While there is nothing that instructors, coaches or drop zone owners can do about the weather, the more students know and study these conditions and requirements the happier they will be.

There are few sports as weather-dependent as skydiving and it can be very frustrating to see a beautiful, blue-sky Saturday go by without one take off. It can be even more frustrating for students to watch experienced skydivers jump all day in winds from 16 mph to 20 mph, all getting nice soft landings and not be able to suit up and jump themselves.

So, the question heard most from students early in their progression is, "Can I jump today?" The answer to this question involves: visibility, cloud clearances, and wind velocities.

The winds aloft are important because students often wingload well below 1:1. For example a male student weighing 180 pounds with a 30 pound rig equals 210 pounds at exit. This student might easily be jumping a 260 square foot canopy. 1: .88. A female student weighing 110 pounds would exit at around 140. She would be jumping a 230 square foot canopy and wingloading at: 1:.61. If the winds aloft at 3,000 feet are 35 mph, both of these students could be backing up the entire canopy flight from opening to 2000 feet. The surface winds restriction of 14 to 16 mph protects students once they are under 2000 feet, usually, but winds aloft are often a mysterious aspect of the "no jump" rule for students. The link "How to Read a Winds Aloft Chart" at the bottom of this page gives the predictions used at most drop zones and well as a tutorial in how to to read the wind aloft charts. The link "How To Calculate a Jumprun" takes that knowledge and applies to the practical computations of "the spot."

The link "Accuweather" in the menu below in the daily "forecast details" offers a "wind gust" prediction for surface winds which is very useful. All of the links in the weather menu below are helpful.

Visibility and cloud clearance. Here is the standard USPA diagram for cloud clearances and visibility. At or above 10,000 feet MSL remember: 1-1-1-5 (111-5); below 10,000 feet MSL remember .5-2-1-3 (.521-3). If any of these requirements cannot be met, no skydiving.

Plus, there are the issues of instructor availability and the economics of drop zone operations. To put up an Otter we need the equivalent of ten seats sold for the flight. For a Cessna we need four. The Cessna is much easier to put up but it is not always the best option for Category A to Category C jumps, in my opinion, given that an Otter is also in the offing.

How to Read a Winds Aloft Chart | How to calculate a jumprun