The internet and mobile apps have changed life for billions of people around the world, and pilots are certainly no exception. Some call it a technological liberation, others call it a democratization of information, but the end result is the same: all of us have instant access to information that was once either unavailable or jealously guarded by experts.
While this has undeniably been a positive development, it doesn’t come without risks. If we’re not careful, more information can actually lead to less knowledge. Just spend 10 minutes on Twitter if you need proof – everyone there is an expert on politics, economics, sports, science and so much else. This chaos shows that it may be easier to find the right answer online, but it’s also easier to find only the answer you’re looking for. Confirmation bias runs rampant when information is plentiful.
The familiar ritual of a preflight weather briefing can easily fall into the same trap. Where once a preflight weather briefer (in person at a Flight Service Station – how quaint!) sorted through all the information and offered a stern warning that “VFR flight is not recommended,” the go/no-go decision now rests squarely on our shoulders.
I don’t mourn the disappearance of FSS briefings one bit – I’d rather look at a radar picture than have it described to me – but our newfound freedom does demand some significant responsibility. Since most of us don’t have formal weather training, we have to be disciplined about how we collect, organize and analyze preflight information.
Here are 10 lessons I’ve learned in the seven years since I last called Flight Service.
Have a flow. One way to avoid taking in either too little or too much information is to make a plan and have a structured process for preflight weather planning. I like to start with a wide perspective, then get progressively more local and more real time – much the way a standard weather briefing from Flight Service is structured. A good place to begin is with the surface analysis, then consider national forecast charts, then radar/satellite imagery, then local observations. This flow uses a building block approach, so each new piece of data (a METAR, say) fits into a larger theme (widespread marginal VFR conditions due to a surface low).
Get the big picture overview. One of the cardinal sins of weather planning is to blindly read METARs and TAFs without considering their context. Instead of being a mindless reader of weather information, think of it as a mystery that you have to solve: why is the weather the way it is? To answer this question, look at the big picture, particularly the location of lows and fronts. Then read the 300mb analysis and get a sense for the ridges and troughs, the highways that move weather around. Once you have this overview in mind, everything else is a matter of filling in details.
Make METARs visual. One of the ways technology has improved weather briefings is by transforming confusing text blocks into simple visual maps, and yet many pilots restrict themselves to raw METARs. Especially for VFR pilots, it’s far better to show those reports as a graphic. Is the low visibility at your airport an isolated event or widespread? With a single glance, you can answer the question. Almost all weather websites and apps have some version of this tool.
Understand the limitations of TAFs. The terminal forecast is an invaluable tool for pilots, whether IFR or VFR, but it’s critical to remember that a TAF is only for the immediate airport area (5 statute miles). If your home airport is in a river valley, a TAF for the big international airport 25 miles away on top of a hill may be just about worthless. Also remember that the age of the TAF says a lot about its accuracy. A four-hour old TAF is worth less than a brand new one. Read and understand the terminal forecast, but don’t give it too much weight – a good option is to read the forecast discussions found in many apps these days, which try to quantify the uncertainty found in most TAFs.
The trend is your friend. This is a basic concept, but it’s so powerful when used consistently. No matter what the actual METAR or TAF says, is it getting better or worse? If the last three METARs have all reported visibility dropping, it doesn’t matter what the TAF says – conditions are clearly worsening. Likewise, if the TAF originally called for clear skies at 8 am tomorrow, then was updated to show 3000 broken at 8 am tomorrow, you should be suspicious. You may wake up to find a 1200-foot overcast, as the developing trend gets ahead of the forecast.
Visibility usually matters more than ceilings. Would you rather have ten miles of visibility and 1500 overcast or three miles of visibility in rain under a 5000 foot broken ceiling? There’s no definitive answer, but in most cases I would take the ten miles. That marginal three or four miles can quickly become hard IFR (one or two miles) if precipitation increases, and even three miles is very demanding flying for VFR pilots.
Watch the weather before and after a flight. Plenty of pilots watch the weather well in advance of a flight (sometimes to a fault). While it’s sensible to start reading forecasts a few days before a flight, don’t limit yourself to those situations. There’s a lot to learn by following the weather every week, to get a sense for the patterns at work and to train your eye for common weather signatures. When you fly, watch the weather develop after you land. How did it compare to what you saw in flight? Each of these sessions is a chance to train your own personal weather algorithm.
Use new weather tools. The last 5-10 years have seen some great weather forecast products come on the scene. If your weather toolbox doesn’t include these new ones, you’re missing out on some valuable information. My favorites address three of our most consistent concerns in general aviation: thunderstorms, icing and turbulence. The CCFP and ECFP offer graphical depictions of convective weather, extending four to five days out, and really help plan a summer cross country. The CIP/FIP charts show forecast icing conditions at various altitudes and times in the future. It’s not flawless, but it’s becoming very good, and when combined with a big picture overview it can help you avoid the worst icing. Like the icing forecast, the GTG chart shows forecast turbulence at different altitudes and times. This was previously only available for high altitudes, but it now goes all the way to 1000 ft.
Find the tops if ice is around. For instrument pilots in piston aircraft, in-flight icing is one of the most serious threats from Mother Nature. The charts mentioned above are the best tool, but there’s more to consider. One of the best approaches is to aggressively search out reports of cloud tops, whether from PIREPs, area forecasts, forecast discussions or even satellite imagery. Combine all of these products with your knowledge of the big picture (hint: east of a strong low is a bad place to be). And remember: a lack of PIREPs does not mean it’s safe.
More isn’t always better. Being a weather geek can be fun, but some pilots suffer from analysis paralysis. If you have a good idea of the big picture, a feel for the trend, and all the supporting weather reports, it’s probably time to make the go/no-go decision. Reviewing Skew-t log(p) plots for every station along your route or devouring pages of coded MOS forecasts is interesting, but it probably won’t help you make a safe decision. You’ll either get confused by all the additional information or you’ll search for the one report that tells you it’s OK to launch – that confirmation bias coming back into play. Instead, make a plan, then follow it.
Technology has taken a lot of the mystery out of weather forecasting, filling in the gaps with more precise, more accurate and more comprehensive information. Given the abundance of weather products, it’s tempting to simply consume weather reports without thinking about them: “the TAF says it’ll be good, so we’re going!” That’s a dangerous mindset. A good pilot is still his own weather forecaster, suspiciously evaluating all the reports and forecasts he comes across and fitting them into a theory of what the atmosphere is doing at the moment of departure. A good pilot is also not afraid to use all the tools at his disposal.