FAA Aircraft Dispatcher Practical Exam | Questions with 100% Correct Answers | Verified | Latest Update 2024 | 23 Pages

How often are METARs issues? - Every hour, or whenever the weather changes and necessitates a change. In that situation, a SPECI (special METAR) is issued. What is a SPECI? - A special METAR which is created in between the hourly METARs due to a change in weather necessitating the change. -Change of winds necessitating a new runway. -WX changing from IFR to VFR or VFR to IFR. Do METARs describe actual or forecast conditions? - METARs depict actual field conditions. Define Radiation fog - Shallow fog, ground fog. occurs on clear nights, little or no wind, and small temp/DP spread (high relative humidity). Occurs at night or daybreak. Radiation cools the ground. The ground cools the air. When the air is cooled to the dew-point, fog forms. Define Advection fog - This fog forms when moist air moves over colder ground or water. Common along the coast. What is lake effect? Describe one major consequence of lake effect in winter. - Air moving across a sizeable lake absorbs water vapor. Showers may appear on the leeward side if the air is colder than the water. If the air is warmer than the water, fog often develops on the leeward side. In the winter, lake effect snow is a concern because as a cold front passes over the warmer lake water, snow, instead of showers will occur.