Forecast along your route

Pick where you start, where you stop and where you are going, or draw the way on the map. Set when you leave and how fast you drive, and the National Weather Service forecast is read for every 10 miles of the trip at the hour you will be there, with any warning or advisory in force at that place and time.

How it works

The route is not a road route. No free routing service allows a site like this one to use it, so the trip is drawn as straight legs between the places you pick, each the shortest line over the earth, or as the line you draw yourself. Roads wind, so the clock is run on the straight distance stretched by a fifth, which is about how much longer US highway trips are than the straight line between their ends. Draw the way yourself for a trip that bends around mountains or water.

Along that line a point is taken every 10 miles, fewer on a long trip (at most 60), and each is given the time you would reach it at your speed, with the stops you add. For each point the forecast is the NWS hourly forecast for its 2.5 km grid cell at that hour: the words, temperature, wind and gusts, the chance of rain and how much, snow, sky cover and visibility, and every alert in force there then.

The NWS grid reaches about seven days ahead; a point you reach later than that has no forecast and says so. Outside the United States the planner has no alerts to join, so points there are left out.