Summer is upon us and with it comes the inevitable thunderstorm. This is especially true in the Southeast where the forecast for “vicinity thunderstorms” dominates nearly every TAF. Thunderstorms don’t always have to spell out a cancelled flight, but proper thunderstorm avoidance requires a heightened level of awareness from us as pilots.
The safest way to avoid a thunderstorm is to simply not fly. Pretty boring if you ask me, and not to mention inconvenient. Unfortunately, waiting it out will usually be your only option, especially in smaller airplanes. I wish I could quantify the go/no-go decision in some way, but I can’t. It all depends on your personal experience as a pilot, the severity and proximity of the weather, and the type of airplane you intend to fly. If there is any question in your mind, forget about flying and spend some quality time with other grounded aviators. Thunderstorms are nothing to play around with.
That being said, we can’t let a little thing like scattered thunderstorms cancel our plans all the time. Scattered cumulonimbus clouds tend to be few and far apart, making it easy pilots to pick their way around the weather. There are two schools of thought on this.
A lot of VFR pilots prefer to stay down low and avoid the rain shafts by a healthy margin. Although this method does work, it has its drawbacks. First off, it’s mighty bumpy down low with all that convective activity going on. Furthermore, a thick haze layer could obstruct your vision just enough to lure you into the weather. Flying around under the clouds with increasing weather can even tempt the most disciplined pilot into scud-running, which is always a bad idea.
Perhaps the best way to dodge weather is to get on top and visually weave your aircraft around the buildups. After flying a variety of aircraft with anything from onboard radar to XM satellite weather, I can personally vouch for Richard L. Collins’ statement that the best weather avoidance tools are your own eyes, or the “Mark II Eyeball,” as he calls it.
Visually dodging works great, but piston driven (and even turboprop) aircraft can’t always stay out of the muck. That’s right, the instrument rated pilot might find himself blindly flying towards embedded thunderstorms! Without onboard weather radar, this is a very dicey proposition and serious thought should be given to landing and reevaluating your options.
If you are continuing (are you sure this is such a good idea?) then it would be prudent to make full use of air traffic control and local flight service stations. You might be blind, but the controllers and FSS personnel may be able to suggest alternate routing that will keep you out of the worst of it. Sure, there are no guarantees, but it’s better than nothing.
Even in the clouds, the window can play a role in thunderstorm avoidance. Near nasty weather, it is not uncommon to see gradients of white and grey in the windshield. As a rule of thumb, avoid the dark patches for the smoothest ride and don’t ask, but tell the controllers what you need in terms of heading and altitude.
Thunderstorms are serious business, and ought to be avoided at all costs. This doesn’t mean that you can’t fly, but it does mean that you have to be careful. Visual avoidance is always your best bet, and the decision to enter a region of thunderstorms in IMC needs to be well thought out. Use all available resources to plan and reevaluate your flight, and know that there is no shame in landing and waiting out the storm.