Originally Posted by Sparrow
One other question now that I think of it. What is the best source for weather info? I've been looking at https://www.mountain-forecast.com/peaks/Mount-Whitney/forecasts/4418 but not sure if you guys had a more preferred source. Definitely don't want to get up high only to realize its a stormy day.
I also used the weather.gov site: https://forecast.weather.gov/MapCli...rine=0&unit=0&lg=en#.XxyKjZ5KjIU

and the various model runs at: https://weather.us/model-charts/standard
and: https://weather.us/model-charts/euro

You want to check the trend and consistency. If all of those sites forecast clear skies and 0% chance of precipitation for the day of your hike and the day before and after, you're good and can safely summit at any time of the day. If the forecasts conflict, consider an early start and turn around when you see clouds start to build. A few small isolated clouds can turn into rain and thunder in 2 hours or less.

FWIW, on my July 20 summit, Mountain Forecast predicted clear skies in the AM, some clouds in the PM, and calm winds. The actual weather was clear skies from 6-9 AM, cloudy by noon, light rain showers and some thunder in the afternoon (not intense or very near), breezy conditions from 4 - 5 PM, and clear skies and calm winds after 6 PM.

Also, Mountain Forecast usually underestimates high temps and overestimates low temps. The diurnal temperature variation is typically greater than what Mountain Forecast predicts.