This is a page on how to read the weather, gather resources, and determine the appropriate conditions to fly. For wind and weather recommendations for specific sites, see Flying sites.
LIVE WEATHER
Wind meters (also called “wind talkers” in 🇿🇦 ) are small, solar-powered weather stations that report actual current weather conditions. This tells you what conditions are at that moment (good to compare with the forecast, RASP models, and institutional knowledge like, such as “don’t think about flying when the talker at such-and-such site shows >25km/h”).
Add these websites on your phone (you can do so on Android or iOS) or download the relevant apps to check actual conditions from the hill or the sky. Write down the predicted and actual wind speeds and other weather conditions after flying a site to find your personal sweet spot and plan better for future flights.
Webcams
These are good to check for cloud cover, or maybe if other pilots are in the air:
- Table Mountain panoramic webcam (good to see TM, LH, the Apostles, and Sigs; fun to create timelapses)
- Vanilla Streams (Sea Point, Three Anchor Bay, Table Mountain)
Ask seasoned pilots
As a beginner or a visitor to a new site, it’s a little intimidating to find out the sweet spot between a mediocre and a dangerous day for flying. Join a social media group (there is an endless amount on WhatsApp / Facebook) and observe (or ask). Most pilots are very happy to share their thoughts.
For South Africa (but specifically Cape Town and the surrounding area), join the South African Paragliding community on Whatsapp. There are sub-groups for Cape Town, Wilderness, the Garden Route, even specific tricky sites like Lion’s Head.
Also, please don’t be selfish/lazy and ask something like: “Where can I fly tomorrow?” (then you’re just giving your homework to other people). Rather say: “I looked at the surface winds, the winds at elevation, the temperature, and the rain forecast, and I think that site X might work tomorrow for reasons Y and Z. I’d appreciate it if you can tell me if I’m completely wrong here, missed something, or if anyone has other input.”
Below is how I plan for an upcoming flight, starting about three or four days early.
Surface wind and gusts
You need to safely launch and land, so this is a good place to start.
- SkySight. This has fast become the best PG XC planning tool, and the wind forecasts have been very reliable.
- I use Windy and monitor it until the moment of launching (and sometimes during my flight if my flight plan changes). It has four models (ECMWF, GFS, IKON, Meteoblu) to choose from. I find GFS and ECMWF to be slightly more reliable. It has a notification feature (where it sends you a message: “Wind forecast to be 8-12kmh E at such-and-such location”)
- 🇿🇦 RASP (The South African Regional Atmospheric Soaring Prediction) shows the surface wind and often will be more accurate about things like incoming afternoon gusts than Windy. It’s most accurate for the next day’s flying (updated 6 pm, SA time) and on the actual day of flying.
Wind and gusts at elevation
Wind speed, gusts, and direction can be significantly different at different altitudes. SkySight, Windy, and RASP (and other sounding forecasts) allow you to see the predicted wind at elevation. No good taking off in good wind and then getting blown over the mountain after you’ve gained 200 metres in elevation.
Wind at altitude with Windy
On Windy, select the date and time of your planned flight. Move to the area and select (right-click on web, tap and hold on the mobile app) “Show weather picker”. Then use the slider to see what the wind is going to do at higher elevations: https://community.windy.com/topic/12172/reading-wind-and-gusts-at-different-altitudes.
Wind at altutide with sounding / Skew-T / RASP
(A deeper dive on sounding charts, further down)
The wind barbs on the right-hand side of sounding graphs have all the information you need. The long line (“flagpole” or “vector”) shows you the wind direction, other lines show the wind speed: short lines mean 5 knots (9.3 km/h), longer ones 10 knots (18.5 km/h), triangular ones 50 knots (93 km/h), or a combination thereof.
Note that some sounding charts will indicate altitude in pressure — hPa (hecto Pascal) or millibars– others in feet, others in metres, etc. Just convert these as needed.
Precipitation
Paragliders sink, spin, and stall very easily when wet, so rain means no flying, go read or watch some paragliding videos instead.
Some clouds are great for flying, others are very bad, and others are neither good nor bad. Learn to identify them.
I use a combination of SkySight, Windy (the Basic forecast and Airgram views), RASP, and yr.no to predict cloud cover and the probability of rain.
Sounding / Skew-T
Learn to interpret these diagrams, they’re probably the most important and useful out of the lot. They show you a multitude of information about the sky above you in one image, including:
- temperature and dew point
- wind speed and direction
- instability (good) and inversions (bad)
- cloud base and more
It will help you immensely in understanding what may make a good or a bad flying day and understand what’s going on in the sky. I won’t try to re-do a lesson here, just watch/read the ones below:
- YouTube: Sounding on Windy.
- YouTube: Kelly Farina – Rough Guide to Skew T (multiple parts, watch them all).
- YouTube: Spotting good XC days
- YouTube: Greg Hamerton – The Cloud Engine
- YouTube: How to read a Skew-T Chart – for Soaring Pilots
- YouTube: How to interpret atmospheric soundings
- Dr Jack: BASIC Thermal Forecast Parameters
Flight-planning apps
In addition to the weather forecasting apps/sites mentioned, you should subscribe and learn how to use these, especially if you plan on doing XC flying since they show forecasts over some time and distance:
More thoughts
- A good day to fly? Go fly!
- Is the wind a little strong? Find a place to practice ground handling (an hour on the ground = ten in the sky). See: Manoeuvres
- Is it raining or is the wind too strong to ground handle? Watch videos, read books/articles, listen to podcasts, and study meteorology.
