Exam 3 Flashcards
In numerical weather prediction, forecast and errors may come from errors in ________ and ________.
Initial condition; model
Three stages of an ordinary cell thunderstorm.
- Cumulus stage
- Mature stage
- Dissipating stage
What happens to the warmer air mass when it collided with a colder air mass?
Forced to lift
The difference of a hurricane and a mid-latitude cyclone in the core, in terms of temperature and motion are:
Cold updraft in mid latitude cyclone, warm downdraft in hurricane
What type of clouds (in order) would you see
Cirrus, cirrostratus, altostratus, nimbostratus
Six steps of mid-latitude cyclones development based on the Polar Front Theory.
- Stationary front
- Frontal wave
- Open wave
- Initial occlusion
- Advanced occlusion
- Cut off cyclone
What happens to a surface low of an upper air low lies directly above it?
Weakens
On a weather map, the transition zone between two air masses with sharply contrasting properties is marked by
A front
The development or strengthening of a middle latitude cyclone storm system
Cyclogenesis
The rising of warm air up and over cold air
Overrunning
An air mass is characterized by similar properties of ________ and ________ in any horizontal direction.
Temperature; moisture
For cyclogenesis to occur along a frontal wave, the winds aloft directly above the wave should be
Diverging
Atmospheric short waves usually move _____to_____ at a speed that is ________ than longwaves.
West to east; faster
According to the model of the life cycle of a wave cyclone, the storm system is normally most intense
When the system first becomes occluded.
What type of air mass would be responsible for hot, dry summer weather in southern Arizona? (c/m and T/P)
cT
A stationary front does not move because
The winds blow parallel to the front
Developing low pressure areas generally have ________ air near the surface and ________ air aloft.
Converging; diverging
Which of the following is not correct concerning a warm front?
It has warm air ahead (in advance) of it.
One would expect a cP air mass to be
Cold and dry.
What type of air mass would be responsible for snow showers on the western slopes of the Rockies?
mP
When an upper-level low lies directly above a surface low:
The surface low will probably weaken.
A true cold front on a weather map is always
Followed by cooler air.
If the flow of air into a surface low pressure area is greater than the divergence of air aloft, the surface pressure in the center of the low will
Increase
What type of weather front would be responsible for the following weather forecast: “increasing cloudiness and warm today with the possibility of showers by this evening, turning much colder tonight, with winds southwesterly becoming gusty and shifting to northwesterly by tonight”?
Cold front
A good source region for an air mass would be
Generally flat areas of uniform composition with light surface winds
When comparing an “average” cold front to an “average” warm front, which of the following is not correct?
Generally, precipitation covers a much broader area with a cold front
In the polar front theory of a developing wave cyclones energy for the storm is usually derived from all but one of the following:
Heat energy stored in the ground
The type of weather system known as a “mid latitude cyclone” cannot form over the tropical ocean because
Surface temperatures contrasts are not large and the Coriolis force is weak in the tropics.
What type of weather front would be responsible for the following weather forest: “increasing high cloudiness and cold this morning, clouds increasing and lowering this afternoon with a chance of snow or rain tonight, precipitation ending tomorrow morning, turning much warmer, winds light easterly today becoming southeasterly tonight and southwesterly tomorrow”?
Warm front
For a surface storm system to intensify, the upper-level low (or trough) should be located to the _____ of the surface low.
West
In winter, which sequence of clouds would you most likely expect to observe as a warm front with precipitation approaches your location?
Cirrus, cirrostratus, altostratus, nimbostratus
The greatest contrast in both temperature and moisture will occur along the boundary separating which air masses?
mT and cP
A warm, moist air mass that forms over water is called
mT
When two air masses collide at a front, one air mass is pushed upward by the other. This is because
One air mass is denser than the other
Before the passage of a cold front, the pressure normally _____, and after the passage of a cold front, the pressure normally _____.
Drops; rises
Lake-effect snows are best developed around the Great Lakes during
Late fall and early winter when cold, dry polar air moves over the relatively warm water
Which of the following is not correct concerning a cold front?
It is colored purple on a weather map.
Suppose that where you live in the middle of January is typically several degrees warmer than the rest of the month. If you forecast this January thaw for the middle of next January, you would have made a
Climatological forecast
Which of the following explain why it is possible to see clouds on satellite photos taken at night?
The clouds emit infrared light
The greatest improvement and forecasting skill during the past decade has been
In the lead time for watches and warnings of severe storms.
Weather forecast predicts that the future weather will be the same as the present weather is called
A persistence forecast
A weather warning indicates that
Hazardous weather is either imminent or occurring within the forecast area
An accurate forecast
May or may not show skill.
What position would you expect to hear the following 12 hour forecast: “cloudy and cold this morning with snow this afternoon and tonight”? (MLC)
Above the mid-latitude cyclone (triangular) tip
A polar orbiting satellite would provide a more detailed view of a severe thunderstorm than a geosynchronous satellite.
True
A weather forecast for the immediate future that employs the trend messages is called
Nowcasting
The forecast method that compares past weather maps and weather patterns to those of the present is
The analogue method
By examining the surface map, the movement of a surface low-pressure area can be predicted based upon the
All of the above