Results
#1. What will be the effect on the reading of an altimeter of an aircraft parked on the ground shortly before an active cold front passes?
As the cold air advances, it forces the warm air upwards causing the warm air to cool. The water vapour in the warm air mass, consequently, condenses, and clouds are created. The slope of the cold front boundary is steeper than that of the warm front, with a gradient of approximately one in fifty.
The unstable air just ahead of the cold front is, forced to rise vigorously. Causing pressure to reduce and altimeter reading increased
#2. In which approximate direction does the centre of a frontal depression move?
the whole of the polar front depression will move as the warm front and cold fronts move and will in fact narrow, as the cold front moves faster than the warm. The depression at the tip of the warm sector will move parallel to the isobars in the warm sector at a speed given by the distance between the first and second isobars.
#3. The cold front is indicated with a number at position:
triangles,are the standard symbols denoting a cold front.
hence 4
semi-circular Are denoting warm front
#4. In a polar front depression, an occlusion is called a warm occlusion when the cold air
If the air ahead of the warm front is colder than the air behind the cold front, then a warm type occlusion will be formed. This type of occlusion is more common in winter.
#5. The main factor which contributes to the formation of very low clouds ahead of a warm front is the
Because the warm air is being forced upwards into lowering atmospheric pressure, the air expands and cools. Water vapour in the air, therefore, condenses, creating cloud along the frontal boundary. The cloud takes on a horizontal, layered appearance since the slope of the warm front is about one in one hundred and fifty, much shallower than the slope indicated in the diagram This layer-type cloud is called stratiform cloud.
#6. A squall line usually is most likely to be encountered
Squall lines are observed frequently in the warm sector of a midlatitude cyclone, usually about 100–300 km in advance of the cold front. Divergence ahead of an upper-level trough induces low-level convergence.
#7. When do cold occlusions occur most frequently in Europe?
the air behind the cold front is colder than the air ahead of the warm front, then a cold type occlusion will be formed. This type of occlusion is more common in summer.
#8. The polar front is the boundary between:
The polar front is a boundary between warm Tropical Maritime and cooler Polar Maritime air
#9. Which of the following is typical for the passage of a cold front in the summer ?
instability in the warm air which is in direct contact with the wedge.
unstable air just ahead of the cold front is, forced to rise vigorously. This vigorous vertical ascent creates vertically developed cumuliform cloud
#10. The warm sector is indicated by letter:
triangles,are the standard symbols denoting a cold front.
semi-circular Are denoting warm front
The area lying between the two fronts is known, since it is covered by tropical air, as the warm sector.
#11. In which air mass are extremely low temperatures encountered?
If the airmass is lying over a warm tropical ocean, the airmass is classified as Tropical Maritime (TM).
If the airmass lies over a cold continent in winter, the airmass is classified as Polar Continental (PC).
#12. What characterizes a stationary front?
stationary front is a weather front or transition zone between two air masses (cold and warm), when neither air mass is advancing into the other at a speed exceeding 5 knots at the ground surface.
#13. What type of front / occlusion usually moves the fastest?
The reason why cold fronts have more severe weather is that they are displacing the warmer air mass in a far faster manner. This displacement moves air vertically upwards and the steepness results in taller, cumulonimbus clouds.
Warm fronts conversely, move the air in a gentle slope. This causes a slower displacement of air which produces shorter clouds, spread out in a larger horizontal area.
#14. What will be the effect on the reading of an altimeter of an aircraft parked on the ground during the period following the passage of an active cold front?
#15. Where does polar continental air originate?
Poles or Siberian land mass
#16. After passing at right angles through a very active cold front in the direction of the cold air, what will you encounter, in the northern hemisphere immediately after a marked change in temperature?
as you have passed the cold front in the direction of cold air you are behind the cold front
Behind the cold front
Surface W/V – Steady or slight veer to NW.
Temperature – Steady low. Dew Point – Steady low.
Pressure – Rises slowly.
Cloud – 6/8, base lifting, isolated Cu, Cb.
Precipitation – Showers, heavy at times, hail and Ts possible.
Visibility – Very good, except in showers.
#17. In which of the following regions does polar maritime air originate?
#18. How do air masses move at a warm front?
warm air is replacing cold air, then the front is called warm.
A warm front has an approximate slope of 1:150 and a side view is as shown below. Generally as the warm front approaches the cloud will lower and thicken. Precipitation will start and gradually increase in intensity until the front passes. Visibility will also decrease and eventually fog may appear when the surface front arrives.
#19. What types of cloud will you meet flying towards a warm front?
#20. (For this question use annex A) Refer to the diagram. Assuming the usual direction of movement, to which position will the polar frontal wave have moved?
These depressions are called the Polar Front Depressions or Warm Sector Depressions and they move west to east along the polar front with the general westerly upper winds, reaching NW Europe from the Atlantic Ocean
#21. In which main direction does a polar front depression move?
These depressions are called the Polar Front Depressions or Warm Sector Depressions and they move west to east along the polar front with the general westerly upper winds, reaching NW Europe from the Atlantic Ocean
#22. The front labeled “1” is a:
Warm front occlusion will be an extension of the warm front.
from point 1 to 3 it is kind of a straight line from warm occlusion to warm front
More elaborate figure red to purple is one line
cold type occlusion
cold front and cold occlusion are one straight line
#23. How are the air masses distributed in a cold occlusion ?
#24. (For this question use annex F) Which typical weather situation is shown on the weather chart? (Spacing of the isobars: 5 hPa)
as the isobars are not closely packed and there are more high than low, it will be calm and uniform pressure pattern
#25. (For this question use annex B) Refer to the diagram. Assuming the usual direction of movement, where will this polar frontal wave have moved?
These depressions are called the Polar Front Depressions or Warm Sector Depressions and they move west to east along the polar front
#26. Where is the coldest air to be found, in an occlusion with cold front characteristics?
#27. What cloud cover is typical for a wide warm sector of a polar front depression over Central Europe in the summer ?
The area lying between the two fronts is known, since it is covered by tropical air, as the warm sector.
In the warm sector.
Surface W/V – Steady, usually from the SW.
Temperature – Steady.
Dew Point – Steady.
Pressure – Steadily decreasing.
Cloud – Uniform 6/8 to 8/8, some large breaks may occur, base low, St, Sc.
In summer over land – fair weather cumulus
Precipitation – Light rain, drizzle Visibility – Poor.
#29. At the approach of a warm front (northern hemisphere) the wind direction changes from the surface up to the tropopause. The effect of this change is that the wind
Upper wind will veer in northern hemisphere
#30. (For this question use annex C) Which cross-section of air mass and cloud presentation is applicable to the straight line A-B?
the question shows plan view and the answer is profile view
as you can see the warm font and warm occlusion in plan view are a straight line this will be represented by profile view with coldest air ahead
answer is 3
#31. What is the surface visibility most likely to be, in a warm sector of tropical maritime air, during the summer?
#32. On an aerodrome, when a warm front is approaching
#33. During a cross-country flight at FL 50, you observe the following sequence of clouds: Nimbostratus, Altostratus, Cirrostratus, Cirrus. Which of the following are you most likely to encounter?
Warm front approach with cold air ahead
#34. How do you recognize a cold air pool?
COLD AIR POOLS
These are outbreaks of cold air from near the poles. These outbreaks are usually characterized by a cold front at their leading edge. In fact they are common just behind the polar front depressions
Although surface temperature anomalies such as cold pools are not evident on surface pressure charts, they can be found most notably by looking at pressure charts in the middle to upper atmosphere. You may remember that cold air causes pressure to fall more rapidly with height, reducing the pressure in the upper atmosphere. Therefore by analyzing a pressure chart in the middle to upper atmosphere you can identify cold air pools by the low pressure they create
#35. What is encountered during the summer, over land, in the centre of a cold air pool?
These are outbreaks of cold air from near the poles. These outbreaks are usually characterized by a cold front at their leading edge.
Although surface temperature anomalies such as cold pools are not evident on surface pressure charts, they can be found most notably by looking at pressure charts in the middle to upper atmosphere. You may remember that cold air causes pressure to fall more rapidly with height, reducing the pressure in the upper atmosphere. Therefore by analyzing a pressure chart in the middle to upper atmosphere you can identify cold air pools by the low pressure they create,
Low pressure is accompanied by showers and thunderstorms
#36. Which of the following describes a warm occlusion?
#37. Thunderstorms can occur on a warm front if the
the air is moist and unstable, then the uplift caused as it passes over the depression can ensure that Cu and Cb with showers and possibly thunderstorms and hail may develop.
#38. What is the relative movement of the two air masses along a cold front?
#39. What type of precipitation would you expect at an active unstable cold front?
#40. Frontal depressions can be assumed to move in the direction of the 2000 feet wind
The area lying between the two fronts is known, since it is covered by tropical air, as the warm sector.
The warm sector and the whole of the polar front depression will move as the warm front and cold fronts move and will in fact narrow, as the cold front moves faster than the warm. The depression at the tip of the warm sector will move parallel to the isobars in the warm sector at a speed given by the distance between the first and second isobars
.
#41. Read this description: “After such a fine day, the ring around the moon was a bad sign yesterday evening for the weather today. And, sure enough, it is pouring down outside. The clouds are making an oppressively low ceiling of uniform grey; but at least it has become a little bit warmer.” Which of these weather phenomena is being described?
Approaching ci clouds
Cirrostratus is made up of ice crystals, and lies between 18,000 and 45,000 ft. Cirrostratus is a further warning of an approaching frontal system, and, like altostratus, may cause the Sun and Moon to appear with a halo.
Heavy rain
and dark ns clouds
#42. What are the typical differences between the temperature and humidity between an air mass with its origin in the Azores and an air mass with its origin over northern Russia?
Tropical Maritime.
Source: The Azores. Warm, stable, absolute humidity high, RH moderate.
Polar Continental.
Source: Siberia (winter only). Stable, very cold and dry.
#43. (For this question use annex D) Examining the pictures, on which one of the tracks (dashed lines) is this cross-section to be expected?
Cold front and occlusion are moving together
hence it is a cold occlusion
profile view would like like this
which would be from b to d
#44. (For this question use annex E) Under the weather conditions depicted, which of the following statements is likely to apply?
The are where low pressure exists is SW Europe, the finger-like protrusion is a trough which guarantees weather like thunderstorm
#45. What cloud formation is most likely to occur at low levels when a warm air mass overrides a cold air mass?
warmer air, being less dense, will ride up and over the colder air is called warm front
This is the weather experienced
#46. Which of the following conditions are you most likely to encounter when approaching an active warm front at medium to low level ?
fog at medium to low level
#47. The approximate inclined plane of a warm front is:
#49. Which of the following zones is most likely to encounter little or no precipitation?
The Föhn Wind is a warm dry wind which blows on the downwind side of a mountain range.
On the south of alps If moist air is forced to rise up a mountain side, it will quickly become saturated and will cool adiabatically as it rises. After reaching the condensation level, cloud will form and the air will cool at the SALR. Raining on south side ,north side will not have rain
#50. What will be the effect on the reading of an altimeter of an aircraft parked on the ground as an active cold front is passing?
#51. Which of the following statements concerning the core of a polar front jet stream is correct?
Polar front jet streams move north in summer and south in winters,
the area of max speed is axis
immediately surrounding axis is called core
At the height of polar front jet stream core (39000 feet )there is no horizontal temp gradient