W08 Atmospheric Phenomena Flashcards
Funnel Cloud
A funnel-shape cloud of condensed water droplets, associated with a rotating column of wind and extending from the base of a cloud but not reaching the ground or a water surface.
Tornado
A funnel cloud that touches a land surface. (Identified by presence of bush)
Waterspout
A funnel cloud that touches a water surface. (Identified by presence of bush)
Thunderstorm
A local storm produced by a CB cloud and is always accompanied by lightning and thunder, usually with strong gusts of wind, heavy rain, and sometimes with hail.
What is to be reported when the vortex of a funnel-shape cloud does not (or may not) reach the ground?
Funnel cloud and its direction
When shall a tornado, waterspout, or funnel cloud be reported?
If it is within sight at the time of the observation
When shall a thunderstorm be recorded?
When thunder has been heard in the last 15 mins or overhead lightning has been seen in the past 15mins and local noise is such that it might prevent the observer from hearing thunder.
What time should be recorded for the beginning of a thunderstorm?
The time of the earliest occurrence that indicates thunderstorm activity at the station.
What time should be recorded for the end of a thunderstorm?
When it is no longer possible to report thunderstorm activity at the station for 15 minutes.
How are the beginning and end times for tornadoes, water spouts, and funnel clouds determined?
By when you first see them, and then can no longer see them. If the bush goes out of view, the tornado ends and a funnel cloud begins.
Priority of Remarks
- General Weather Remarks2. Snowfall3. Rainfall4. Hail Size5. Runway Visual Range (RVR)
Char. of PrecipitationNot occurring at the time of observation, but is expected to begin again soon
OCNL -SHRAINTMT -RA
Char. of PrecipitationIntermittent precipitation precipitation occurring at time of observation.
-RA INTMT
TS
Thunderstorm
Thunderstorm Abbrev.
TS
Funnel Cloud Abbrev.
FC
FC
Funnel cloud
Tornado Abbrev.
FC+
FC+
Tornado/waterspout
Waterspout Abbrev.
FC+
In which cases is there a 15 minute ‘leeway’ for begin/end times?
Thunder, intermittent or showery precipitation, or obstruction to vision.
Order of priority for column 32
-Tornado, water spout, funnel cloud-Thunderstorm-Liquid precipitation-Freezing precipitation-Frozen precipitation (Precipitations in order of decreasing intensity)-Obstruction to vision-Additional and vicinity phenomena
What must be recorded in the remarks column when reporting a tornado or waterspout?
Direction from station and the direction toward which it is moving
What must be recorded in the remarks column when reporting a tornado or waterspout that has been reported by the public?
Location with respect to the station or city, direction toward which it is moving, and the time at which it was observed
LTGCG
Lightning cloud to ground
Lightning cloud to ground Abbrev
LTGCG
LTGCC
Lightning cloud to cloud
Lightning cloud to cloud abbrev
LTGCC
LTGIC
Lightning in cloud
Lightning in cloud abbrev
LTGIC
LTNG
Lightning (Type unkown)
What is to be recorded when the type of lightning is not known?
LTNG
What must be recorder when lightning is observed?
FrequencyTypeDirection from station
If two or more types of lightning are observed, how is this reported?
LTGCCCG, LTGCGCCIC
Abbreviations for lighting frequency
OCNL, FRQ, CONTUS
What shall be recorded on the 2322 as unusual weather?
Damage to life or property by:-frost-high wind, tornadoes or hail-thickness of ice (during freezing precipitation)-Floods or droughts-Other items of considerable value for climatological purposes (severe lightning)
Where on the 2322 shall unusual weather be recorded?
Column 1, and if there is not enough room, on the back of the 2322 with notes to this effect on the front.
Precipitation
Any product of the condensation of atmospheric water vapour that is deposited on the earth’s surface is a type of precipitation.
What are the three forms of precipitation?
LiquidFreezingFrozen
Liquid precipitation
Water drops at 0 degrees or greater
Freezing precipitation
Water drops at -0.1 degrees or less. Drops freeze on the ice accretion indicator.
Frozen precipitation
Solid particles of crystals of ice.
What are the three characters of precipitation
Showery, continuous, intermittent.
Showery precipitation
-Falls from cumuliform cloud-Begins and ends abruptly-Usually has a short duration-rapidly fluctuates in intensity-sky brightens between showers
Continuous precipitation
-When there is no break in precipitation for at least an hour-When there is no break in precipitation since the beginning of the hour preceding the time of observation.
DZ
Drizzle:-Liquid water particles
RA
Rain: Precipitation of liquid water particles > 0.5mm falling in widely scattered drops.
FZDZ
Freezing drizzle: drizzle that freezes on impact with the ground or other objects near the earth’s surface. To be reported when temperature 0.1 degrees or less.
FZRA
Freezing rain: rain that freezes on impact with the ground or other objects near the earth’s surface. To be reported when temperature 0.1 degrees or less.
SN
Snow: mainly hexagonal crystals that are usually branched. At a temperature higher than about -5 degrees, the crystals become clustered to form flakes.
GS
Snow pellets:-White and opaque ice particles-spherical or conical-2-5mm diameter-brittle and easily crushed-bounce and break up on hard ground-always occur in showers*GS is also used to report small hail (
At what temperature do snow pellets occur?
Around 0 degrees
SG
Snow grains: -very small white, opaque ice particles-flat and elongated-
PL
Ice pellets:-transparent or translucent ice pellets-spherical, rarely conical-5mm diameter or less-bounce and make sound on impact-2 types: a and b
Ice pellets type a
Frozen raindrops or snowflakes that melted then refroze that usually fall continuously
Ice pellets type b
-Pellets of snow encased in a thin ice layer-droplets intercepted by the pellets-water resulting from partial melting of the pellets-usually fall in showers
GR
Hail: Small balls or pieces of transparent ice with a diameter of 5-50mm or sometimes more which fall separately or fused into irregular lumps.