QUOTE(Shauna_15 @ Sep 4 2009, 11:53 PM)
I'm 15, and I live in Ontario, Canada.
I'll be writing my PPL exam in a little less than a month, and I was just wandering if there will be very specific questions such as the types of clouds needed to create a specific type of precipitation, or will it just ask general questions about things.
Any help would be appreciated,
Well, if they do ask about specific clouds for precipitation - try reading an ATPL book on the subject of MET - and you will find enough knowledge for you to answer any questions on the subject. they will not be looking for massive academic knowledge but the must know the difference between a fair weather (or small) Cu and a Cumulo-Nimbus cloud - one could kill you and the other may very well do so, unless you avoid it.
Try the following exercise at home:
There are two types of cloud form:-
Strato-Form and Cumulo form.
Stratoform is flate linear type of cloud and Cumuloform is bullbous fluffy cloud and is formed by uplift of converging air.
air converging against a mountain, air converging and rising due to heat from Insolation converging and uplifting due to airmasses converging. you know about convection, if not then read all about it and you know about condensation, if not - ditto -.
Strato form cloud can be gathered up by turbulence and become Stro-Cu. or ST Cu or SCu or SC or Sc.
Statos is St
StratoCu is Sc
Small Cu is Cu
Cumulonimbus is Cb
NimboStatus is NS
AltoCumoulus is AC
AltoStratos is AS
Cirrus is Ci
CirroCu is Cu
CirroStratos is Cs
Fog is FG
Mist is BR
Haze is HZ
AltoCumulous Castellanous is . . . .?
You must go to your text book and copy the cloud types onto your chart which you are no going to draw.
Cloud is described in three layers:-
Hi level cloud - Ci, Cc, Cs, As (plus tops of CB)
Med lecvel cloud is NS, large Cu, AC Castellanous, AC, Cb, As
Lo level cloud is St, Sc, Cb.
(Although Cb is a Med level or high level cloud it extends often down to 1,000 FT AGL or below and up to the tropopause when there is considerable uplift)
Hi LVL cloud is: 18,000 to 30,000 or higher
Med LVL is: 6,000 to 18,000
Lo LVL is: 200 to 6,000 feet. (ft)
NS even though a MED lvl cloud often has a base of 1,000 feet or lower - a g l.
Also - Alto stratos is thin veil like type of cloud that gives the moon a kind of halo effect.
You now have a list or two of clouds, keep these as you are going to need them in a minute.
If you know how to decipher a METAR and a TAF then you know the abbreviations of the precipitation like, Rain showers is RASH. If you don`t know the abbreviations yet, then postpone your exam until you do - that way you save money. If you don`t know how to decipher a METAR or TAF, then start on that right away - because you need to know what the weather is and also you need to pass the exam, therefore you need to decipher - a METAR and a TAF (and to know the difference between the two) one ias a report - metaR and the other is a forecast taF ok?
Now take a page out of your A4 note book and rotate it 90 deg so the width is greater than the height.
With a ruler and pencil draw a horizontal line across the middle of the page. draw a tiny cross a third of the way along the line from the left margin. Do the same again two thirds the way along the horizontal line again.
Using your ruler, draw a 45 deg angle slant line from the first cross, slanting left to off the page. [\ ]see?
Using your ruler, do the same for a 45 deg angle slant line to the right - from the right hand tiny cross to off the page [/] see?
Write C/F in little letters on the left slope - write W/F in little letters on the right slope. Cold Front. Warm Front.
Write 30,000 in the top left hand margin
Write SFC on the left in the margin on your horizontal line. draw a tiny tree and a tiny building on the horizontal line for perspective as it is the surface of the Earth (SFC).
From your list above draw the hi lvl clouds (from the pickys in your text book) onto the Warm Frontat the altitudes from your list above.
Keep all the cloud outlines you are drawing to the left of the W.F line but on it. write in the little abbreviations, like, AC. Exclude CB.
Do the same for the Med lvl clouds at the altitudes from your list. Exclude CB Exclude AC Castellanous but include AC
Be sure to draw the clouds to cover the altitude band they are in. be sure not to cross the W/F line, keep to the left but on the line.
Do the Same for the lo lvl cloud - Exclude CB.
Now go to the Cold Front (slant line)(on the left)
Same as before ONLY THIS TIME PUT ALL THE CLOUDS ON THE RIGHT OF THE C/F/ LINE but on the line.
Draw the Hi lvl cloud Exclude AS
Draw the Med lvl cloud Exclude AC Castellanous but include AC. Exclude NS.
Do the same for the Lo lvl cloud all from your lo lvl list.
On the W/F (to the right of your page) draw dots representing drizzle (DZ) between 2,000 and the SFC on the W/F but on the left of it. Draw Rain ahead of it from Med lvl to SFC
In the middle of the page between the fronts draw in AC Castellanous at the Correct alt. draw in ST and bit of SC at the correct levl here too. Mix em up. In this space too, (the warm sector) draw in HZ from the SFC to about 5,000ft. although Hz is not cloud, but dust particles in the atmosphere making visibility c--p. I have RTB more than once due to bad Hz and even in embarrasment and yet, I am still alive to tell the tale.
Hz although not often classed as IMC will unerringly, put you in IMC, whether you like it or not.
To the left of the C/F slope at the correct level draw in Cu, and some AC just behind the front about a few miles.
If you want a scale? Its 230 miles from the hi lvl W/F cloud to the SFC front of the W/F - OK?
Draw in HVY RAin a bit ahead of the C/F on the C/F and behind the C/F at the SFC from say 1,000 ft.
RA and SN hn and behind the C/F nerear the SFC and hail just below the anvil of an CBs.
Draw in Cs in bits behind the C/F at the correct alts from your list above and or at the same lvl of Cbs which have passed by on the C/F.
Now you have this little chart go to the text books and re-check out all the precipitations relating to the clouds and double check against your chart, because I am just generalising.
Memorize this chart, which is easy to do.
Then when you have this taped - look up what causes fog, what fog types there are.
The basic and paramount need here, is for you, a PPL pilot, to fly and remain in VFR/VMC.
In your text books you will find what clouds give what Precipitation. now you have the chart you can compare with the book.
Cb clouds give Heavy Rain sometines Snow and / or Hail.. Nimostratus gives Rain and sometimes SNow, and or Drizzle or ice pellets commonly mistaken as Hail.
Hail comes from the anvil of the Cbs. the Cbs have three stages of development which you need to know and you will find it in your books. For Cb cloud - AVOID LIKE THE PLAGUE.
Mix the clouds and conditions and you get a mixture of the precip - sleet for example.
Mix fronts when they occlude or the fronts become bent back or quasi-stationary and you will get a mix of the conditions - as also near a low you may find c--ppy weather.
Just behind the advancing W/F you will get Rain Ice or clear Ice, same thing. this will weigh down the aircraft, it is heavy and sticks tight - recovery is descend to the warmer air below (subject to MSA) or do a 180 into clearer air.
With high ground around you need to know your MSA - there are more dead pil;ots due to neglecting this little factor than there are paragraphs in this post.
All pilots are critically appreciative and constantly aware of their local MSA, or in the vicinty of their airfield, the SSA.
Departing Alicante Spain - desiring to track North Easterly - what would you consider to be a cool MSA?
Therefore, approaching Alicante from due North/North East in IMC at night - why would you feel - extra-alert?
What would your MSA be if you wanted to swan around the Andes mountains?
In precipitation you cannot see out, if this is the case you are in IMC and in this case you need the MSA.
At your level, in the aobve conditions, you simply would not be flying - hopefully.
At your stage in the game you need simply to keep away from IMC and precipitation.
Any quirks or non-logic anomolies - then do not hesitate to ask questions on here, or to anyone in your club.
Ask which are the best books to buy for the questions you want to ask - as everyone here learned all this stuff by reading until they were blue in the face, which they don`t mind because they love the subject so much.
When you get to do ATPL studies, in order to prepare you for flying through most weather as opposed to flying just in VMC/VFR then you have to study all this stuff to a more academic level and know what conditions of temperature give you what weather, what precipitation and what winds at what time of year at whatever location in the world, as well as climatology.
Also, hear this, there are two types of weather system, a low pressure system and a high one.
All wind converges into a low just as the flow of water converges down the plug-hole in the sink.
the low pressure might be caused by rising air due to insolation - which is when the sun heats the earth which heats the air above it which rises. . etc., etc.,
Hi press systems are like taking a bag of flour and tipping it onto your kitchen table into a pyramid. Now get the flat of your hand and bring it down smartly onto the stack of flour - see all the flour diverges outwards covering everything in the kitchen - this is basically what happens to the air in a high press system.
Lo press systems like the one you just drew on your chart - rotates anti-clokwise in the N.Hemisphere and High press systems rotate clockwise in the N.Hemisphere. If you stand with your back to the wind in the N.Hemis then the Low is on your left ---- and any Hi is on your right.
The above is good for identifying wind velocity.
What you have just drawn is a warm sector depression.
The gap between the two fronts is called the Warm Sector.
Here is a Link;http://www.auf.asn.au/meteorology/section3.html
Good Luck in the Exams.
Also - be advised that exceptionally Thunderstorms can occur at a warm front when warm air is unstable.