Meteorology #1 Flashcards
Tropical Cyclones are considered to be ‘tropical disturbances’, list four characteristics with regards to the classification and development of a Tropical Cyclone.
Non-frontal low pressure system that develops over warm waters (=>26ºC). Usually develop between 5º to 20º N or S latitude, and can develop as far as 30º. Classified as a TC when the maximum mean winds around the centre are => 34kts, and classified as a Severe TC when the winds are => 64kts.
Describe factors regarding Cold Fronts.
The weather after the front tends to stream showers in the colder, unstable westerly airmass. Move from west to east (southern hemisphere). Pressure tends to fall ahead of the front then rise following the front.
What are hazards associated with Thunderstorms?
Heavy rain. Tornados. Microburst. Hail. High surface wind gusts. Inaccurate instrument readings. Lighting. Severe clear icing. Significant visibility reduction. Severe turbulence. Low level wind sheer.
What is the reason for the spreading out of the cumulonimbis cloud top?
Cloud reaches the tropopause which is a stable layer and therefore cloud is likely to lack sufficient energy to penetrate the layer.
In order from the surface of the Earth, list the layers of the atmosphere.
Troposphere -> Stratosphere -> Mesosphere -> Thermosphere -> Exosphere.
What is the effects of virga on an aircraft on a glideslope?
The presence of cumulus cloud and verga indicate microburst. On approach, the aircraft experiences a strong headwind, it then experiences downburst followed by a strong tailwind.
Describe the orographic cloud formation process.
Uplift is caused by a physical barrier, such as terrain, causing moist air to rise above a condensation point.
Descirbe the convective cloud formation process.
Uplift caused by air heated by the Earth’s surface rising in the form of thermal currents or bubbles.
Descirbe the widespread ascent cloud formation process.
Results from the interaction of the air masses, or the movement of a cold air mass forcing warm air to rise ahead of it - cold front interacting with warmer air.
Descirbe the turbulence/mechanical cloud formation process.
Occurs when air flow is broken into a series of eddies as it moves over uneven surfaces.
Descirbe the conductive cooling cloud formation process.
Moist air cooled by the Earth’s surface and fixed with light wind causing low level fog.
Describe Radiation fog.
When moist air is cooled below the dew point temperature when it comes into contact with land cooling due to radiational cooling overnight.
What are the ideal conditions for Radiation fog?
High relative humidity at low levels. Cloudless/near cloudness sky to allow large heat loss. Light winds to promote weak mixing and cooling to a greater depth of atmosphere.
How can Radiation fog be dissipated?
Solar heating and wind.
Describe Advection fog.
Like radiation fog - Mostly forms as an airmass is cooled from below, the difference is that the moist air flows over a cold surface.
