Meteorology Flashcards
The different air masses that form a depression?
Global meteorological systems
Buildup:
Depression
the tropical warm air is wedged in between warm and cold fronts
before/after warm front: cold, HIGH
in warm sector: warm, LOW
Weather phenomena when evaluating a weather situation?
- Temperature (up, down, constant?)
- Air pressure (up, down, constant?)
- Wind force (inrease, unchanged?)
- Wind direction (backing, veering?)
- Wind waves (decreasing, increasing?)
- Clouds.
- Precipitation.
- Visibility (improving, deteriorating)
Cloud classification?
Buildup:
Warm front
Buildup:
Cold Front
Depression passing: phenomena
Phenomena warm front approaching
- Wind: increases and backs
- Cloud: sequence of cirrus, cirrostratus
altostratus, nimbostratus and low stratus - Weather: rain becomes heavier and more continuous
- Visibility: deteriorates slowly as rain gets heavier
- Pressure: falls at increasing rate
- Temperature: little change
Weather phenomena:
warm front passes
- Wind: veers
- Clouds: nimbostratus
- Weather: rain stops or turns to drizzle
- Visibility: deteriorates
- Pressure: stops falling
- Temperature: rises
Weather phenomena:
warm sector
- Wind: steady direction
- Cloud: stratus, stratocumulus
- Weather: occasional drizzle or light rain
- Visibility: moderate or poor (fog possible)
- Pressure: falls if depression deepening otherwise steady
- Temperature: little change
Weather phenomena:
cold front approaching
- Wind: backs & increases close to front
- Cloud: stratus en stratocumulus, thickening
nimbostratus - Weather: heavy rain near front
- Visibility: moderate to poor
- Pressure: falls near front
- Temperature: little change
Weather phenomena:
cold front passes
- Wind: sudden veer often with gusts
- Clouds: cumulonimbus (sometimes stratus)
- Weather: heavy rain, perhaps hail and thunder
- Visibility: poor in rain
- Pressure: sudden rise
- Temperature: sudden fall
Weather phenomena:
behind cold front
- Wind: probably backs a little then direction steady; stronger & gusty
- Cloud: often total clearance; cumulus develops afterwards
- Weather: usually fine for an our or two, then showers.
- Visibility: very good (except in shower)
- Pressure: rise gradually levels off
- Temperature: little change
Cross section:
warm / cold front
Cold front occlusion
Global circulation patterns
What determines wind waves?
a. the wind strength
b. the duration of the wind
c. the wind direction: onshore or offshore. (NW or SE above the Wadden
Islands!)
d. depth and expanse of water (fetch)
Wind force conversion
(rules of thumb)
(kts / 5) + 1 = BFT
m/s * 2 = kts
Wind force depends on?
- gradient
- curvature of isobars
- latitude on earth (lower latitudes: stronger with for equal gradient)
- friction (sea ./. land)
Swell: definition?
- caused by wind further away
- old sea state
right ./. left half of depression
- right half: veering
- left half: backing
=> fronts (and occlusion point) are situatied on right half => this is where the weather phenomena are
=> left half is more evenly
Trough: definition
“mini coldfront”
similar characteristics; bent isobars
Troposphäre ./. Tropopause
Weather (depression) developing in westwind Trift
Function of depression: move warm, tropical air north and cold, polar air masses south (“Mischmaschine) -> Polarfront
Wettergeschehen ideales Tief
Okklusionspunkt: where warm and cold front originate
Fully occluded: purpose of distributing polar/tropical air masses accomplished
