Term
What are the losses of tornadoes compaired to hurricanes and why? |
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Definition
- less economic loss in a tornado but more fatalities (overall) - harder to mitigate tornadoes due to differences in forecasting - stronger winds - |
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Term
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Definition
- average about 483 km wide - violently rotating column of air extending between (and in contact with) a cloud and the earth's surface - rotates (not always counter- clockwise) - severe weather association - extremely high winds (can go to 130 m/s higher than cat 5 hurricanes) |
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Term
What are conditions leading to less deaths caused by hurricanes? |
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Definition
- better shelters - a more clean understanding of hurricanes - prediction measures - effective warning systems |
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Term
What is the difference between the Fujita scale and the E.F. scale? |
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Definition
Fujita- just wind speed E.F.- intensity scale - examines the relatively small gusts of wind |
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Term
How is wind strength measured? |
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Definition
mobile doppler radar - measures the speed of wind both coming toward and going away from it - if significant wind is going in both directions this indicates rotation |
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Term
Where do Tornadoes generally occur? |
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Definition
- can happen anywhere, but most frequent in north america due to the proximity to warmth, moisture and cold air and the North- South Orientation of the mountain ranges |
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Term
Where does the Warm-Moist air and cold air come from for North America? |
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Definition
Warm/Moist - Gulf stream current - Gulf of Mexico
Cold - arctic |
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Term
What is Tornado Alley and what are the conditions that caused it to earn that name? |
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Definition
- area in south central USA known for a high number of tornadoes - NE-SW orientation corresponding to strong fronts in central USA - it is where the air masses most frequently collide |
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Term
When do the most tornadoes occur? |
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Definition
- may - peak is in spring/summer in late afternoon - maximum temperature in the surface leads to destabilization |
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Term
What are the "ingredients" for a tornado? (what other natural event can lead to a tornado?) |
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Definition
- all form in thunderstorms Can form in.... - landfalling hurricanes - supercell thunderstorms - squall lines |
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Term
Required elements of a tornado? |
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Definition
- moisture source - unstable atmosphere (cool dry air --><-- warm moist air) - mechanism to trigger thunderstorm updraft= instability |
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Term
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Definition
- rate of change in temperature observed while moving upward in the atmosphere (will drop) |
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Term
Desribe how the atmosphere becomes unstable. |
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Definition
- air parcels are compact in volume and have high kinetic energy - as they rise, they expand and loose energy and so the temperature falls but due to latent heat release the cooling is offset by heat release of condensation until it changes to the the Moist Adiabatic lapse rate at this point the parcel begins to cool more slowly, indicating the air is saturated |
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Term
What are the triggers/ lifting mechanisms that cause the air parcels to rise and lead to thunderstorms? |
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Definition
Cold Front - cold air advances on warm air and plunges under - warm air has less water so clouds form and instability causing the particles to accelerate upward
Sea breeze Effect - cold ocean air penetrates over warm/moist land air - the air becomes unstable and rises (explains early spring storms in FL) |
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Term
What are the airmass thunderstorm stages? (Airmass dont produce tornades because the updrafts are suppressed by the weight of the water) |
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Definition
1. Cumulus (warm. bouyant plume with updrafs) 2. Mature (up and down drafts) 3. Dissipating (falling precipitation shuts off updrafts and the system self destructs) |
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Term
What are mesocyclones and how are they created? |
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Definition
- a small low pressure system with rotation -10% of the time becomes a tornado - when an updraft is imposed on an area of sheer, tilted rotation can occur and lead and lead the updraft away from the precipitation and lead to a supercell - will eventually turn into a mesocylcone |
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Term
How so we forecast tornadoes? |
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Definition
- recognize apparent formation patters |
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Term
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Definition
- dropped from supercell to stay on ground for about an hour - maximum warning was 15 minutes, extremely destructive |
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Term
Tornado Warning vs Tornado Watch |
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Definition
Warning - there is a tornado actually present in the area - max 1h warning Watch - happens 24-48 hours before a potential tornado |
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Term
Safety measures to take during a 'nado? |
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Definition
- move to shelter, basement - avoid windows and projectiles |
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