, and the gloves are completely impenetrable. With a pair of mechanics gloves as liners I'd ride these down to about 15F.
FWIW, I took these two pair of gloves to our January and February training camps in the san juan islands (puget sound) and they were perfect for the exact conditions you describe - 30s-50s and rain