The air near the surface will usually become warmer throughout the day. This is one of the main reasons why it is unstable. Then at night, the air that is close to the surface will begin to cool. This is going to form a temperature inversion or a stable atmosphere.2. Inversions aloft are sometimes called “capping inversions” or “lids”. Why?
This is because it is like putting a lid on the atmosphere.
3. You are flying at 4,000 feet AGL over a city during the day. There are no clouds present. As you descend to land at a nearby airport, you notice that, although visibility was very good at 4,000 feet, there is a marked decrease just below 2,500 feet AGL. As you make your final approach, you observe a distinct increase in visibility near the ground. Give a reasonable explanation of the meteorological situation on the basis of what you know about stability.
The best explanation is that there is a storm coming so it caused the clouds to lower.
4. Explain how air can rise when it is stable.
The air can be forced upwards because of the front/dryline or orography.5. Under the conditions described in question 3, a parcel of air is lifted from the surface to 1,500 feet AGL. What is the parcel temperature at that level? Is it stable or unstable? Explain why, from the perspective of parcel temperature and lapse rate.
The parcel temperature at this level is about 31C. Therefore, it is not stable. In order for the parcel temperature to be stable it is going to need to be higher.6. The surface air temperature at your airport is 86 degrees Fahrenheit. There is no sounding, but an aircraft reports 80 degrees Fahrenheit at 1,300 feet AGL on climb out. Do you expect turbulence on takeoff? Explain.
Yes there is probably going to be a little bit of turbulence on takeoff. This is because the high temperature means that they might be some storms in the atmosphere.7. What happens to air parcels displaced downward in a stable atmosphere? Why?
The air parcels are going to warm up once the pressure increases.8. It is often observed that relative humidity reaches a maximum near sunrise and a minimum in the afternoon. Why?
It is because that is when the air temperature is at its miniumum. 9. If a saturated parcel is descending, say in the middle of a rain shower, is the rate of heating of the parcel less that or greater than 3 degrees Celsius per 1,000 feet? Why?
It is going to be greater than 3 degrees Celsius per 1,000 feet. This is because as the saturated parcel descends, the rain is going to cause a higher temperature.10. Is there any truth in the adage, “too cold to snow?”
No. There are three main conditions that need to happen in order for it to snow. The first condition is based on the temperature so that the snow can reach the surface. The second condition is the saturated air. The third condition is the lift of the surface.11. You are in a pressurized cockpit that undergoes rapid decompression. Fog forms suddenly in the cockpit, then dissipates. Explain.
The lower altitude means that there is more water vapors and the warmer air parcels. The decompression causes the temperature and dew point to change so the vapors will condense.12. You are standing next to your airplane preparing for a night flight. It is overcast and the visibility is very good. Rain starts abruptly. You notice the droplets are quite large. The rain stops after a minute or so. What can you say about flying conditions at cloud level?
It would not be a good idea to fly in these conditions because of the embedded CB clouds. If there is a sudden change with bigger droplets of rain, it could cause even more problems with the flight.13. You place a gallon can, partially filled with water, on a burner until it comes to a boil. You remove the can from the burner and cap it. After a while, the can begins to collapse. Explain.
The pressure of the water will be relieved even when the boiling continues so it will cause the can to collapse.14. You walk out to your aircraft for preflight just before sunrise. It is parked in the open. It has been clear all night. There is no moisture on the ground, but you find a thin layer of ice on your wing. Explain.
It is probably from the dew of the night. When it gets hot at night, there might be moisture in the air causing ice of the wing.15. Aerodynamic contrails can often be seen streaming from aircraft wingtips on takeoff while exhaust contrails typically occur at high altitudes. Give a realistic example of a meteorological situation where exhaust contrails are produced from an aircraft on the ground. In what geographical location would such a situation most likely occur?
This type of situation is most likely to occur when the area is very dry because of the high humidity in the area.16. You are responsible for advising an oceanic research group on the operation of an aircraft flight to do a low-level photo survey of the Atlantic between Panama and Gibraltar. You will be flying at about 1,000 feet MSL at an airspeed of 170 knots. Flight will be made one day a week for a year. There will be a full crew and scientific equipment going one way. The direction is arbitrary. The crew and equipment will return by commercial airline. It is up to you to minimize the cost of the missions (fuel, crew duty time, etc.). On the basis of average conditions in January and July, what would your meteorological advice be?
I believe that it would be okay to fly during this time. This is because the weather is usually pretty good during these times in this area.17. A minimum time track (MTT) is not necessarily the shortest path between two locations but it is the fastest. Your company aircraft flies a daily, round trip flight from London to New York for a period of one year. The airspeed is 300 knots at an altitude of 18,000 feet MSL. On the basis of January and July conditions, give a rough estimate (draw a map) of how the average annual MTTs for the out and return flights would look? Discuss your reasoning. Would your answers change for flights at 300 mb? For an aircraft flying at Mach 3? If so, how?
The flights should be fine for these areas and it should not change.18. You want to fly a balloon across the Atlantic. For technical reasons you must fly below 5,000 feet MSL. You want dependable (steady) winds. Where and when should you attempt your crossing? Discuss.
The best time to fly will be in January because the Bermuda High will have the greatest pressure difference between it and the Icelandic Low. Therefore, if you get the balloon between them, the wind will be more stable and constant. The balloon could have global circulation winds and the prevailing westerly to help push you across the Atlantic Ocean.19. You are trying to land at an airport before the arrival of the weather associated with a cold front passage. The front is approaching the airport at a speed of 10 knots. You have been in the cold air mass for almost your entire flight and you manage to fly through the front into warm air at 3,000 feet AGL, about 5 n.m. from the airport. Your airspeed is 120 knots. Will you reach the airport before the front does? Discuss.
A typical cold front will have a slope of 1:50 to 1:100. Therefore, the stratocumulus will be 1 n.m. or 50-100 n.m. Breaking through the cold front at 3000 ft will theoretically mean that it will still be able to extend out at least another 25 nautical miles at the ground level. This means that the front has almost certainly passed the airport already which is only 5 n.m. away from my current position at ground level. 20. Several years ago, when a typhoon was approaching an airfield on a pacific island, it was determined that the eye of the storm would actually cross the base where several large aircraft were parked in the open. There was no hanger space and although it was too late to fly the aircraft to safety, minimum aircrews were placed in the aircraft. Why? Discuss.21. Why does the front aloft precede the surface front by a large distance in a warm front occlusion and follow the surface front at a shorter distance in a cold front occlusion?
When the front leans upward from the surface, then the slope of the warmer air will rise and cool so that it form the clouds and the precipitation. 22. Make a table that contrasts the following characteristics of extratropical cyclones and hurricanes.1. Geographical region of development – low pressure zones, 2. Initial direction of movement – north or southward3. Energy source – converts the potential energy that is created by the pole to the equator temperature gradients to eddy the energy.4. Altitude of greatest intensity – The North Atlantic5. Stages of development – the initial stage, the incipient stage, the mature stage, the occlusion stage6. Scale - 1000 kilometres (about 620 miles) or more7. Temperature structure – colder air8. Weather – blizzards, snow23. As you complete the preflight inspection of your aircraft, you notice lightning and rain south of the airport. You can’t really see any movement of the storm. The airport winds are from the south. The airport is isolated and uncontrolled. You have no radar or other supplementary meteorological information. Discuss your options.
The best option is to ground the flight until you can get better information from a radar.24. Convection also occurs at high levels producing altocumulus and cirrocumulus clouds. Surface heating obviously doesn’t play a role. What is the source of the instability?
The source of instability is temperature of the air mass.25. On a particular summer day, you notice that thermals are exceptionally strong. Fair weather cumulus clouds form, but there are no thunderstorms. Why?
There is a cold front which makes the air very unstable.26. In the morning, the K index is 32, what are your conclusions about thunderstorm occurrence in the afternoon?
Since the K index is less than 40, then a thunderstorm is probably not going to occur this afternoon.27. Occasionally, aircraft will experience strong turbulence in a part of a convective cloud that does not show up on the radar. Give some reasonable explanations.
The turbulence could be coming from clear air. This is because it cannot be picked up by a radar.28. The wind at 200 feet AGL is 330 degrees at 15 knots. The surface wind 240 degrees at 15 knots.1. What is the wind speed difference over the 200-foot layer?
The wind speed difference over the 200 foot layer is that it will decrease,2. What is the total wind shear (magnitude only) between the surface and 200 feet AGL?
There will be lower winds.3. What is the severity of the LLWS?
The severity of the LLWS can go light to severe depending on the magnitude 29. You are taxiing out in preparation for takeoff from an uncontrolled airstrip. An isolated rain shower can be seen over the opposite end of the runway. There is no thunder or lightning.1. Should you take off?
No I do not think it would be a good idea.2. Why?
It is because it could be really dangerous to fly in this rain.
3. If you elect not to take off, about how long will you have to wait until you can go? Explain.
It is a good idea to wait for a couple of hours to make sure that the rain is gone.30. At just about sunrise, a pilot is descending to land on an island, between the ocean and a range of volcanic peaks. The prevailing winds are easterlies. On final approach from the west, strong LLWS is encountered at 100 feet. Explain why this happened/
This happened because the magnitude of the area was low.
31. The critical period for a low-level wind shear hazard is longer for a warm front than for a cold front. Why? There are two reasons.
The first reason is the duration of the wind shear. The second reason is the change in the wind.List three causes of non-convective LLWS.
There are three main causes of non-convective LLWS: frontal passage, low-level temperature inversion, and orographic effect.32. You are approaching a north-south mountain range from the east. Mountain top is 10,000 feet MSL. Your altitude is 12,000 feet MSL. 500 mb winds are 340 degrees at 25 knots. 700 mb winds are 270 degrees at 35 knots. Discuss. Consider the same situation but this time your approach is from the west.
25-40 kt winds at the top level of the mountain can produce moderate turbulence. The most severe turbulence is will expected when the winds exceed 40 kt and will run perpendicular to the ridge top. While the winds are perpendicular to the ridge line, there are some areas where the turbulence is likely to occur when it is below the level of the top of the ridge or within 5000 ft of he tropopause. The Mountain Wave Turbulence could be expected on the downwind side of the mountain range but they will not be severe.
33. You are diverting around a thunderstorm on the downwind side. The sky under the anvil is clear. If you fly under the anvil, it will save time and you might not have to stop for additional fuel. Discuss your options and risks of each option.
The best option is to fly under the anvil so I do not have to worry about the turbulence. The only risk is that I would have to fly lower than I should.
34. If you are flying over the North Pacific at 30,000 feet MSL with a strong tailwind and you encounter CAT, what would you do to get out of it? Explain.
I will get the tailwind of the storm because of the direction that I am going in.35. The tower has just cleared you to land behind a 757. The reported wind is a seven knot crosswind.1. Do you see any potential hazards in this situation?
No I do not see any potential hazards in the situation.2. If so, what are your options and the risks associated with each option?
No different options or risks involved.36. What is the danger of runback icing?
The danger of runback icing is that the water droplets that impinge around the leading edge do not freeze upon striking the surface because the surface temperature is above freezing. The liquid water then runs back of the freezing area to where the surface is below freezing and the ice will form there.37. What are your chances of carburetor icing when the temperature is 30 degrees Celsius and the temperature-dewpoint spread is 12 degrees Celsius?
The chances of the carburetor icing is very likely because of the temperature is low enough.38. Several layers of clouds exist between 2,000 feet MSL and FL200. The freezing level is at 5,000 feet MSL. Use the standard atmosphere to estimate the top of the layer where icing would most likely accumulate during a climb out to 15,000 feet MSL.
It is going to occur in the approach and the landing.39. Why do supercooled large droplets (SLD) often cause worse icing problems that smaller supercooled cloud droplets?
It will strike the aircraft when the temperature is colder than 0 degrees. 40. Why are wintertime warm fronts often producers of heavy icing events?
This is because the clouds will drop water that is supercooled because it is 32 degrees Fahrenheit.41. Why is icing usually not a problem in cirrus clouds?
They are made up of ice crystals unlike the other clouds that are made of condensed droplets of liquid water.42. Explain why ice pellets indicate that freezing rain or freezing drizzle exists at a higher altitude.
If the temperature of the cold air is below freezing, then the rain that is falling from the warm air above may freeze before it reaches the surface.43. Discuss the meteorological concerns of a VFR descent.
The concerns are rain, moderate turbulence and the clouds that can form in a VFR descent.44. You are at an isolated airport in a generally flat area far from the ocean. It is a fall evening, the skies are clear, and winds are light. There is no forecast for your local airport, but the forecast for a station 100 miles away indicates the chance of dense fog at the time you intend to take off (0600 the next morning). You are carrying a perishable cargo that you must begin loading four hours before takeoff. It is very expensive to load and unload, so you want to make a decision before you begin to move the cargo. Aside from the previous forecast, you only have local observations. At 0200, it is clear. What should you do?
It should be okay to take off at this point.45. At sunrise on a clear, calm day, a whitish haze has reduced the visibility at the local airport. Ground fog exists along nearby creeks. Do you expect visibility conditions to improve in the next few hours? Explain.
Yes most of the time in the morning visibility can be difficult but it usually clears up later on in the morning.46. It is midnight in winter. Large-scale weather conditions how a stagnant high pressure system over your area. Radiation fog occurred under clear skies last night and burned off at 0900 this morning. Fog has formed again this evening. The midnight sky condition is BR SCT000 OVC100. Will it be possible to fly VFR tomorrow morning at 0930? Discuss.
Most of the time, it is going to be later on in the morning. This is because the conditions will still be unclear.47. In whiteout conditions, it has been said that objects appear to “float in the air.” What causes this?
This is caused by the fog in the area is going to cause the water to evaporate.48. What causes lightning to occur with volcanic eruptions?
The lightning is called by a flow of electricity between the two masses that have the opposite positive and negative charge. 49. Mt. St. Helens, which erupted in southern Washington State, caused much devastation on the ground. However, the ash cloud did not have the same long-term effects as ash clouds from either Mt. Pinatubo in the Philippines or El Chichon in Mexico. Why? (Hint: do some research on the description of the Mt. St. Helens eruption.)
This is because the cloud buildup that was around when the volcano erupted.50. Prepare a list of specific text and graphic weather products that provide observed or forecast information about the following phenomena.1. Turbulence – high wind, thunderstorm, lightning2. Thunderstorms – rain, wind, thunder, lightning3. IFR conditions – visibility is limited4. Icing – snow, freezing rain (Federal, 2011).
References:
Federal Aviation Administration Federal Aviation Administration. (2011). Instrumental Flying
Handbook. Skyhorse Publishing: New York, New York.
