october weather in nz

[skytrekker '64]

hi ther
it is my first post :O
I am planing to start my ppl in nz,in october
is it a good time?
dont have to much choice-company rules-but dont like wait to long
regards

[helibee]

Great time of year , lots of frosts , and that leads to a great smooth day

fixed wing or rotor for your ppl
all the best
hb:)

[haughtney1]

The month of my Birth....early on, expect the odd sou'westerly following a cold front...but as you move into the mid month..it settles down with plenty of smooth flying conditions.

[skytrekker '64]

thanks hb
frost-hm,beter then heat wave,I think
fixed wing-but I have also gyroplane in my planes/near future :ooh:
from web infos tuaranga has both-must try
looking forward!

[mattyj]

You have got to be kidding..never plan anything in the spring in NZ. (like weddings and stuff outdoors) windy, rainy grey etc..sorry to burst your bubble but the best time for flying in NZ is now!

Unless youre in the far south..central otago where the weather is always nice!!

[On Guard]

Good luck, don't know about frosts in Oct, few and far between unless you are training in Otago.

Weather is always variable in NZ, you will be exposed to good and bad days but that is what builds experience. Your instructor will manage this and slowly push you further as your experience grows.

Very good for your skill level in the long term.

During PPL you won't be allowed to fly in weather too marginal anyway.

[SmokingHole]

English is a pretty common requirement these days. Might have to brush up on this a bit by the looks.

[ForkTailedDrKiller]

Is there ever a "good" time to fly in NZ?

Dr :cool:

[kiwi chick]

Yeah there certainly is FTDK - when I'm firmly planted on the ground :E

Can get very very windy here in October, but ya take the good with the bad :ok:

[empacher48]

Mmmmm October, great time for flying.... Equinox winds coming through, here in the MacKenzie Country its the only time we can go flying in our cars!!!

The only time of year were the wind on the ground here is 60knots gusting 80knots occasionally over 90knots!! (The highest strength of wind I've seen on the ground here is 97knots, and yes, your cars struggle to stay on the ground then!!)

[kiwi chick]

Haha, right on empacher48! I was trying to be diplomatic but you've hit the nail on the head - here at least, round wellies, lol!


SmokingHole:
English is a pretty common requirement these days. Might have to brush up on this a bit by the looks

:ooh: :ooh: :ooh:

[ForkTailedDrKiller]

"Is there ever a "good" time to fly in NZ?"

That said, I spent 4 years in Palmerston North and can't say I recall the weather being a serious impediment to training for any length of time.

Dr :cool:

[pilotdude09]

The best time for flying in NZ would be December/January when its not dark untill 10-11pm in the South!

October in the south should be stable though, usually starts to warm up (if you call it that) to 15's-20's and you will have your wet and miserable days which is great because you will get the experience.

Ive never flown in the rain, havent done 'heaps' of flying but i would love to fly when there are actually some clouds! :(

[empacher48]

In all seriousness, I know in an earlier post I mentioned the strong winds which come through during October. But In general New Zealand has an interesting climate and you can get long periods under an anticyclone with settled weather and light winds, followed by just as long periods of strong westerlies or sou-westerlies and front after front.

You'll figure out with flying VFR there are periods where you are flying everyday, and moving through your training very quickly, followed by periods where you won't do a thing but drink tea! But that is part and parcel of flying down here. Just don't get too discouraged by those days you can't fly, because there are other things in your training you can do, like exams and listening to the stories that pilots seem to love to tell... (You know the ones, where so and so was flying along one day and this happened, and everything is blown out of proportion).

[Oktas8]

October is a very good month to start training.

So are the months of November, September, December, August, January, July, February, June, March, April, May.

It's like the real estate market - if you need a house, the best time to buy one is ... right now.

[c100driver]

WEATHER SYSTEMS OF THE NEW ZEALAND AREA


While the weather systems of other regions of the world are largely controlled by the existence of semi-permanent anti‑cyclones and depressions, the Tasman Sea, New Zealand area lacks these features. Semi‑permanent highs are located in the South Indian Ocean and the S.E. Pacific Ocean but the belt of high pressure which appears on mean pressure maps of the intervening area is explained by the passage from west to east of migratory anti‑cyclones. These travelling highs are separated by troughs of low pressure which extend from the tropical trade wind belt in the north down to the region of strong westerly winds and depressions to the south of New Zealand. The centres of the migratory highs normally move in an easterly direction at about latitude 35 South, being further north during winter and further south during summer.

In the trough of low pressure between two consecutive anti‑cyclones we find a "meridional front", so named because it takes the form of an arc with a meridian as chord. This front probably originates as an occlusion from the Indian Ocean and the warm front characteristics, cirrus and altostratus cloud, are usually evident as far east as the New Zealand area. For practical purposes`, however, it behaves as a simple cold front. The orientation of this front is NW‑SE in middle latitudes and WNW‑ESE near the Tropic of Capricorn. In tropical areas the front becomes parallel to the wind flow, slows down and finally disappears.

Although the average period between successive meridional fronts is 5 to 7 days, there is no great regularity in their appearance. More over, the behaviour of any given front may be greatly modified by the formation of wave depression's. Neglecting in the meantime these complications, the simple scheme of anti‑cyclone, simple cold front, anticyclone etc. gives a succession of weather known as "normal progression". The sequence of weather expected in the New Zealand area with normal progression is as follows:

(a) Fair weather and light variable winds with the first anti‑cyclone.

(b) Freshening N‑NW winds in most western and southern districts with the advance of the trough. Orographical cloud forms over the west of the high country.

(c) As the front gets nearer the wind strengthens considerably often reaching gale force about Cook Strait and the orographic cloud thickens bringing rain and drizzle.

(d) The front moves over the country from the SW bringing a period of general rain and a change to fresh SW winds.

(e) The SW wind gradually decreases and instability showers become less frequent.

(f) A‑return to light variable winds and fair weather with the next anti‑cyclone.

Because New Zealand lies to the south of the mean latitude along which the centres of the highs move, the prevailing wind is westerly in direction.

The simple sequence of normal progression outlined above is often upset by complications. The principal complications are

(a) The topography of New Zealand, i.e. the high mountain ranges.

(b) The formation of wave depressions on the meridional front.

THE EFFECT OF TOPOGRAPHY ON NORMAL PROGRESSION WEATHER

The effect of the high ranges of this country is to intensify the weather on the windward side and to shelter the lee side. The weather associated with a front passing over the ranges will be intensified on the windward side both by forced ascent and retardation of the advancing boundary surface. On the lee side the front will be less active.

As New Zealand is orientated SW‑NE the nature of the weather after the front passes is greatly affected by the direction of the wind behind the front. If the wind behind the front lies to the west of SW the wind will continue to blow onto the western coasts. The passage of the front on these coasts will be most clearly marked by a change in wind direction and a rise in pressure. The weather improvement will be gradual and partly cloudy skies with instability showers will cover the western regions. The eastern regions, being the sheltered side, will have only a temporary deterioration in the weather as the front passes.

Where the wind is orientated to the south of SW there will be an abrupt reversal of weather conditions with the passing of the front because the coastal region which was previously the sheltered coast is now the windward coast and vice versa. With the passage of the front weather in western districts immediately begins to improve, while the east coast bears the full force of the front as it moves over the country from the south. Weather conditions behind the front normally improve rapidly, and by the time the front reaches Hawkes Bay the conditions in Southland and Otago have improved. Western districts of the North Island and the Auckland Peninsula usually experience no more than a line of showers and a change in wind direction with the passage of the front.

THE EFFECT OF A WAVE DEPRESSION ON NORMAL PROGRESSION WEATHER

A wave depression may form on a cold .front and intensify the bad weather of that front. As a wave depression approaches New Zealand all areas exposed to the north and west are covered by stratiform cloud with scattered rain and poor visibility.

When the depression passes over the country, all areas within the central parts of the depression experience bad weather with strong winds, low ceilings and heavy rain. Eastern and southern districts being the exposed coastal areas may suffer southerly storms as the depression moves off the country.

AVIATION CLIMATOLOGY OF NEW ZEALAND

New Zealand has been divided into 9 main climatological areas for the purpose of this survey. The following are the areas concerned:

(i) North Auckland.

(ii) Central Districts of the North Island.

(iii) Bay of Plenty.

(iv) Hawkes Hay and Northern Wairarapa.

(v) Wanganui , Manawatu~ Wellington and Southern Wairarapa.

(vi) Nelson and Marlborough except the Kaikoura coast.

(vii) The West Coast of the South Island.

(viii) Canterbury and the Kaikoura Coast.

(ix) Otago and Southland.


NELSON AND MARLBOROUGH (EXCEPT KAIKOURA COAST)

This area is partially protected by mountains from all directions except north and this has a major influence on the weather. The Marlborough Sounds, being more exposed, have weather rather similar to Wellington.

The approach of a cold front has little effect on the weather of this area except when the wind direction ahead of the front has a northerly component when Marlborough may experience a strong north‑westerly wind. The passing of a cold front, with the wind behind the front coming from the south‑west, gives a brief deterioration in the weather with rain, followed by a rapid clearance.

If the wind behind the cold front is from a southerly direction the passage of the front over Marlborough is normally marked by only a brief period of rain. Nelson may not receive any rain from a front under these conditions, there being only a layer of middle and high cloud.

A depression passing through or near Cook Strait brings the worst weather. Under these conditions a strong north to north‑east wind blows onto the area bringing low cloud and heavy rain.

During the winter radiation fog forms in some of the valleys, but it is shallow and quickly dissipates in the early morning.

WEST COAST OF THE SOUTH ISLAND

This area is a narrow coastal strip with a high mountain range to the east which has a marked effect on the weather. Thus this area is exposed to' all weather from the west but sheltered from that which comes from the east. With the approach of a cold front the winds may become strong in the north and in the south, but the central area will continue to have moderate winds which will increase for only a short period before the arrival of the front. The cloud cover increases rapidly with the approach of the front, reinforced as it is by orographic cloud.

The front is retarded by the mountain ranges and its weather activity increases due to orographic lifting. Heavy precipitation accompanies the front giving the West Coast its well known wet climate.

If the wind behind the front is from the south‑west, showers will continue for sometime after the front has passed, but will gradually decrease with the approach of the following anti‑cyclone.

If the wind behind the front is orientated further to the south or south‑east there will be an abrupt reversal of conditions after the front has passed and the weather will clear almost immediately.

When a depression moves onto the South Island from the west the West Coast bears the full force of the storm, bringing strong winds and torrential rains. If the depression roves through Cook Strait or further north the area may receive strong north‑easterly winds but normally little rain falls. When a deep depression is centred to, the south of New Zealand the West Coast is swept by strong westerly winds which cause orographic cloud and rain to form over the ranges and extend over the coastal areas.

::.~? In anti‑cyclonic conditions, particularly on winter nights, a katabatic wind flows down the mountains o=n"~the coastal areas: JThese winds are often reinforced by an easterly airflow and the natural funnelling of the winds into the valleys.

CANTMDURY AND THE KAIKOURA COAST

This area is sheltered from the prevailing westerly winds by the Southern Alps, and the area enjoys a comparatively dry climate.

The approach of a weak to moderate cold front is barely perceptible with only a small increase in wind strength. If the front is vigorous with strong winds both before and after the front, Canterbury will be swept by a Fohn wind, known locally as a "Nortwester". If the following wind is south‑westerly, there is little change in the weather as the front passes, and after its passage the only visible change is a clearance in the middle cloud. If the wind behind the front is from the south or south‑east, the front moves up the coast from the south bringing an abrupt change in the weather. The front is accompanied by a line squall, with the wind changing rapidly from westerly to southerly. The front brings heavy rain which soon eases off as the front moves northward. Heavy showers are common in the cold southerly airstream, and they will persist until the wind decreases in strength or shifts back to a westerly direction.

When a depression is centered off the coast, the onshore southerly winds bring low cloud, heavy rain and poor visibility.

Fogs are common in Canterbury, particularly the coastal areas, and these fogs are of both the radiation and sea fog types. The fogs, being rapid forming and very persistent, constitute a serious hazard to flying.

OTAGO AND SOUTHLAND

This area can be subdivided into the following:

(i) Central Otago.

(ii) The Mountainous Regions.

(iii) The Coastal Plains.

CENTRAL OTAGO

This area is comparatively dry because it is surrounded by mountain ranges which shelter the area from the rain bearing winds. Fronts pass over Central Otago after depositing heavy rain on the ,coastal and mountainous regions. This area is subject to extremes of temperature, being very hot in summer and very cold in winter.

THE MOUNTAINOUS REGIONS

These regions particularly in the west have predominately on shore, cold moist winds. These circumstances, combined with the mountain ranges, favour the formation of orographic cloud which covers these regions most of the time bringing heavy rainfall. The weather during the passage of a front is intensified by the orographic effects.

THE COASTAL PLAINS

These plains particularly those to the south of the area are swept by cold, moist south‑westerly winds. The airmass, being unstable, carries with it many cumulus type clouds, which bring extensive showery periods. The passage of a cold front is marked by' heavy rain and squally conditions, which rapidly improve to showery conditions in the cold air following the front. Occasionally these areas may receive winds from the south‑east and under these conditions the south‑easterly coastal areas are covered by low orographic cloud.

MECHANICAL TURBULENCE IN NEW ZEALAND

New Zealand is essentially a mountainous country with many valleys and natural wind funnels favouring the formation of mechanical turbulence and gusty wind conditions.

In certain areas of New Zealand this turbulence combined with the gusty winds creates a flying hazard particularly for light aircraft. Due to the height of most of the mountain ranges this turbulence can be quite extensive, extending to many miles in the lee of the hills and often to many thousands of feet above the terrain. A further hazard is that much of this mechanical turbulence has a very large period in that the down‑draughts often extend over a wide area with compensating up‑draughts also extending over a wide area. This latter effect is very noticeable over the Kaikoura Ranges in N.W. wind conditions, when an aircraft may be caught in a down‑draught, the speed of which may often exceed the maximum rate of climb of the aircraft, so causing the aircraft to lose valuable altitude.

As New Zealand lies in a predominantly westerly airflow which is often strong and gusty it follows that most mechanical turbulence in New Zealand is associated with westerly winds.

Turbulence is most pronounced about valleys or breaks in the mountain ranges which funnel the wind, often in a different direction to the general wind flow. This funnelling increases the wind strength locally and when this airflow mixes with the general flow then turbulence will result. This turbulent mixing is very noticeable in the Cook Strait area.

The following areas are noted for their turbulence under certain wind conditions:

COOK STRAIT

In nearly all wind conditions the funnel effect of the Straits is very noticeable, the only real exception being winds from the north to north‑east. Often prior to the passage of a front the winds will be from a westerly quarter and will funnel through the Straits as a north‑west wind. If after the passage of a front the winds are from a southerly quarter they will funnel through the Straits as a south‑east wind. On other occasions the wind ‑nay continue to funnel through the Straits from the north‑west after the passage of a front. The reason for this change of direction in one case, and no change in the other is that the backbone ranges of New Zealand are orientated NE‑SW and the wind direction in the Straits area will depend on which side of this mountain backbone the wind flows.

The winds that are funnelled through the Straits usually undergo a change of direction and speed causing turbulent mixing. This turbulence often extends to some distance from the Straits both out to sea and over southern parts of the North Island. Southern Wairarapa indirectly also comes under the influence of this Cook Strait funnel under westerly wind conditions.

KAIKOURA RANGES

A westerly airstream moving onto the South Island of New Zealand is forced to rise in order to pass over the Southern Alps. That portion which crosses the Alps and then continues to cross over the Kaikoura Ranges will pass over very broken and high country.

During the passage of the airstream over this broken country it will be funnelled through valleys and retarded by mountain ranges causing large scale turbulence extending to a considerable height above the terrain.



SOUTHLAND

A large percentage of any airflow which blows towards a mountain range will be diverted around that range. In the Southland area there is a large increase in the wind strength due to this diversion of air around the south of the South Island ranges. The effect here i s very similar to that in the Cook Strait area where turbulent mixing of the general wind with the diverted airstream takes place. In areas such as the extreme south west of the South Island the rugged nature of the country adds to the turbulence.

THE CANTERBURY NOR tWESTEt

The Canterbury nortwester is a Fohn wind, which is defined as a warm, dry wind blowing down the lee side of a range of mountains.

A N.W. air stream blowing onto the South Island of New Zealand will be forced to rise in order to pass over the Southern Alps, although a percentage of this wind will be diverted through Cook Strait or to the south of New Zealand bringing strong winds to these areas.

The wind when rising to pasg over ~he Alps will cool adiabatically, initially at 5.4 F (3.0 C) per 1,000 feet until it reaches ;ts coNensation level and thence at approximately 2.7 F (1.5 C) per 1,000 feet. These winds having travelled a considerable distance over water are relatively moist and so very little cooling is necessary in order to reach their condensation level. As the air continues to rise orographic cloud forms and precipitation begins, and in the case of the Southern Alps which are comparatively high most of the moisture in the air will precipitate out bringing heavy rain to the West Coast.

When the wind spills down the leeward side of the Alps it wil; immediately begin to warm adiabatically, initially o at 2.7 F per 1,000 feet, but for most of the descent at 5.4 F per 1,000 feet as nearly all of the moisture has precipitated out of this air and fallen as rain in the Alps.

The difference in condensation levels on the western and eastern sides of the Alps is often considerable, and thus the temperature at any level on the eastern side will be higher than that on the western side. For example the condens­ation level on the western side of the Alps may be 2,000 feet and on the eastern side 8,000 feet, so the air temperature on the eastern side will be approximately 16 F warmer at the 2,000 feet level.

The wind as it spills down off the mountains begins to roll and becomes very turbulent and gusty.' Thus the wind now blows over Canterbury and adjacent areas as a hot, dry, turbulent and very strong wind making light aircraft operations hazardous and often restricting heavy aircraft. The main hazards are

(1) Strong to gale force winds.

(2) Extreme gustiness.

(3) Reduced visibility due to dust etc.

(4) Extreme turbulence often extending to high levels.

The onset of a nor'wester can often be forecast by the definite break in the higher cloud along the Southern Alps. This break is often referred to locally as the "North West Arch" and usually precedes the onset of the Fohn wind by a few hours.

The Fohn wind does not always reach to the ground and its existence at higher levels can often be detected by the formation of lenticular clouds at the crest of each "Standing Wave". These standing waves are formed by the wave motion of the air as it spills over the Southern Alps. When the N.W. wind does not reach to the ground Canterbury receives a N.E. wind which is part of the airflow through Cook Strait which has curved around to flow down past Kaikoura and so over Canterbury.

[skytrekker '64]

thanks everyone
I am in
regards


ps.smokinghole-"frankly,darling-I dont give a :mad:"

[Jack Sprat]

Have a look at www.predictweather.com. The author, Ken Ring, appears in the media regularly and does 12 month forecasts for NZ, AS and UK. Lots of other interesting stuff there as well.

[ForkTailedDrKiller]

"A brief look at NZ weather "

Brief?

Dr :cool:

[c100driver]

OK then,

Expect 4 seasons in one day!

[toolowtoofast]

Well today, we're sitting under a big anti-cyclone, here's the forecast:

Fine and cloudy periods. A few light showers, gradually becoming confined to western areas from Waitomo down to Manawatu.

so far, it started foggy, then was sunny, now it's 8/8ths, but should clear this afternoon. a few spots of rain may fall the way it's looking right now......

i shouldn't think october's much different.

[kiwi chick]

Haha, and here its:

Started cold, got warm, skies clear, now warmer, few bits of SC out the window, no wind. :)

and I'll be back in an hour with new, different weather :ok:

[skytrekker '64]

thanks again
here,in uk summer is over-was very,very wet
so,maybe Mother Nature will keep things in balance...:rolleyes:
and october/november in nz will be...great this year
we will see...:zzz:
soon...
regards