Chicago Area Skydiving Weather
Skydiving centers make every attempt to operate safely, even when those decisions negatively impact the bottom-line. One injury or bad experience is a million-fold worse than none. A common saying in the sport is:
"It is better to be on the ground wishing you were in the air, than to be in the air wishing you were on the ground."
Skydiving is a weather dependent sport. All skydiving centers and licensed skydivers must comply with Federal Aviation Administration (FAA) Federal Aviation Regulations (FARs).
FAR 105.17: Flight Visibility and Clearance from Cloud Requirements (for parachute operations) states:
No person may conduct a parachute operation, and no pilot in command of an aircraft may allow a parachute operation to be conducted from that aircraft--
(a) Into or through a cloud, or
(b) When flight visibility or the distance from any cloud is less than prescribed in the following table:
Altitude Flight Visibility (statute miles) Distance from clouds
1,200 feet or less AGL 3 500' below, 1000' above, 2000' horizontal
>1200' AGL and <10,000' MSL 3 500' below, 1000' above, 2000' horizontal
>1200' AGL and >10,000' MSL 5 1000' below, 1000' above, 1 mile horizontal
Note: AGL means above ground level; MSL means above sea level
These rules are in place for safety reasons. If we are inside or too close to a cloud, it may be impossible for an aircraft to see or avoid us.
Skydiving centers also consider other meteorological conditions, which are not expressly ruled by the FARs. Most skydiving centers will not operate in rainy conditions, even if the cloud clearance and visibilty meet the FAR minimums. Most skydiving center will not operate when there is lightning within 20 miles of the field.
Many skydiving centers also self-impose wind limits for their operations. The USPA (United States Parachute Association) does not have established wind limits for normal parachute operations (there are wind limits for solo student training and exhibition jumping). Most parachutes have a forward speed of about 25 MPH, and many skydiving centers do not operate if the ground winds exceed that. They also do not operate when winds aloft (especially those at parachute flight altitudes) exceed 40 MPH (where the parachute will be travelling 15 MPH backwards across the ground).
Other considerations are also made for factors like turbulence (even when the wind speed is not at or near the limits of the skydiving center). Two types of turbulence can affect parachute operations: Mechanical turbulence and clean air turbulence.
Mechanical turbulence is a situation where winds pass over an object, such as trees or buildings. On the downwind side of the object, the air is very unstable and can lead to canopy collapses and downdrafts (both of which can result in severe injury or worse). Clean air turbulence is not as predictable, but can be just as dangerous.
Clean air turbulence can be a result of thermal activity, strong updrafts or downdrafts, or windshear (wind layers going different directions at different altitudes).
Your skydiving center of choice monitors and assesses the weather continuously, but are not weather experts. They cannot accurately predict the weather. They should however, give you honest information about current conditions, and maybe even an opinion about the weather for the day.