Thunderstorms Flashcards
What are 3 requirements for a thunderstorm to form
1-Instability throughout a layer at least 10000ft deep, ELR > SALR
2-a form of lifting/trigger action
3-high moisture content
What 5 ways is air lifted to create a thunderstorm
1-convection
2-orographic uplift
3-advection
4-convergent uplift
5-dynamic lifting because of the presence of a frontal zone
What 2 types of thunderstorms are there and when/where do they occur, what is their trigger action
1-heat/air mass TS: occurs in mid latitudes is summer, and at equator all year long, triggered by convergence, Convection, orographic uplift and advection
2-frontal TS: mid lat cyclone cold fronts/dry lines, triggered by frontal lifting
Development/Cumulus Stage
1-what happens in this stage
2-how do the cloud forms continue to rise
1-parcels of warm humid air rise and cool to form clusters of puffy white CU
2-release of latent heat from freezing water droplets and the growth of snow crystals and hailstones
Mature Stage of TS
1-how are downdraughts formed in this stage
2-What marks the beginning of this stage
3-what is found at the top of the
cloud
4-what is a gust front
5-what type of wind and cloud can be associated with a gust front
1-water droplets grow large enough to fall, dragging air down with them
2-onset of Precip and downdraughts
3-ice crystals
4-cold air flowing out from a downdraught in all directions, but tending to lead the storm along it’d line of movement
5-windshear and roll clouds
Dissipating Stage
1-what happens to the airflow
2-what kind of Precip occurs
3-what can cause the cloud to dissipate/spread out and what cloud forms
1-becomes only downdraughts
2-light drizzle
3-subsiding air, SC
1-What is a squall line
2-what weather is associated with it
1-a line of TS that can from along/ahead of a cold front
2-heavy precip, hail, frequent lightning, strong straight line winds, possibly tornadoes
What area and stage is icing found in a TS
At or above the freezing level in the areas of heaviest turbulence during the mature Stage
What actions should be taken in the event of TS penetration
1-tighten safety harness
2-calculate course to pass through storm in min time
3-set power for turbulence penetration speed
4-turn up cockpit lights
5-maintain constant alt
Don’t turn back once in TS
What is a Tropical Revolving Storm referred to as in:
1-the Indian Ocean and South Pacific
2-Western Atlantic and Eastern Pacific
3-Western Pacific
1-cyclone
2-hurricane
3-typhoon
1-what is a Tropical Revolving Storm
2-Where do they form
1-Á Non-frontal system characterized by LP centre, spiral rain bands and strong winds
2-in very moist air in ocean regions
Characteristics of TRS
1-what precip is associated with it
2-what seasons do they occur
3-where do they develope
1-torrential rain
2-late summer and early autumn
3-over warm oceans
Areas of formation and associated terms of TRS
1-where do they start to form
2-why don’t they occur near the equator
3-what happens to them over land as well as outside 30°N/S
4-What circulation cell do they develope in
5-what wind belt do they occur and which direction do they move
6-where and at what temp do they develope
1-at the ITCZ
2-lack of Coriolis Force
3-they dissipate
4-hadley cell
5-occur in Tropical Easterly wind belts and move E - W
6-over oceans with temps higher than 26°C
Conditions necessary for formation of TRS
1-what happens to air mass properties from large scale evaporation
2-what causes the intense low pressure on the surface and what effect does the Tropical Jet Stream have on it
1-becomes hot, humid and unstable
2-hot air rising, TJS causes upper air divergence intensifying LP on SFC
