Met Question

[Delta Oscar Charlie]

Hi again folks, hope you are all well and enjoying 2010

Doing my met exam shortly and a question that seems to be causing some debate between myself, an instructor friend and the guy who I bought the practice exam from is this..

"A mature tropical cyclone is moving south, the area of worst weather and strongest winds is"?

A:South west quadrant
B:North west quadrant
C:South east quadrant
D:all quadrants equally

I say south west in this particular case as the met books all say that the strongest winds and worst weather is to be found in the front or forward left quadrant of the storm, so therefore if the storm were moving east over the coast of western australia would the front/forward left quadrant be in the south east?, and if it were moving west would it be in the north west?

Practice exam guy says south east, picture yourself in the driving seat of the cyclone, Therefore whatever quadrant is out in front of your left is correct.

Instructor friend says south west at all times as the books do not differ from one storm direction to the other!

Please help as its driving me mad:ugh:

[OZBUSDRIVER]

A mature tropical cyclone is moving south, the area of worst weather and strongest winds is

So the answer is the south east, the front left quadrant as you FACE in the direction of movment.

[training wheels]

I remember this question and the MET book has the answer. Ozbusdriver is correct .. answer is south east. Cyclone is heading south so forward left quadrant is the south east quadrant.

[Lodown]

This helps explain a little of the "why".

From NOAA:

http://hurricanes.noaa.gov/pdf/hurricanebook.pdf

Page 10.

The Right Side of the Storm
As a general rule of thumb, the hurricane's right
side (relative to the direction it is travelling) is
the most dangerous part of the storm because of
the additive effect of the hurricane wind speed and
speed of the larger atmospheric flow (the steering
winds). The increased winds on the right side
increase the storm surge. Tornadoes are also more
common here.
Looking at the figure above, pretend you are
standing behind the hurricane with your back to the
steering flow. In this case, the right side is the
eastern section of the hurricane. (If it were travelling
east to west, the right side would be the north
section.) The winds around the hurricane's eye are
moving in a counterclockwise fashion. At Point A,
the hurricane winds are nearly in line with the
steering wind, adding to the strength of the winds. For example, if the steering currents are 30 mph and the average
hurricane winds are 100 mph, the wind speed would be 130 mph at Point A. On the other hand, the winds at Point B
are moving opposite those of the steering wind and therefore slow to 70 mph (100 - 30 mph). Incidentally, National
Huricane Center forecasts take this effect into account in their official wind estimates.

I'd change "right" to "left" for southern hemisphere.

[eocvictim]

Typically speaking cyclones generally start by heading west, hence south west... then they turn. :hmm: South-east.

[Delta Oscar Charlie]

Ok so if its like you guys are saying then the front left quadrant is always going to be in a different compass quadrant if the storm is moving in different directions, yes? And always put yourself in the driving seat of the cyclone to decide this!

Thanks for the replys

[OZBUSDRIVER]

DOC...By George...I think he's got it!:ok:

[takeonme]

I'd like to meet your "instructor friend".

[Delta Oscar Charlie]

Takeonme no need for the " marks, he doesn't claim to be an encyclopedia on all things aviation related and only conveyed to me what it says in the books that he has and that I have..

Thanks to all who had something helpful to say, much appreciated

[AerocatS2A]

Well the books say "front left" don't they?

A good way to remember this is to visualise why this is the worst part of the storm. Picture a cyclone moving south at say 10 knots with cyclonic (clockwise in the southern hemisphere) winds at 150 knots. The left side of the cyclone, relative to its direction of travel, will have winds at 150 knots plus the 10 knots that the cyclone itself is doing, so 160 knot winds over the ground. The winds on the right side are doing 150 knots in the opposite direction, that is, against the direction the cyclone is traveling at, so those winds will be 140 knots over the ground (150 - 10).

If you think about it like this rather than just rote learning "front left" you'll be able to remember it even if you forget the details (hmmm, was it front left or front right) and you'll also be able to answer a northern hemisphere question correctly without having to learn anything else other than that weather systems turn in the opposite direction up there.

It's similar to the problem of retreating blade stall in helicopters.

[j3pipercub]

Ask the lads flying around Burketown and Normanton in the next couple of days, they'll be able to speak from experience...

[Delta Oscar Charlie]

Thanks aerocat, that is helpful as to why it happens to be that sector.. much appreciated. Now I just have to pass the exam..:)

[Counter-rotation]

Hallelujah!! Yet another quality, meaningful exam question... :hmm:

One of the most important lessons I ever learnt in met - which side of a mature TC to fly through, to minimise the risk to the aircraft!! :yuk:

CR.

[AerocatS2A]

I appreciate the sentiment Counter-rotation, but I think it's a more practoical question than many. TCs are large area systems and flying through part of one is a reasonable thing to do. Knowing where the worst of the weather is is a good thing.

[Counter-rotation]

Aerocat - I take your point.

The OP has provided the question in quotation marks too - and if it is a direct quote, it does not even specify the hemisphere... A technicality maybe but these sorts of exam questions annoy the hell out of me.

Repeat after me - "Which of the following is MOST correct?"!! :ugh:

:ok: CR. :ugh: