The Weather Never Sleeps

Cracking Those FA Codes

As a pilot gathers the information needed for a preflight weather briefing, the area forecast almost asks to be ignored. After all, you would really have to enjoy untangling coded weather reports to willingly tackle a forecast that starts off with something like: "SYNOPSIS... LOW PRES TROF 10Z NERN PA-SERN NY-SWRN CT FCST MOV EWD INTO CSTL WTRS AND WKN THRU 04Z. LARGE AREA HI PRES FCST BLD EWD OVR LE-OH THRU 04Z...SMITH ...NERN ME...OVC050. TOPS FL200. 15Z OVC030. AFT 18Z SCT-SHSN..."

If an area report was as short as the excerpt above, you might be willing to take a shot at it. But on an ordinary day, when meteorologists don't have a lot to say about the weather, the printout of an area forecast can run more than two pages long. As if page after page of code in capital letters - which any type designer will tell you are hard to read - isn't enough, area forecasts identify areas of dangerous weather by asking you to play connect-the-dots using the three-letter identifiers of VOR radio navigation stations and airports.

A pilot who has flown for a few years along the Appalachian Mountains might be able to look at something like, "FROM JHW TO PSB TO PSK TO HMV TO HNN TO JHW MTNS OCNL OBSC IN CLDS AND PCPN. CONDS ENDG 17-19Z" and draw a line on charts outlining the area where the "mountains (are expected to be) occasionally obscured in clouds and precipitation, conditions ending 1700 to 1900 Zulu time," as the forecast says. But most of us would have to search a list of three-letter identifiers to figure out that the mountains are going to be obscured inside the area enclosed by lines drawn from Jamestown, New York, to Phillipsburg, Pennsylvania, to Dublin, Virginia, to Houston Mountain, Tennessee, to Henderson, West Virginia, and back to Jamestown.

Yet the information in area forecasts is vital for any pilot who is planning to fly away from the airport where he or she launches. It's the only weather forecast that tells you what the ceilings and visibilities are anticipated to be over large areas. Area forecasts are also the only source that will give you an idea of what ceiling and visibility to expect if you are flying to one of the many airports for which no specific terminal aerodrome forecast is available.

Fortunately, if you call or visit an FAA flight service station for your weather briefing, the specialist you talk with will not only take care of translating the area forecast and other reports, but he or she will also pull out the information you need for your flight. This is only one of the reasons why a flight service station is the best way to obtain a preflight briefing, especially for a pilot who isn't thoroughly familiar with weather and the weather reporting and forecasting system.

If you want to use the Direct User Access Terminal System (DUATS) to call up a weather briefing on your computer, you can find ways to leap some of the hurdles offered by area forecasts, including finding the locations used to outline areas of dangerous weather. First, however, you need to learn some of the basics about area forecasts, including what they do and do not contain.

The National Weather Service's Aviation Weather Center in Kansas City, Missouri, issues area forecasts three times a day for six areas that cover the contiguous 48 states. Each forecast is named for a large city in the area covered. Figure 1 shows these areas with the city name used for each. Forecasts are issued in the predawn hours (local time), in the morning, and in the early afternoon. They cover a 12-hour period with a six-hour, generalized outlook. National Weather Service offices in Alaska and Hawaii issue area forecasts for their states four times a day. All of the times used in area forecasts are Coordinated Universal Time, which used to be called Greenwich Mean Time and is commonly called Zulu time by pilots and meteorologists.