I find the following sites extremely useful when planning hikes:
Weather – I find this to be the most reliable, accurate weather source for the White Mountains. That being said the weather systems in the White Mountains are extremely complex and can change quickly. Preparation with your gear and not being afraid to turn around cannot be understated! The mountains will be there tomorrow, make smart choices and so will you!
https://www.mountain-forecast.com/
Trail Conditions – this one is more widely used and arguably more important in the fall, winter & spring but still good to check out to see if anyone has hiked the same trials a day or two earlier to see if there are any major obstacles (trees, water crossings, difficult scrambles, etc.) and if someone recommends using spikes, snowshoes, etc. But again, use your own judgement based on the conditions of the particular day you are hiking. Use this as a loose guide. Trail reports have a short shelf life and become obsolete 3-4 days after they are posted.
https://newenglandtrailconditions.com/nh/
Also buy these books and map – they are gospel!
Woods Wanderers 