I typically check the below sites when planning a trip to get an idea of what the weather might be, and use that to help me pack or change objectives. While the forecasting can be really good at times, it’s important to remember that these are just forecasts, and being prepared for them to be wrong is part of the game. Some people choose to check the forecast on their iPhone for the nearest city to their objective, and not to obsess over the fine details of the weather. Personally, I like to have the best possible idea of the chance/volume of precipitation and temperatures for a given trip. I usually look at 2-3 of the below resources and try to cross reference the data to make a decision about where to go, and what to bring.
Mountain Forecast: One of the first forecasts I check when considering a trip to a specific peak. Mountain Forecast is easy to read, and updated twice daily. Forecasts for several elevation bands are available which is helpful if you’re planning a multi-day ascent. This site tends to be optimistic for fair weather, so don’t ditch the Gore-tex until you cross reference this forecast with the others listed below. Mountain Forecast also provides a freezing level, which can be useful for deciding where to camp, if floatation is advisable, and high mountain snow stability.
Meteo Blue: A great forecast on it’s own, I use this site specifically for it’s Multi-Model feature (found on the left side navigation bar). This feature shows the results from several models graphically, which illustrates forecast reliability. When most models agree, I feel better about trusting the forecast. Conversely, when the models are all over the place i’ll take the forecast with a grain of salt and prepare for the weather predicted by worst forecast model. I mostly use this site to determine the reliability of the forecast.
NOAA: The National Oceanic and Atmospheric Administration is no doubt, a very powerful tool for determining weather for an upcoming trip. Using this tool properly requires a some attention to detail and a little know-how to get the best data.
The common mistake is to type “Noaa Mt. Baker”into google, and then to work from that forecast alone without further investigation. The forecast can vary depending on which search result link is clicked. When using NOAA, it is important to pay attention to the green map in the lower right hand side of the main forecast page. The darker green square within the map indicates which specific area is being forecasted. Occasionally the google search result will not be pinpointed on the intended area. In the below screenshots it is shown that the forecast being provided is for Mount Baker (the peak, not the ski area) at 10,072 feet. Notice the map on the right selects the west side of baker at 5,676 feet.
Additionally, at the bottom of the main forecast page, one can choose to look at the Hourly Forecast, a hour by hour forecast that spans 48 hours and provides specifics on Precip, Temperature Wind Speed, Lightning Potential and other factors. The Zone Area Forecast will provide a broad regional forecast and snow levels (Note: Not freezing Levels).
Climbing Weather: I use this more in the context of Cragging than anything else. While this site does provide forecasts for some of the Cascade Volcanoes, it doesn’t show the elevation for the forecast, nor does it allow the user to change elevation bands. The best feature is the “Areas by State” page, by clicking the name of the state, one can scroll through all the listed areas and get a snapshot of which of them might be dry. I’ve found these forecasts to be pretty reliable, the forecasts typically agree with NOAA. In sum, if I have the day off and can’t decide where to go get on dry rock, this is my first resource.
Cliff Mass Weather Blog: Usually specific to the PNW, Cliff mass writes a fantastic weather blog. Often he will publish articles about upcoming obscure weather events, seasonal forecasts, record breaking weather, and climate change. I’ll peruse his blog about once a week for entertainment or to dig into the science pertaining to unusual weather patterns (such as “when is this rain going to stop finally!?”).