Tuesday, January 1, 2008
Winter Flying: A Strategic Approach
Tips for staying safe in a cold season
In winter, I try to update myself on the weather and weather patterns in my area (and approaching my area) on a daily basis, even if I don’t plan to fly that day or if my flights will be local in nature. Having a feel for how fast frontal boundaries and low-pressure centers are moving can be invaluable in assessing winter flying risks. And winter flying is all about assessing and managing risk. I not only follow these weather features as they move across the country (including a review of the pertinent forecasts), but also try to guess the accuracy of the forecasts. A check of the current weather conditions at reporting stations along the pertinent weather feature will give a pretty good picture of how accurate the National Weather Service (NWS) forecast was for that time period and that area, and also how good my own “forecast” was.
Winter cross-country flights demand even more advanced preparation, and this is where the strategic nature of winter flying is most important. In winter, frontal systems and air masses are often larger and more difficult to predict than summer weather features. Frontal boundaries can stall, and low-pressure centers can intensify or move in a different direction than predicted. The keys to safe winter cross-country flying are educating yourself in aviation meteorology so you can make good assessments of potential weather conditions and looking ahead to try to determine what’s coming your way or what you may fly into.
In preparation for a winter cross-country flight, it pays to start looking at the “big picture” weather about three days in advance. Checking weather patterns more than three days in advance of a flight isn’t pointless, but weather patterns change so much and so rapidly that it’s difficult to forecast more than a few days in advance with much reliability.
To keep tabs on weather on a day-to-day basis, the primary tool I use is the Aviation Digital Data Service (http://adds.aviationweather.noaa.gov), provided by the NWS. This site contains useful aviation tools, including access to prognostic charts, text weather and forecasts, Doppler radar data and satellite imagery. It also provides links to public forecasts, which I like to peruse. The public forecast is often, if not always, prepared by a different meteorologist than the one who prepares the aviation forecasts. So, in effect, by looking at the local forecasts, you’re seeking a second opinion. Public forecast weather isn’t offered in aviation-specific parameters, so ceilings and visibility aren’t available there. What’s available is another forecaster’s assessment of when a given weather feature may reach your proposed destination or route of flight, and that can be valuable information. The estimate of when rain or snow may begin should align pretty closely with the aviation forecaster’s estimate of when ceilings and/or visibility will drop in the same area. If this isn’t the case, it can suggest that the weather feature causing the change may be a difficult one to forecast. Aviator beware.
There are many other Websites available providing access to a variety of weather products, such as the FAA-sponsored sites known as the Direct Access User Terminal Systems (DUATS) at www.duat.com and www.duats.com. AOPA also offers free online weather information for members at www.aopa.org. Another public Website that I frequently use is the Weather Underground site at www.wunderground.com (for you children of the ’60s—no, it’s not subversive, but it does have some great graphics). Television weather broadcasts such as those on the Weather Channel are also helpful in getting a handle on big-picture weather—particularly trends.
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