Evaluating Weather for XC
This is the general process I’ve used for evaluating weather for XC flying in and around Bozeman, MT. The steps are generally as follows:
  1. Check wind at altitude.
    1. < 10 mph at 10,000 is perfect. If it’s higher, higher up (up to about 20 or so), then that could help with covering a long distance and getting good glides.
    2. Between 10 and 15 mph, I’m more cautious about it, especially if it is this high down low.
    3. 15-20 is generally a not condition I want to fly in.
  1. Top of lift
  1. XCSkies Pointcast!!!
  1. Cumulus cloud depth
  1. Cloud cover
  1. Airgram in Windy
The models I typically use:
  • GFS and ECMWF for 3-10 days out. Looking for low winds up high and little to no clouds.
  • HRRR for the day before and day of. Compare to NAM 3, NAM 12, ICON etc.
Let’s look at each of these steps in detail:

1. Checking wind at altitude.

2. Top of lift

3. XCSkies Pointcast!!!

4. Cumulus cloud depth

5. Cloud cover

6. Airgram in Windy