2. Macro Weather, Glider Hookin
This is the 2nd article in a series of columns that will review step by step concepts concerning weather and flying pointers. Get together with your local instructor and club to discuss these topics in greater detail. Be sure and expand your library of books and videos. This column will recommend certain books and videos, realize that there may be some ideas that are arguable. Practice the weather concepts daily, even when you aren't going flying. Begin to identify the trends that make for the best coastal flying, thermal conditions or exhaust heat sessions. Give your chums a call who flew on days you couldn't and see how close you can get to predicting the conditions. Be thoughtful about going to new areas and how powerful some atmospheric influences may be in contrast to your home sites. There are some sites that become unruly by 9am in August yet others that can be flown all day. Remember - Practice is the Mother of Skill!!
Approaching "lows" and "highs" have powerful effects on the stability of the atmosphere and the wind intensity and direction. Be watchful of your barometer, information sources and the sky for evidence of a low. The low is basically a "puddle" of cool air descending from the poles into a warmer area which is the "high". Weather maps indicate low pressure zones very clearly with an arced line with dangling triangles. The fine gray lines surrounding the "lows" and "highs" (isobars) indicate how steeply the pressure is dropping. Tightly spaced isobars, let's say every 100 miles, generally indicate a high probability of regional wind flow. So, a weather map showing the jet stream over your area, a "low" and tightly spaced isobars isn't promising. Study the weather maps for a couple of days and you'll quickly notice how systems generally move and be able to anticipate the flying conditions.
If a "low" is approaching over night or early in the morning, you may notice earlier thermal activity. This is because the decreasing pressure and lower upper atmosphere temperatures allows thermals to release easier, particularly with direct sunlight. In the scenario of a "low" approaching late in the day, where you've had heating throughout the day, you may notice a thickening cirrus layer of clouds and that your barometer is on the decline. With this late day "low" you may notice more demanding and erratic thermals and strong windy conditions on the ground. The arrival of midday to late afternoon "low" can be of concern to pilots in some areas of the country because conditions can become very intense. In general, the approach of a low will bring winds from the Southwest.
Pilots looking for soft and easy conditions will find some "lows" where the flying is just fine. When a "low" is slow moving, without compressed isobars, there may not be much regional wind flow. If there isn't much solar heating of the ground the air may be very pleasant, but be aware that even a few minutes of sunlight can start the thermals releasing. Be cautious with a "low" that a storm cell can develop and may create strong lift, sink or gust fronts. A thick mid level (stratus) layer of clouds may keep down the solar heating, but it can hide a towering cu nim (cumulous nimbus - raincloud).
As the "high" builds you may notice winds on the surface, and at altitude, more from the Northeast. The jet stream will most likely be far away, to the North is best, and the isobars will spread apart to over 300 miles between each gray line on the weather map. With the increase in pressure and warming of the upper atmosphere you should notice thermals taking much longer to develop and with ever increasing pressure tighter and more sharply edged thermals once they do release. Many pilots fly during "high" pressure systems as the conditions tend to be more predictable. You'll find anabatic flow up East facing slopes in the mornings that can be very user friendly, to a point. Be aware that thermals are ever building and that a heated area (puddle) reaching just the right temperature will suddenly release its power. If you choose to fly as trigger temperature is reached you may need refined glider management skills in pitch and roll control, and be aware that landing zone conditions can be very unpredictable as thermals lift off and change the localized wind flow directions. Keep in mind that thermals will develop and release earlier in the morning in the Summer than in the Winter as a result of more or less sun exposure.
Facing forward while attached to a paraglider is very risky in anything other than completely "soft" conditions. Hooking-in to a paraglider while facing forward in "sporty" conditions can lead to a loss of control very quickly, thus damaging you or your glider. Since most launches are reverse launches, you should hook-in already facing the glider in the reverse position. Even if you plan to do a forward/front launch you may consider making this your hook-in procedure for safety reasons. If you decide you need to duck under your lines be sure and make a healthy bridge of lines using 2 hands so that you don't accidentally turn without a line in hand, or drop some of the lines around your neck.
The reverse position hook-in technique is actually pretty simple. First, a right handed pilot should rotate left, or counter clockwise, from a reverse position and vice-versa if left handed. This will prepare you for doing reverse tandem launches without accidentally knocking open the reserve during the rotation. A pilot with 500 launches looking into doing tandem flight is going to be frustrated by re-learning a different rotation out of the reverse position, so you might as well learn this from the beginning. You're probably thinking that you'll never do tandems flights, but since you can't be sure, you might as well develop the right skills as soon as possible.
While facing the glider shake out the risers so that the lines are clear. Be sure and check for any snags or knots and lay your glider in a horseshoe shape in light wind or a symmetrical rosette if windy, be sure and pull out the tips so you don't get a line caught. The A riser should be on top, facing upward, with no twists. A right handed person will then twist both of the risers 180 degrees to the left, counter clock-wise, the A will now be facing the ground. Put tension on the biner and make sure it isn't twisted. Attach the risers to the biners so that they are crossed with the riser going to the pilot's left hip on top. To double check the configuration pull on each riser so that the tension will prove that the "A" faces away, away from the pilot, and the "rear" faces near, towards the pilot, - all without any twists. The accelerator line is easily attached by bringing it from the harness pulley in a direct path to the riser attachment point.
Head to the local park and give this method of hooking-in a try for 10 perfect repetitions. Try this with the glider in a rosette as well, you'll be surprised how easy it is to see that your lines are clear, despite the glider being rosetted. Remember that you're trying to avoid facing forward while attached to your glider, so learn to do this so you aren't compelled to rotate duck around and face forward to see if you got it right.
My next article in this series will discuss localized upper level atmosphere information and how to perfect the reverse launch. The videos "Starting Paragliding" , and "Weather to Fly" are my favorites, of course. You should read Whittal's "Paragliding: the Complete Guide" and Pagen's "Understanding the Weather". When reading Pagen's book you may want to try learning a new concept a day from the list of items in the glossary. Check the index for Isobars and Pressure systems to help further your understanding of the discussions in this column.