The Winds of Flight - Getting Weather Information

Chapter 14 - Getting Weather Information

There are three places you can get weather information tailored to your flight: the Internet, the government, and the private meteorological sector. All have advantages and disadvantages. All the sources get their basic information from the same source - the worldwide data network which flows through the National Weather Service. The NWS is a big part of the communications networks of the International Civil Aviation Organization and the World Meteorological Organization. For the most part, the information you see is obtained from the government, either through the FAA, NWS, or one of the contract DUATS providers.

The Internet is growing and changing as you read this. When I tried putting the word "weather" in a search engine in 1998, I got around one million hits. Trying it again in 2000, I was told "7,235,855 pages found." I haven't tried all of them, or even a substantial portion, but, if you like surfing, there is a challenge. Periodically AOPA Pilot or the other magazines will have articles about finding weather information on the Internet. These help make you aware of the changes and new sites. While DUATS and the NWS's Aviation Weather Center should be a "must check," new ones will undoubtedly be available.

The National Weather Service has a policy that no "operational" forecasts will be distributed solely via the Internet. The reason is simply that the route of the information can go through a host of different computers. The circuit is not under anyone's control so the communications links may be broken at any time. If that happens, it's not anyone's fault. So the policy is that any NWS product on the internet be called "experimental." But, should you find an NWS product on the Internet, it is the same as the product which goes out over the other communications networks. Only the format might be changed to fit Web browsers. The disclaimer and the title "experimental" will probably be there indefinitely on Web products.

The area forecasts FAs), upper air forecasts UAs), and the terminal forecasts FTs) are scheduled products from the NWS offices. The FTs will probable be amended as the forecaster sees the need; however, most products are put out on a time schedule. If you get a briefing at noon, the briefer will use the latest FA and FT, but the latest one may be up to four hours old.

Operational meteorology exists as an amalgam of both private and public sector forecasters both doing what they do best. The private sector fills in the gaps by being available when needed. Certainly they use the government products which are updated to your needs and timing. If the private forecaster sees the FA going down the tubes, he or she will make the necessary changes for you. If you arrange for it, the private forecaster will update you in the air. However, don't surprise them too much or you won't get good service. You need to work with them. A good private meteorologist may save you more money than he or she costs. And, some of the private forecasters are surprisingly successful. Most of the airlines have their own meteorology departments; usually the dispatcher is a meteorologist. If you wish to locate one, try http://www.nws.noaa.gov/im/more.htm, through the American Meteorological Society at http://www.ametsoc.org/AMS/memb/ccm/ccmhome.html, or through the National Weather Association at http://www.nwas.org/corporate.html.

Small commercial aviation companies hire private meteorological companies to oversee their efforts. By way of example, one private forecaster spent a good bit of time and effort forecasting for a small commercial aviation outfit which was taking pictures for an advertising campaign in Australia. Not only did the forecasts involve the normal aviation-type worries, but it also involved forecasting the types of background clouds for the pictures for different areas so they could schedule the shoots. They worked hard for their bucks. The Federal government would like to think that it meets most of the needs of the aviation community. Realistically, the Feds can't meet them all. So, the decision on how to get the best weather information rests where it ought to, with the pilot. And, don't expect it for free. Aviation is inherently risky; it requires effort.

I can't say enough good about the FAA's Flight Service Briefers. Use them if you can get to them - or use the 1-800-WX-BRIEF if you can get through. While not meteorologists, the Flight Service Specialists have the latest available information and, generally, the experience to help you stay out of weather trouble. Listen carefully to them, but remember, the responsibility for the flight is yours.

Of course, all National Weather Service Weather Forecast Offices try to do good jobs of briefing. However, things have conspired to separate the pilot from the public briefers. NWS Offices are located at the larger airports such as Denver and Atlanta where few general aviation pilots will brave the traffic to get a briefing. At Chicago and Dallas, for example, the NWS can no longer afford sites on the field so they have moved. The new rural sites were picked for optimal radar placement. But, when one is available on the field, avail yourself of it. Then too, there is something comforting about an official forecast.

Don't forget the TV meteorologist. Many TV stations have them. Most, but not all, TV meteorologists have received the AMS Seal of Approval. To get the seal the forecaster should have a meteorology degree. The applicant then is evaluated and must pass a test made up by senior forecasters and administered by the American Meteorological Society. If you see the seal, the person is a qualified meteorologist. The National Weather Association has a similar seal program.

If you don't see the seal, use the information but be aware that the station doesn't put much emphasis on the weather show. One time when I was on a business trip, I can remember flipping channels one evening at weather segment time. The spouse gets after me about channel surfing. The three local news shows had three different weather maps on for the present weather situation. Yet, their forecasts were identical. None of the local weather casters had a seal but all subscribed to the NWS weather wire.

Many of us don't fly every day or every other day. A flight is an event. For those who do it every day, the process is one which is repeatable, and you can develop a system. For those of us who don't, I've constructed a "Weather Checklist." I showed it to a friend of mine, my favorite instructor, and longtime colleague, Art Flior. He showed me one in the document Weather, Flight Planning, and the Pilot being put out by the AOPA Air Safety Foundation. While there are a few differences, the ideas are the same. I hand both out to my classes, and if you like checklists, I recommend you study both carefully. I find that checklists are handy for me and I use them. However, I find that pulling it out every half-hour or so during a flight to repeat the "look at clouds" so I try to make a conscious check, asking myself - weather go/no-go - just after I switch tanks. If you want a one-page version which prints out reasonably well, click here.

Weather Checklist

Days Before Arrival at Airport

  1. Watch weather on TV.
  2. Look at clouds when outdoors or at window.
  3. Note speed of changes of weather in week days before flight.

Before Arrival at Airport

  1. Weather Briefing, FSS, DUATS, or Private Met.
  2. Winds aloft for flight plan.
  3. Crosswind component at both airports, alternate?
  4. Density altitude at airports in season.
  5. Temp-dew point spreads.
  6. Ceiling and visibility minimums - beginning, en-route and end.
  7. Check AWOS/ASOS if available.

Arriving at Airport

  1. Note clouds, visibility, virga.
  2. When parked, note cloud speed and direction.
  3. If there are two layers of clouds going in different directions, estimate warming, cooling.
  4. Surface winds, is crosswind component estimate correct?
  5. Is temperature different from that used in calculations?
  6. Thunderstorms visible?
  7. Surface; snow, standing water, snowmelt freezing on surface?
  8. If "severe clear" are there any dust-devils?
  9. Is weather conducive to what you want to do?

After Preflight and Runup

  1. Is OAT nearly same as temp used to calculate takeoff length?
  2. Check windsock for changes.
  3. Any thunderstorms visible?

Aloft - Every half hour or so make an active check

  1. Check Flight Watch occasionally (have them on the second radio.)
  2. Look at sky and winds on DME to see if they jibe with forecast, recalculate consumption if needed, adjust filed flight plan if needed.
  3. At night, check lights on ground for signs of fog.
  4. Look for signs of convection, lightning even in winter.
  5. Check icing/OAT.

Arrival

Can you make a comfortable, safe landing, taxi and tie-down?

This checklist requires some explanation.

As soon as you know you are likely to launch under your own responsibility, begin watching the weather both on TV and when you are outdoors. Look at the clouds while waiting for the train and try to visualize the processes going on. Try to translate what you see outdoors and while driving to what you see on TV. Many people look upon the happenings on TV as disjoint from life. The TV news for the most part portrays events which happen to other people. The weather segment is different. What you see is what you get, most of the time.

You can infer a number of things from the maps you see on TV. Figure 14-1 is a set of charts which I made up from TV charts on the left. I also used the temperature information to make up the pair of charts on the right. The spot of turbulence inferred in the southern Great Plains is inferred from the curvature in the inferred 500 mb chart. Where the lines on a chart make sharp curvatures, expect some turbulence. Since it is doubly inferred, it is suspect, but the inference may be the best you have.  You can do some checking when you are outdoors or even looking out the window. Are the winds blowing in the appropriate directions? Is the temperature reasonable for your location within the inferred weather? Are the clouds right?

You probably can't make a go/no-go decision a week ahead of time but you can make a "first draft" scenario. If it involves IFR and you're licensed, current, and sure of yourself, that's one thing. If you're strictly VFR or you want to carry passengers who are upset about taking off into a cloud bank with bumps, now's the time to consider alternate commercial reservations if you really have to go.

If the forecast looks for a nice VFR flight, you might be thinking of the types of clouds you should see enroute and where the neat things in the air might be found so you can show your passengers Nature's wonders. The nice thing about studying meteorology is that it gives you insight into the processes which are going on out there. For most people knowledge about the processes reduces the worry level and enhances the wonders of flight. For me, learning to fly was a new beginning to my studies of weather. Perhaps this start for you will also be a beginning.

Onward to Chapter 15 The Beginning or
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