13-2 weather fronts

Which of the following represents the slope of a warm front? A) 1 mile vertically to 150 miles horizontally B) 1 mile vertically to 500 miles horizontally C) 1 mile vertically to 10 miles horizontally D) 1 mile vertically to 50 miles horizontally

A) 1 mile vertically to 150 miles horizontally

Which type of frontal passage is associated with a relatively narrow band of precipitation? A) A cold front B) A warm front C) A stationary front D) None of the above

A) A cold front

Which weather change accompanies the passage of a cold front in the Northern Hemisphere? A) A line of cumulonimbus clouds B) Wind shift from northeast, clockwise to southwest C) Steady precipitation, gradually increasing in intensity D) Steady dropping of barometric pressure

A) A line of cumulonimbus clouds

In the Northern hemisphere which semicircle of a hurricane is the navigable semicircle? A) Left B) Back C) Front D) Right

A) Left

Your present weather is sunny with a steady barometer. A low swell approaches your vessel from the south with crests passing at relatively long periods of about four per minute. This usually indicates __________. A) a tropical cyclone south of your vessel B) a hurricane about 100 miles south of your vessel and heading in your direction C) a warm front from the south D) an extra-tropical cyclone

A) a tropical cyclone south of your vessel

Which of the following causes a frontal thunderstorm? A) a warm air mass rising over a cold air mass B) pronounced local heating C) wind being pushed up a mountain D) an increased lapse rate caused by advection of warm surface air

A) a warm air mass rising over a cold air mass

Clouds are classified according to their __________. A) altitude and how they were formed B) moisture content C) size D) location in a front

A) altitude and how they were formed

In a cyclone the lowest pressure is found in the __________. A) center B) warm front C) outer edge D) cold front

A) center

A series of brief showers accompanied by strong, shifting winds may occur along or some distance ahead of a(n) __________. A) cold front B) upper front aloft C) cyclone D) occluded front

A) cold front

To avoid error you should read the scale of an aneroid barometer with your eye placed __________. A) directly in front of the pointer B) to the left of the pointer C) slightly above the meniscus D) to the right of the pointer

A) directly in front of the pointer

When a warm air mass is adjacent to a cold air mass, the separation line between the two is called a(n) __________. A) front B) equipotential line C) isotherm D) isobar

A) front

The FIRST indications a mariner will have of the approach of a warm front will be __________. A) high clouds gradually followed by lower thicker clouds B) fog caused by the warm air passing over the cooler water C) large cumulonimbus clouds building up D) low dark clouds with intermittent rain

A) high clouds gradually followed by lower thicker clouds

When drawing a weather map and an isobar crosses a front, the isobar is drawn __________. A) kinked and pointing away from the low B) kinked and pointing towards the high for a warm front only C) kinked and pointing towards the low D) perpendicular to the front

A) kinked and pointing away from the low

You are steaming west in the North Atlantic in an extratropical cyclonic storm, and the wind is dead ahead. According to the law of Buys Ballot, the center of low pressure lies to the __________. A) north B) east C) south D) west

A) north

According to Buys Ballot's law, when an observer in the Northern Hemisphere experiences a northwest wind, the center of low pressure is located to the __________. A) northeast B) west-southwest C) northwest D) south-southeast

A) northeast

A cyclone in its final stage of development is called a(n) __________. A) occluded cyclone or occluded front B) tornado C) polar cyclone D) anticyclone

A) occluded cyclone or occluded front

Tropical cyclones do not form within 5° of the Equator because __________. A) of negligible Coriolis force B) it is too hot C) it is too humid D) there are no fronts in that area

A) of negligible Coriolis force

Cyclones tend to move __________. A) parallel to the isobars in their warm sectors B) parallel to the line of the cold front C) perpendicular to the isobars in their warm sectors D) perpendicular to the line of the cold front

A) parallel to the isobars in their warm sectors

Your facsimile prognostic chart indicates that you will cross the cold front of a low pressure system in about 24 hours. You should __________. A) prepare for gusty winds, thunderstorms, and a sudden wind shift B) expect to see cirrus clouds followed by altostratus and nimbostratus clouds C) alter course to remain in the navigable semicircle D) expect clear weather, with steady winds and pressure, until the front passes

A) prepare for gusty winds, thunderstorms, and a sudden wind shift

As it approaches, a typical warm front will bring __________. A) rising temperatures and falling barometric pressure B) rising barometric pressure and temperatures C) falling temperature and pressure D) falling temperatures and rising pressure

A) rising temperatures and falling barometric pressure

The belt of light and variable winds between the westerly wind belt and the northeast trade winds is called the __________. A) subtropical high pressure belt B) polar frontal zone C) intertropical convergence zone D) doldrum belt

A) subtropical high pressure belt

You can expect frontal activity when two air masses collide and __________. A) there are significant differences between the temperature of each air mass B) there are differences in how they track along the jet stream C) their barometric pressures and temperatures are the same D) there are no significant differences between their temperatures and moisture content

A) there are significant differences between the temperature of each air mass

How does visibility change after the passage of a cold front? A) visibility will improve rapidly B) visibility will slightly improve C) visibility does not change D) visibility becomes poor

A) visibility will improve rapidly

When a warm air mass overtakes and replaces a cold air mass, the contact surface is called a(n) __________. A) warm front B) occluded front C) cold front D) line squall

A) warm front

Which of the following statements concerning frontal movements is TRUE? A) A warm front usually has more violent weather associated with it than a cold front. B) A cold front generally passes faster than a warm front. C) The temperature rises after a cold front passes. D) The barometric pressure rises when a warm front passes

B) A cold front generally passes faster than a warm front.

What weather change accompanies the passage of a cold front in the Northern Hemisphere? A) Wind shift from northeast clockwise to southwest B) A line of cumulonimbus clouds C) Steady precipitation, gradually increasing in intensity D) Steady dropping of barometric pressure

B) A line of cumulonimbus clouds

What type of clouds are associated with a cold front? A) Altostratus and fracto-cumulus B) Cumulus and cumulonimbus C) Cirrus and cirrostratus D) Altostratus and cirrus

B) Cumulus and cumulonimbus

The direction of prevailing winds in the Northern hemisphere is caused by the __________. A) Arctic cold fronts B) Earth's rotation C) Gulf Stream D) magnetic field at the North Pole

B) Earth's rotation

Which wind pattern has the most influence over the movement of frontal weather systems over the North American continent? A) Dominant southwesterly flow B) Prevailing westerlies C) Northeast trades D) Subpolar easterlies

B) Prevailing westerlies

On a working copy of a weather map what color is the line that represents a warm front? A) Alternating red and blue B) Red C) Purple D) Blue

B) Red

The navigable semicircle of a tropical storm in the South Indian Ocean is located on which side of the storm's track? A) Rear B) Right C) Front D) Left

B) Right

The fog produced by warm moist air passing over a cold surface is called __________. A) conduction fog B) advection fog C) frontal fog D) radiation fog

B) advection fog

The atmosphere in the vicinity of a high pressure area is called a(n) __________. A) occluded front B) anticyclone C) cold front D) cyclone

B) anticyclone

When crossing a front how do isobars tend to change? A) change from sharp bends within the air mass to smooth curves at the front B) change from smooth curves within the air mass to sharp bends at the front C) pass smoothly across the front with no change D) become closer together at the front and pass through in straight lines

B) change from smooth curves within the air mass to sharp bends at the front

A line of clouds, sharp changes in wind direction, and squalls are most frequently associated with a(n) __________. A) warm sector B) cold front C) warm front D) occluded front

B) cold front

Cumulonimbus clouds are most likely to accompany a(n) __________. A) high pressure system B) cold front C) warm front D) occluded front

B) cold front

Which of the following causes the development of an occluded front? A) high pressure area B) cold front overtaking a warm front C) low pressure area D) area of calm air

B) cold front overtaking a warm front

Which of the following is a boundary between two air masses? A) isobar B) front C) continent D) lapse rate

B) front

The steepness of a cold front depends on __________. A) the precipitation generated by the front B) its velocity C) the direction of wind around the front D) the temperature of the air behind the front

B) its velocity

As a warm front approaches how does barometric pressure change? A) pressure is steady B) pressure falls C) pressure is uncertain D) pressure rises

B) pressure falls

When a cold air mass and a warm air mass meet, and there is no horizontal motion of either air mass, it is called a(n) __________. A) cold front B) stationary front C) occluded front D) warm front

B) stationary front

When a warm air mass overtakes a cold air mass, the contact surface is called a __________. A) line squall B) warm front C) water spout D) cold front

B) warm front

Fog is most commonly associated with a(n) __________. A) anticyclone B) warm front at night C) low pressure area D) cold front in the spring

B) warm front at night

When does a weather front exist? A) when two lows are separated by a ridge of higher pressure B) when air masses of different temperatures meet C) when multiple clouds create a differential in air density D) when air masses of the same temperature meet

B) when air masses of different temperatures meet

Which of the symbols shown in illustration D018NG below represents a warm front? A) A B) B C) C D) D

C) C

Which condition will occur after a cold front passes? A) Pressure decreases B) Temperature rises C) Humidity decreases D) Stratus clouds form

C) Humidity decreases

A phenomenon where the atmospheric pressure is higher than that of other surrounding regions is called __________. A) the "doldrums" B) a low front or an occluded front C) a high pressure area; an anticyclone; or a "high" D) the "trade winds"

C) a high pressure area; an anticyclone; or a "high"

Steady precipitation is typical of __________. A) high pressure conditions B) coming cold weather conditions C) a warm front weather condition D) scattered cumulus clouds

C) a warm front weather condition

The fog most commonly encountered at sea is called __________. A) radiation fog B) conduction fog C) advection fog D) frontal fog

C) advection fog

In the Northern Hemisphere, what do winds veering sharply to the west or northwest with increasing speed indicate? A) stationary front exists B) high pressure center has passed C) cold front has passed D) low pressure center is approaching

C) cold front has passed

How does the temperature change with the passage of an occluded front? A) remains about the same B) drops rapidly C) depends on whether warm type or cold type occlusion D) rises rapidly

C) depends on whether warm type or cold type occlusion

Cumulonimbus clouds can produce __________. A) dense fog and high humidity B) clear skies with the approach of a cold front C) gusty winds, thunder, rain or hail, and lightning D) a rapid drop in barometric pressure followed by darkness

C) gusty winds, thunder, rain or hail, and lightning

In the Northern Hemisphere, an area of counterclockwise wind circulation surrounded by higher pressure is a __________. A) high B) warm front C) low D) cold front

C) low

As a cold front passes how do the pressure and the winds change? A) pressure drops and winds become gusty B) pressure drops and winds become variable C) pressure rises and winds become gusty D) pressure rises and winds become variable

C) pressure rises and winds become gusty

The type of fog that occurs on clear nights with very light breezes and forms when the earth cools rapidly ? A) frontal fog B) advection fog C) radiation fog D) convection fog

C) radiation fog

Swells that have outrun the storm are produced in the __________. A) directly ahead on the storms projected track B) rear C) right front quadrant D) left front quadrant

C) right front quadrant

What happens to the barometric pressure after a cold front passes? A) drops, and the temperature rises B) drops, and the temperature drops C) rises, and the temperature drops D) rises, and the temperature rises

C) rises, and the temperature drops

According to Buys Ballot's law, when an observer in the Northern Hemisphere experiences a northeast wind the center of low pressure is located to the __________. A) west-southwest B) northwest C) south-southeast D) northeast

C) south-southeast

You are steaming eastward in the North Atlantic in an extratropical cyclonic storm and the wind is dead ahead. According to the law of Buys Ballot, the center of the low pressure lies __________. A) astern of you B) to the north C) to the south D) ahead of you

C) to the south

You are steaming west in the South Atlantic in an extratropical cyclonic storm, and the wind is dead ahead. According to the law of Buys Ballot, the center of low pressure lies __________. A) to the north of you B) dead ahead of you C) to the south of you D) dead astern of you

C) to the south of you

How can you estimate the position of a tropical storm's center? A) With a radio weather bulletin or weather fax B) using shipboard radar C) observe the wind direction and apply Buys Ballot's law D) All of the above

D) All of the above

What is true about a front? A) A front is a boundary between two air masses. B) There are abrupt temperature differences on opposite sides of a front. C) The pressure tendencies are different on opposite sides of a front. D) All of the above

D) All of the above

On a working copy of a weather map what color is the line that represents a stationary front? A) Red B) Blue C) Purple D) Alternating red and blue

D) Alternating red and blue

Which type of front forms when a cold front overtakes and forces a warm front upwards? A) A warm front B) A stationary front C) A cold front D) An occluded front

D) An occluded front

On a working copy of a weather map, a cold front is represented by what color line? A) Purple B) Alternating red and blue C) Red D) Blue

D) Blue

What enables you to estimate the bearing of a storm's center? A) An educated guess B) The left-hand rule C) Pascal's Law D) Buys Ballot's Law

D) Buys Ballot's Law

Which statement is TRUE when comparing cold and warm fronts? A) Cold fronts are milder and last longer. B) They are very similar with the exception of wind direction. C) Warm fronts are more violent and of longer duration. D) Cold fronts are more violent and of shorter duration.

D) Cold fronts are more violent and of shorter duration.

Which of the symbols shown in illustration D018NG below represents an occluded front? A) A B) B C) C D) D

D) D

Which type of weather could you expect soon after seeing "hook" or "comma" shaped cirrus clouds? A) Clearing with the approach of a cold front B) The formation of a tropical depression C) Continuing fog and rain D) Rain with the approach of a warm front

D) Rain with the approach of a warm front

What is typical of warm front weather conditions? A) A wind shift from southwest to northwest B) Scattered cumulus clouds C) An increase in pressure D) Steady precipitation

D) Steady precipitation

When cold air displaces warm air you have a(n) __________. A) warm front B) stationary front C) occluded front D) cold front

D) cold front

A generally circular low pressure area is called a(n) __________. A) anticyclone B) occluded front C) cold front D) cyclone

D) cyclone

The first indications a mariner will have of the approach of a warm front will be __________. A) low dark clouds accompanied by intermittent rain B) large cumulonimbus (thunderclouds) building up C) fog caused by the warm air passing over the cooler water D) high cirrus clouds gradually changing to cirrostratus and then to altostratus

D) high cirrus clouds gradually changing to cirrostratus and then to altostratus

Brief, violent showers frequently accompanied by thunder and lightning are usually associated with __________. A) winds shifting counterclockwise in the Northern Hemisphere B) passage of a warm front C) stationary high pressure systems D) passage of a cold front

D) passage of a cold front

Cumulus clouds that have undergone vertical development and have become cumulonimbus in form, indicate __________. A) clearing weather B) an approaching hurricane or typhoon C) that a warm front has passed D) probable thunderstorm activity

D) probable thunderstorm activity

How is an occluded front represented on a weather map? A) dashed blue line B) blue line C) alternate red and blue line D) purple line

D) purple line

If an observer in the Northern Hemisphere faces the surface wind, the center of low pressure is to his _________. A) right, slightly in front of him B) left, slightly in front of him C) left, slightly behind him D) right, slightly behind him

D) right, slightly behind him

Which of the following typically happens to the barometric pressure after a cold front passes? A) fluctuates B) remains the same, with clouds forming rapidly C) remains the same D) rises, often quite rapidly, with clearing skies

D) rises, often quite rapidly, with clearing skies

According to Buys Ballot's Law, when an observer in the Southern Hemisphere experiences a northwest wind, the center of the low pressure is located to the __________. A) east-southeast B) east-northeast C) west-southwest D) south-southwest

D) south-southwest

A cold front moving in from the northwest can produce __________. A) lengthy wet weather B) increasing cloud cover lasting for several days C) low ceilings with thick cirrus clouds D) thunderstorms, hail, and then rapid clearing

D) thunderstorms, hail, and then rapid clearing