What is the approximate speed of a 40 knot wind expressed in m/sec ?
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Where in central Europe are the highest wind speeds to be found ?
If Paris reports a wind of 19015KT on the METAR what wind velocity would you expect to encounter at a height of 2000 feet above the ground ?
If paris reports a wind of 08010kt on metar what wind velocity would you expect to encounter at a height of 2000 feet above ground Just below tropopause. values to be used in examinations over sea wind speed in friction layer decrease 30% wind in friction layer blows across isobars towards low pressure angle between wind direction isobars changes 10° over land wind speed in friction layer decrease 50% wind in friction layer blows across isobars towards low pressure angle between wind direction isobars changes 30°. 
If paris reports a wind of 16020kt on metar what wind velocity would you expect to encounter at a height of 2000 feet above ground Just below tropopause. values to be used in examinations over sea wind speed in friction layer decrease 30% wind in friction layer blows across isobars towards low pressure angle between wind direction isobars changes 10° over land wind speed in friction layer decrease 50% wind in friction layer blows across isobars towards low pressure angle between wind direction isobars changes 30°. 
If paris reports a wind of 30012kt on metar what wind velocity would you expect to encounter at a height of 2000 feet above ground Just below tropopause. values to be used in examinations over sea wind speed in friction layer decrease 30% wind in friction layer blows across isobars towards low pressure angle between wind direction isobars changes 10° over land wind speed in friction layer decrease 50% wind in friction layer blows across isobars towards low pressure angle between wind direction isobars changes 30°. 
Which of following true of a land breeze It blows from land to water. land breeze during night (land cold sea warm) during day situation reverses the wind will blow from sea (sea breeze) . Question 127-8
An aircraft approaching under visual flight rules an airfield whose runway parallel to coast when downwind over sea airfield on right what wind effect should be anticipated on final approach and landing during a sunny afternoon Crosswind from right. during a sunny afternoon sea breeze likely to occur if coast runway are aligned east/west a right hand circuit would mean runway 27 in use sea to north land to south at touch down northerly sea breeze would be from right. Question 127-9
An aircraft approaching under visual flight rules an airfield northern hemisphere whose runway parallel to coast when downwind over sea airfield on left what wind effect should be anticipated on final approach and landing during a sunny afternoon Crosswind from right. during a sunny afternoon sea breeze likely to occur we should expect a crossing from left on final approach landing . Question 127-10
When will surface wind in a metar record a gust factor When gusts are at least knots above mean wind speed. during a sunny afternoon sea breeze likely to occur we should expect a crossing from left on final approach landing . Question 127-11
Select from map average wind the route zurich rome at fl110 303 When gusts are at least knots above mean wind speed. a feather corresponds to 10 kt if you look at wind close to rome it comes approximately from 235° average wind 230°/10 kt. Question 127-12
Select from map average wind the route athens geneva at fl 160 304 When gusts are at least knots above mean wind speed. on chart we find an average wind of 245° ==>(240+235+245+255)/4 this chart for flight level 180 they ask average wind at fl160 thus wind will be less than 245° (northern hemisphere) we find a wind speed of 46 25 kt wind force will also be less only one answer remains correct 240/40 . Question 127-13
Select from map average wind the route zurich hamburg at fl 240 305 When gusts are at least knots above mean wind speed. on left of zurich we notice a wind of 200°/20 kt on right of zurich wind from 250°/25 kt the average wind will be 230°/20 kt. Question 127-14
Select from map average wind the route shannon lisboa at fl 290 306 When gusts are at least knots above mean wind speed. the wind comes clearly from north at a speed of (70 + 90 + 90 + 85 + 80)/5 = 83 kt the map for fl300 speed at fl290 will be slower than 83 kt. Question 127-15
When otherwise calm and clear conditions exist a station on shore of a large body of water will experience wind From water in daytime from land at night. land breeze during night (land cold sea warm) during day situation reverses the wind will blow from sea (sea breeze) . Question 127-16
The greater pressure gradient Closer isobars the stronger wind. land breeze during night (land cold sea warm) during day situation reverses the wind will blow from sea (sea breeze) . Question 127-17
When isobars an area in mid latitudes on a weather map are close together wind most likely to be Closer isobars the stronger wind. land breeze during night (land cold sea warm) during day situation reverses the wind will blow from sea (sea breeze) . Question 127-18
In northern hemisphere a pilot flying at 1000 ft above ground level directly towards centre of a low pressure area will find wind blowing from Closer isobars the stronger wind. in northern hemisphere wind flows counter clockwise around a low the wind blowing from left behind. Question 127-19
In northern hemisphere wind at surface blows Counter clockwise around toward centre of a low pressure area. in northern hemisphere wind counter clockwise around low pressure the effect of surface friction will make wind 'back slack' in northern hemisphere. Question 127-20
Wind caused Horizontal pressure differences. in northern hemisphere wind counter clockwise around low pressure the effect of surface friction will make wind 'back slack' in northern hemisphere. Question 127-21
During a descent from 2000 ft above surface to surface no frontal passage northern hemisphere wind normally Horizontal pressure differences. at low elevations friction will slow air hence coriolis force will be less effective in its deflection of wind when entering in friction layer (at about 2000 ft above surface) as elevation decreases direction backs (changes direction in an counter clockwise motion) in northern hemisphere at mid latitude over land wind speed in friction layer decrease 50% angle between wind direction isobars changes 30° (value to be used in examinations). Question 127-22
The foehn wind a Horizontal pressure differences. katabatic wind (from greek katabaino to go down) the generic term downslope winds flowing from high elevations of mountains plateaus hills down their slopes to valleys or planes below katabatic winds exist in many parts of world there are many different names katabatic winds depending where they are located how they are formed warm dry katabatic winds occur on lee side of a mountain range situated in path of a depression examples these descending adiabatically warmed katabatic winds are foehn winds. Question 127-23
The sea breeze a wind from sea Occurring only in lower layers of atmosphere in daytime. katabatic wind (from greek katabaino to go down) the generic term downslope winds flowing from high elevations of mountains plateaus hills down their slopes to valleys or planes below katabatic winds exist in many parts of world there are many different names katabatic winds depending where they are located how they are formed warm dry katabatic winds occur on lee side of a mountain range situated in path of a depression examples these descending adiabatically warmed katabatic winds are foehn winds. Question 127-24
Geostrophic wind the wind when isobars are Straight lines no friction involved. we have a geostrophic wind when pressure gradient force (pgf) exactly balanced coriolis force it only happens when isobars are straights parallels if isobars are curved an additional force centrifugal force introduced always tries to throw parcel of air outwards from centre of its rotation the resulting movement of air called gradient wind with an area of high pressure (anticyclone) centrifugal force acting in same direction as pgf effectively increasing it coriolis balances total force (pgf + centrifugal force) the gradient wind 'high round a high' (i e a given gap between isobars gradient wind stronger than geostrophic wind) with an area of low pressure (cyclonic system) centrifugal force opposing pgf effectively decreasing it coriolis balances total force (pgf centrifugal force) the gradient wind 'low round a low' (i e a given gap between isobars gradient wind weaker than geostrophic wind). Question 127-25
What relationship exists between wind at 3000 feet and surface wind The wind at 3 feet parallel to isohypses the surface wind direction across isobars toward low pressure the surface wind weaker. we have a geostrophic wind when pressure gradient force (pgf) exactly balanced coriolis force it only happens when isobars are straights parallels if isobars are curved an additional force centrifugal force introduced always tries to throw parcel of air outwards from centre of its rotation the resulting movement of air called gradient wind with an area of high pressure (anticyclone) centrifugal force acting in same direction as pgf effectively increasing it coriolis balances total force (pgf + centrifugal force) the gradient wind 'high round a high' (i e a given gap between isobars gradient wind stronger than geostrophic wind) with an area of low pressure (cyclonic system) centrifugal force opposing pgf effectively decreasing it coriolis balances total force (pgf centrifugal force) the gradient wind 'low round a low' (i e a given gap between isobars gradient wind weaker than geostrophic wind). Question 127-26
The wind tends to follow contour lines isohypses above friction layer because The coriolis force tends to balance with horizontal pressure gradient force. we have a geostrophic wind when pressure gradient force (pgf) exactly balanced coriolis force it only happens when isobars are straights parallels if isobars are curved an additional force centrifugal force introduced always tries to throw parcel of air outwards from centre of its rotation the resulting movement of air called gradient wind with an area of high pressure (anticyclone) centrifugal force acting in same direction as pgf effectively increasing it coriolis balances total force (pgf + centrifugal force) the gradient wind 'high round a high' (i e a given gap between isobars gradient wind stronger than geostrophic wind) with an area of low pressure (cyclonic system) centrifugal force opposing pgf effectively decreasing it coriolis balances total force (pgf centrifugal force) the gradient wind 'low round a low' (i e a given gap between isobars gradient wind weaker than geostrophic wind). Question 127-27
The wind speed in a system with curved isobars compared to a system with straight isobars other conditions remain same Higher if curvature anticyclonic. we have a geostrophic wind when pressure gradient force (pgf) exactly balanced coriolis force it only happens when isobars are straights parallels if isobars are curved an additional force centrifugal force introduced always tries to throw parcel of air outwards from centre of its rotation the resulting movement of air called gradient wind with an area of high pressure (anticyclone) centrifugal force acting in same direction as pgf effectively increasing it coriolis balances total force (pgf + centrifugal force) the gradient wind 'high round a high' (i e a given gap between isobars gradient wind stronger than geostrophic wind) with an area of low pressure (cyclonic system) centrifugal force opposing pgf effectively decreasing it coriolis balances total force (pgf centrifugal force) the gradient wind 'low round a low' (i e a given gap between isobars gradient wind weaker than geostrophic wind). Question 127-28
The geostrophic wind depends on Density earth's rotation geographic latitude. to have a geostrophic wind we need to have a pressure gradient force (create density) coriolis force (create earth's rotation depending on geographic latitude) why density? we need to have two differents air mass to have a pressure gradient force (pgf) why earth's rotation geographic latitude? since earth rotates objects that are above earth apparently move or are deflected if they are already moving owing to it's rotation this apparent motion caused the coriolis force in northern hemisphere objects will be deflected to their right while in southern hemisphere objects will be deflected to their left the magnitude of deflection also a function of distance from equator velocity so farther from equator object is greater deflection the faster an object moving greater deflection these 'object can be anything from airplanes to birds to missiles to parcels of air the effect of coriolis force various latitudes . Question 127-29
In a mountain valley wind circulation mountain wind blows At night down from mountains. during day sun heats up valley air rapidly this causes it to rise causing a warm upslope wind (valley breeze) at night process reversed mountain air cools rapidly at night 'fall downslope causing a wind going in valley (mountain breeze) a mountain breeze a valley breeze are two related localized winds that occur one after other on a daily cycle. Question 127-30
Ahead of a warm front in northern hemisphere wind direction changes from surface up to tropopause the effect of this change that wind Veers in friction layer veers above friction layer. ahead of a warm front in northern hemisphere as ahead of a cold front wind veers in friction layer veers above friction layer we know that wind turns counterclockwise around a low pressure but an observer on ground looking at front wind veers (turn clockwise) at his position. Question 127-31
The difference between geostrophic wind and gradient wind caused Curvature of isobars. we have a geostrophic wind when pressure gradient force (pgf) exactly balanced coriolis force it only happens when isobars are straights parallels if isobars are curved an additional force centrifugal force introduced always tries to throw parcel of air outwards from centre of its rotation the resulting movement of air called gradient wind with an area of high pressure (anticyclone) centrifugal force acting in same direction as pgf effectively increasing it coriolis balances total force (pgf + centrifugal force) the gradient wind 'high round a high' (i e a given gap between isobars gradient wind stronger than geostrophic wind) with an area of low pressure (cyclonic system) centrifugal force opposing pgf effectively decreasing it coriolis balances total force (pgf centrifugal force) the gradient wind 'low round a low' (i e a given gap between isobars gradient wind weaker than geostrophic wind). Question 127-32
During periods of prolonged clear skies associated with anticyclonic conditions Surface wind speed tends to be highest during early afternoon. anticyclonic conditions indicate a high pressure system present with a high pressure system clear skies present we expect higher temperatures these are at their highest during afternoon as temperature near surface increases air density decreases so effect of surface friction lessened wind speed allowed to pick up. Question 127-33
The geostrophic wind speed directly proportional to Horizontal pressure gradient. the speed of a geostrophic wind calculated from pressure gradient air density rotational velocity of earth latitude the calculation ignores curvature of wins path a geostrophic wind proportional to pressure gradient or inversely proportional to distance between isobars winds exist because of horizontal vertical pressure gradient so atmospheric motion can be deduced from isobaric surface charts etc if horizontal pressure gradient force exactly balanced in magnitude coriolis effect accelerations of air will be relatively small a geostrophic wind will flow horizontally at a constant speed proportional to isobaric spacing gradient perpendicular to two opposing forces parallel to straight isobars thus geostrophic wind speed proportional to pressure gradient the closer isobars higher will be geostrophic wind speed. Question 127-34
A strong dry and warm downslope wind produced prior enforced ascent of air over hills or mountains known as a Horizontal pressure gradient. the speed of a geostrophic wind calculated from pressure gradient air density rotational velocity of earth latitude the calculation ignores curvature of wins path a geostrophic wind proportional to pressure gradient or inversely proportional to distance between isobars winds exist because of horizontal vertical pressure gradient so atmospheric motion can be deduced from isobaric surface charts etc if horizontal pressure gradient force exactly balanced in magnitude coriolis effect accelerations of air will be relatively small a geostrophic wind will flow horizontally at a constant speed proportional to isobaric spacing gradient perpendicular to two opposing forces parallel to straight isobars thus geostrophic wind speed proportional to pressure gradient the closer isobars higher will be geostrophic wind speed. Question 127-35
Geostrophic wind Is perpendicular to horizontal pressure gradient force. we have a geostrophic wind when pressure gradient force (pgf) exactly balanced coriolis force it only happens when isobars are straights parallels the (geostrophic) wind (yellow arrow) perpendicular to horizontal pressure gradient force (pgf) to coriolis force. Question 127-36
Which of following statements concerning jet streams correct In northern hemisphere both westerly easterly jet streams occur. in northern hemisphere both westerly easterly jet streams occur the tropical easterly jet stream blows only during summer from south east asia extending over southern india to central africa. Question 127-37
Under which of following conditions the most severe cat likely to be experienced A curved jet stream near a deep trough. a curving jet stream associated with a deep low pressure trough can be expected to cause great turbulence. Question 127-38
Above and below a low level inversion wind likely to Change significantly in speed direction. a low level inversion means that a temperature inversion forms near surface the airstream flowing over ground or water produces a turbulent layer (the friction layer) up to 500 feet deep in light winds or 3000 feet plus in strong winds the wind above inversion often increases because it insulated from frictional influence of surface above below a low level inversion wind likely to change significantly in speed direction. Question 127-39
Which of following statements concerning core of a polar front jet stream correct It lies at a height where there no horizontal temperature gradient slope of pressure surfaces at height of core at its maximum. the polar front jet core in warm air but above cold air tropopause at a point where temperature in warm air troposphere the same as cold air stratosphere if cold tropopause 40°c then above that point in cold sector temperature constant in warm air at same level as cold tropopause temperature will be warmer say 34°c but will decrease with altitude at point where temperature in warm air the same as 40°c in cold air stratosphere you will find strongest wind speed. Question 127-40
On a particular day part of a polar front jet stream runs from north to south in northern hemisphere this means that The polar air below to east of core of jet. normaly polar front jet stream runs from west to east it will be found in warm air of ferrel cell (sub tropical air mass) now let's assume direction north to south polar front jet remains in warm air above cold air the polar air remains below to east of core of jet.
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