It is going to rain no matter what so just pack some rain proof/resistant clothing and equipment. As for thunderstorms, as of this morning when I was doing the forecast the chance for thunderstorms tomorrow was about 30% and for Friday about 40% but looking at the latest model runs, it looks a bit less. The only thing that will boost their probability even higher would be any breakages in the clouds that would let heating from the sun occur to generate increased instability. But like others have said, go for a hike but aim for something keeping you in the trees or know how to head down (or up if your closer) to avoid being struck. If you hear thunder, the storm is 10SM or less (depending on dampening effects of trees or weather occuring before the storm). Timing though depends on how fast they are approaching. Some take hours to move 10 miles while other times I have been working up top and seen them move in a matter of minutes. Some statistics from NOAA: In 2008 of the 28 people that died nationwide, 100% of fatalaties were outdoors, 79% were males, 36% were males 20-25 yrs in age, 32% were under a tree, and 29% on the water. While 28 is low when normal is 62, think of how many millions are still alive and kicken. You are statistically more likely to die traveling to your hike than getting struck while on your hike. In long term studies it has been found that golfers, boaters, or people in urban parks have a much higher percentage of being struck than a hiker. I am not encouraging wreckless behavior, but I go hiking if thunderstorms are just a chance, the only time I wont go is if the forecast says they are likely or 100% chance. But if live near the Whites, plan on a different day/weekend if you still feel uncertain. The Whites will be here another day.
Last edited by Knapper; 06-10-2009 at 08:59 PM.
Staff Meteorologist/Night Observer, KMWN (Mt Washington Obs., NH)