Written with AI assistance and may contain mistakes. Verify against the official Transport Canada publications before relying on anything here.
Veer and back, with height and time of day
| Term |
Direction turns |
Example |
| Veer |
Clockwise |
240° → 300° |
| Back |
Counterclockwise |
300° → 240° |
| Factor |
Case |
Direction |
Wind speed |
| Height |
Climbing |
Veers |
Strengthens |
| Height |
Descending to surface |
Backs |
Decreases |
| Time of day |
Day |
Veers |
Stronger, gustier; usually strongest in afternoon |
| Time of day |
Night |
Backs |
Lighter |
- Height rows: Northern Hemisphere. Climbing: friction fades, wind turns toward isobar-parallel, faster (PHAK ch.12, above 2,000 ft).
- Height, descending to surface: wind backs and decreases (TP 13014 sample exam item 57).
- Time of day rows: speed is surface wind (TP 13014 sample exam item 58; afternoon peak NOT-IN-SOURCE locally).
- Day: daytime heating mixes faster air down from aloft.
Trap: veer is clockwise, back is counterclockwise.
References
- Veer with height: derived from AWH 10.5 and PHAK ch.12 (wind turns toward parallel to isobars with height); TP 13014 sample exam items 57 and 58 (veer/back, day/night); afternoon peak NOT-IN-SOURCE locally
Practice