Weather Flashcards
Why does it rain so much in the Lake District?
The prevailing westerly winds cross the Atlantic Ocean picking up large amounts of moisture. The air hits the Lake District hills and is forced to rise where it cools and the moisture condenses to form rain. This is called relief or orographic rainfall.
What is meant by the term
adiabatic lapse rate?
The two main types are the dry adiabatic lapse rate, which applies to unsaturated air.
Moist adiabatic lapse rate, which applies to saturated air.
The adiabatic lapse rate refers to the rate at which the temperature of a parcel of air changes as it rises or descends in the atmosphere without exchanging heat with its surroundings.
The two main types are the dry adiabatic lapse rate, which applies to unsaturated air, and the moist adiabatic lapse rate, which applies to saturated air.
The dry adiabatic lapse rate is approximately 9.8°C per kilometer (5.4°F per thousand feet), while the moist adiabatic lapse rate varies depending on the temperature and pressure, but is generally lower than the dry adiabatic lapse rate due to the release of latent heat as water vapor condenses.
What is the dry and moist adiabatic lapse rate change in °C per Km or 100 meter ascent?
What is the dry adiabatic lapse rate change in °C per Km or 100 meter ascent?
Dry is approximately 10 for 1 km or 1 °C per 100 meters.
Moist lapse rate varies depending on the temperature and pressure, but is generally lower so would be approx 5 for 1 km or . 5 °C per 100 meters.
In meteorology, what is inversion?
In meteorology, an inversion refers to a deviation from the normal decrease in temperature with increasing altitude in the Earth’s atmosphere.
Typically, the air near the surface is warmer than the air above it.
However, during an inversion, a layer of warmer air traps cooler air below it, preventing vertical mixing and leading to stable atmospheric conditions.
This often results in fog, smog, or poor air quality, as pollutants can become trapped beneath the inversion layer.
Inversions can also affect weather patterns and lead to temperature differences between areas above and below the inversion layer.
In meteorology, what is meant by the saturation point?
In meteorology, the saturation point refers to the point at which the air holds the maximum amount of water vapor possible at a given temperature and pressure. If the air is further cooled, it can no longer hold the moisture, leading to condensation or precipitation.
What is the windchill factor?
Wind chill refers to the perceived decrease in air temperature felt by the body on exposed skin due to the combination of cold air and wind. It’s essentially how cold it feels, rather than the actual temperature.
The wind chill index is calculated using a formula that takes into account the air temperature and the wind speed. The formula varies slightly depending on the system used, but generally, it involves considering the rate at which heat is lost from the human body due to the combined effect of wind and temperature.
What are the The main air masses that affect the UK are:
The 4 main air masses that affect the UK are:
- Polar maritime: Cool and moist air originating from the North Atlantic Ocean.
- Tropical maritime: Warm and moist air originating from the Azores or the Caribbean Sea.
- Polar continental: Cold and dry air originating from northern Europe or Russia.
- Tropical continental: Warm and dry air originating from North Africa or the Mediterranean.
These air masses influence the weather patterns and temperatures experienced in the UK throughout the year.
https://www.rmets.org/sites/default/files/inline-images/Cirrus.png
Describe the various wind speed effects
Effect of Wind
Effect of Wind
20 -30 Mph - No effect on balance - drop in temp.
30 - 40 Mph - Effect balance - Movement impared - avoid exposed areas. e.g. edges, ridges, rough terrain.
40 - 50Mph - Walking arduous, blown off balance - hard work -saps energy.
50 - 60 Mph - Look for safest way off the hill.
60 + Don’t go out!
Describe the various wind speed effects
Effect of Wind
Effect of Wind
20 -30 Mph - No effect on balance - drop in temp.
30 - 40 Mph - Effect balance - Movement impared - avoid exposed areas. e.g. edges, ridges, rough terrain.
40 - 50Mph - Walking arduous, blown off balance - hard work -saps energy.
50 - 60 Mph - Look for safest way off the hill.
60 + Don’t go out!
Occluded fronts
The temperature drops as the warm air mass is occluded, or “cut off,” from the ground and pushed upward. Such fronts can bring strong winds and heavy precipitation. Occluded fronts usually form around mature low pressure areas
Occluded fronts
The temperature drops as the warm air mass is occluded, or “cut off,” from the ground and pushed upward. Such fronts can bring strong winds and heavy precipitation. Occluded fronts usually form around mature low pressure areas
What weather does a high pressure system bring?
What weather does a high pressure system bring?
In an anticyclone (high pressure) the winds tend to be light and blow in a clockwise direction (in the northern hemisphere). Also, the air is descending, which reduces the formation of cloud and leads to light winds and settled weather conditions.
What front brings the most rainfall?
cold front
As the warm air is pushed higher, the moisture it carries condenses and falls as rain. This is why a lot of heavy rain is produced along a cold front but once the cold air mass has come in this often abruptly changes to a clear spell of weather.
Weather fronts
Fronts are the principal cause of significant weather. Convective precipitation (showers, thundershowers, heavy rain and related unstable weather) is caused by air being lifted and condensing into clouds by the movement of the cold front or cold occlusion under a mass of warmer, moist air. If the temperature differences of the two air masses involved are large and the turbulence is extreme because of wind shear and the presence of a strong jet stream, “roll clouds” and tornadoes may occur.[22]
In the warm season, lee troughs, breezes, outflow boundaries and occlusions can lead to convection if enough moisture is available. Orographic precipitation is precipitation created through the lifting action of air due to air masses moving over terrain such as mountains and hills, which is most common behind cold fronts that move into mountainous areas. It may sometimes occur in advance of warm fronts moving northward to the east of mountainous terrain. However, precipitation along warm fronts is relatively steady, as in light rain or drizzle. Fog, sometimes extensive and dense, often occurs in pre-warm-frontal areas.[23] Although, not all fronts produce precipitation or even clouds because moisture must be present in the air mass which is being lifted.[1]
