Aero-Tips!
A good pilot is always learning -- how many times have you heard
this old standard throughout your flying career? There is no truer
statement in all of flying (well, with the possible exception of
"there are no old, bold pilots.")
Aero-News has called upon the expertise of Thomas P. Turner,
master CFI and all-around-good-guy, to bring our readers -- and us
-- daily tips to improve our skills as aviators. Some of them, you
may have heard before... but for each of us, there will also be
something we might never have considered before, or something that
didn't "stick" the way it should have the first time we memorized
it for the practical test.
Look for our daily Aero-Tips segments, coming each day to you
through the Aero-News Network.
Aero-Tips 08.01.06
One tool useful in making a broad go/no-go decision is the
satellite view. Radar shows precipitation, but satellite pictures
show more extensive cloud cover even away from rain or snow.
There are actually three types of satellite view -- the visible
cloud cover chart, the infrared satellite view, and the water vapor
imagery.
The visible cloud cover chart is
just that -- a photograph from space that shows areas of cloud
cover. The brighter the cloud image the higher the cloud tops,
which may correlate to thunderstorms but may also depict harmless
high cirrus clouds.
Note the eastern part of the U.S. appears dark-it's after sunset
in the east, so there's no sunlight to reflect off the cloud tops
and the picture is about meaningless. All is not lost-there's also
an infrared view for nighttime imagery. The infrared is available
both in black and white and color.
Look at New York State in the visible and infrared images --
what looks benign on the nighttime satellite chart in instead
potentially hazardous on the infrared. Look also in the area near
St. Louis, Missouri, and you'll see that, in daylight, the visible
and infrared images correlate closely.
The water vapor image takes this
a step further, graphically showing where the air is its wettest,
giving the highest potential for storms or extensive
cloudiness.
Remember that moist air cooling at night can create low clouds
and poor visibility in fog. The area west of Missouri's high clouds
shows a lot of moisture, for instance -- pointing to possible
evening storms or reduced visibility as the evening air cools and
promotes condensation.
Note that on all satellite views you're seeing the tops of the
highest layer of clouds or vapor... not what lies underneath. Taken
together, they show areas of extensive cloudiness, the possibility
of storms and, perhaps most notably, the availability of abundant
moisture that may develop into clouds, fog or storms.
Aero-tip of the day: Supplement your preflight
self-brief with a look at the visible and infrared satellite
images, and the water vapor imagery.