Strong winds can cause some of the most dangerous  conditions you’ll have to contend with in the moun› tains. To ininimize the chance. of encountering danger› ous turbulence, mountain flying should not be  attempted if the winds aloft forecast at mountain top levels are  greater than 25 knots. Above this level, potentially dangerous tur› bulence, as well as very strong up and down drafts are likely.  Experienced mountain pilots recommend that IFR and night flight  in  the mountains not be attempted. Instrument approaches and  departure procedures require a highly skilled pilot and a very high  performance airplane. Night obviously obscures most visual navi› gation cues. making terrain clearance difficult or impossible.  From your basic flight training, you probably remember that densi› ty altitude is the pressure altitude corrected for temperature. Since  increasing temperature makes the air less dense, an airplane will  perform as if it is at a higher altitude than on a colder day, given  that the airplane  is  at the same height above sea level.  You should also remember that the standard lapse rate (the rate at  which temperature normally decreases with increasing altitude in  unsaturated air) compounds the problem somewhat. At sea level,  the standard temperature is 59 degrees Fahrenheit, however, at  10,000 feet MSL, the standard temperature is only 23 degrees. This  means that at Leadville, Colorado (elevation 9,927 feet) when the  temperature is only 24 degrees, the density altitude is already  above the field elevation. We will discuss density altitude  in  more  detail later.  The winds aloft reports are very important to your mountain flight  planning process. You should pay close attention to the forecasts  at and above the mountain ridges of the terre in you will be flying  into. In the west, that usually means the 9,000 and 12.000 foot fore› casts. In the east, you will look at lower winds. Winds above 25  knots at these levels should be a warning sign that should cause  you to think about delaying your trip.  Winds Aloft Reports  Weather Factors  Density Altitude  IFR and Night Mountain Flights  Winds  A  5 