I can't speak for anyone else, but I like Accuweather. The problem is that weather can be fickle this time of year. A couple days ago it was predicted to be in the high 80s on Saturday. Today it looks like the heat was pushed back a couple of days. Right now Accuweather predicts "cloudy with a little rain in the afternoon" on Friday Nov 14. Saturday Nov 15 is "thick cloud cover." Sunday Nov 16 is "Brilliant sunshine" and Monday Nov 17 is "Cloudy; a little morning rain followed by a shower in spots in the afternoon." I would wait until a couple of days before your trip and see if the prediction has changed.
As far as what to pack - bring layers. You'll probably wear tshirts during the day and sweatshirts in the evening. If you plan on buying clothing as souvenirs, take that into account.