Newsletter of 23 Jan
SUNDAY JANUARY 23, 2011
23 January 2011
The article was written on 24 December, and says for the top half of the North Island, the first heavy rains would come on 22 January, the drought-breaker for some.
"Dargaville: heavy rain 24 January, only 5 rain days until then
Whangarei: good weather until 22 January
Auckland, mostly fine from 25 December - 22 January, (just 2-3 rain days expected
Thames; mostly good until 22 January, best 11-21 January
Hamilton: .. rain 23 January..".
We sent this to many newspapers, radio, TV, weather blogs etc, at the time, but they wouldn’t print the predictions. If they did then people could have properly prepared themselves.
La and Nina should win the Most Boring Two Words of The Year award. They are being thrown around like confetti at a wedding when anything happens, as when we get heavy wet weather, floods, droughts, fine afternoons, hot days, cold ones, trees rustling, fish biting, dolphins appearing, more earthquakes, less earthquakes, and the reason the dog ate your homework. People have discovered an exotic Spanish word that feels good to say and makes them appear knowledgeable. We always want to know when something will end, when is it likely to change, so let’s see if we can get to the bottom of this one.
The La Nina situation is that cooler ocean currents plus their associated winds, due to their interfacing with the air immediately above the sea’s surface, flow westward along the equatorial band, displacing southwards the warmer air that is above the Australian continent. That warmer air causes evaporation which becomes rain. Therefore the stronger the La Nina, the more of this displacement and the greater the extent of the process. Cool air doesn’t of itself cause rain. Upper level cold bands (jet streams) cause the rain to condense and fall once it has formed, but cold air, which is heavier and has a downward direction and not an upward one, won’t get it up there in the first place.
When does this process change? This process will stop when the cool air stops proceeding westward, which will slow the southward displacement of warmer air. If you are in a bath and you send water up the other end, the level rises at that other end but then wants to come back again, to restabilise. So when the sealevel in the west builds to a around 62cms higher than in the east, then, like the sloshing in a bath, to achieve equilibrium the water will begin to flow eastwards. As the sea is joined to the air when water flows east then we will see the wind begin to flow east too(westerlies), this has been called (since 1982) El Nino, the new changed process takes over, and cooler air is allowed to rise up the eastern seabord of Australia to once again reach higher latitudes. The cooler air has less potential for evaporation and eventually a drought takes hold. Remember the cooler air could not rise northwards before, because too much warmer air was busy coming southwards.
This is the Southern Oscillation Index (SOI), once called the Humboldt Current, now called the El Nino/La Nina cycle. The La Nina component used to be called The Trade Winds, as I remember when I was in Standard 3. It was always called that, and surely still is (unless the planet after 4.5 billion years has majorly switched all its ocean currents in the last 50 years) the more usual situation, taking about 3-4-years of build-up, with El Nino requiring about 1-1.5 years to restabilise. These have much variation but long term, average out to that ratio. These Trade Winds reach a peak before they turn about, now they call that a strong La Nina. By changing names of well-known perhaps boring weather systems scientists have discovered to their glee that they can attract new rounds of research funding, because they can introduce old systems as new concepts that need urgently to be studied, and busily report on progress of these ‘new developments’ through the year, as they say there is a need to “keep an eye on the situation”.
The result is a huge field of mystery where all weather is now regarded as anomalous, bizarre, unexplained and runaway. A fine afternoon or loud dog barking is pinned to El or La something. In the years 1969-72 we changed from Fahrenheit to Centigrade. Much focus was on what the new figures would read as in the new scales. I can remember that 86F would now be 30C. It was news because at that time January and February (1970) was very warm. According to NIWA-held archives Hamilton and Te Aroha weather stations recorded average maximums of 30C in January and February of that year. Nobody thought anything of it – it used to be called “summer”. Nowadays a summer day of 25C is considered unusually warm. We get TV anchors saying wow, it has never been this warm before and everyone believes them like sheep. We have short memories.
The SOI is tied to the moon. How? If the earth was perpendicular in its orbital rotation then the moon would orbit exactly around our equator. But the earth is not perpendicular but on a 23deg tilt. As far as the moon is concerned the earth is upright, with the moon going around Earth’s middle. Therefore the tilt requires that the moon moves between hemispheres, crossing at the equator only once every 13.6 days, and this is entirely due to the tilt of the earth. It suggests that the moon was formed at a time before the tilting took place. The way the moon forever spends half the month in each hemisphere is called the lunar declination cycle. On Monday, 20 January the moon was at its northernmost point, called northern declination. Result: heaps of rain for Queensland, because QLD’s latitude was closer to the latitude of the moon. Every 4.5 years in the declination cycle there is a balancing in the ocean’s currents such that a reversal takes place in the circular rotation of the great oceans. What happens in the southern Pacific also happens simultaneously in the Indian Ocean and the Southern Atlantic Ocean, and reverse rotations occur in the Northern Pacific and Northern Atlantic. That is the SOI.
Full moon period is warmer in summer
The moon distributes the sun’s heat indirectly. At times of full moon the air tide (total height above horizon) is low during the day and rises in the evening to meet the rising and transiting moon. Therefore, without the body of air in the way, the sun’s increased heat on summer full moon days can come closer to ground, bringing warmer conditions and enabling the massive evaporation from the surface of the sea around the equator for cyclones to form (26-28C is required). That is why cyclones so often form around summer full moons. It is also why skies are clear at night around full moon days – the rising evening air drives away the colder heavier air from space that would condense out clouds, result: the full moon “eats” clouds, as the old mariners used to say.
In the southern hemisphere summer, full moon is always accompanied by northern declination, it is a law. It means the full moon will appear low in the southern hemisphere sky, and its arc of transit is low. In the northern hemisphere's summer, full moon is always accompanied by southern declination, but the the same law applies. It means their summer full moon will appear low in their northern hemisphere sky, and its arc of transit is also low. So whoever is having summer will see full moon low in their sky. The reverse is true in winter, and whoever is having winter will see their full moon nearly overhead, because for the southern hemisphere the winter full moon is in the southern latitudes, and for the northern hemisphere their winter full moon is in their hemisphere.
22 January 2011
Today and tomorrow are kingtides, the highest for the month and thrid highest for the year. Kingtides always come around perigees, which is when the moon comes closest to Earth every 27 days. Whatever, either full or new moon, is nearest to perigee, will be the timing of the kingtide. This year it will be full moons until June, after August it will be at new moon times. This is on an 8.85=yr cycles, such that it changes around every 4 years, so in 2015 kingtides will be on new moons for the first half of the year and full moons for the second half. Today’s perigee is the ninth closest that the moon comes for the year. Next month at around the same time it'll be the 5th closest, and March it'll be the closest. In fact in 19 March the moon will be the closest it has come to Earth since 2008 and won't be as close again until 2016.
The kingtide is not just in the land but also in land and air. Consequently this week's full moon and the perigee has caused all sorts of havoc around the world. We've had cyclones in the air, kingtides in the sea, and earthquakes from the kingtides in the land. We had a big group of whales stranded themselves in Wellington yesterday, which just demonstrates how many more earthquakes must have been happening out at sea probably in the deep Kermadec trenches and underwater canyons, where the whales and dolphins go to chase big schools of fish. The shakes under the sea floor send shock waves into the water and the trenches act as amplifiers with their sloping walls. The tide then floats the whales in to the nearest shore. Many are just knocked out and need to recover. They don't want to be pushed out to sea again by kind-hearted people. That's why many just float back in. Some come in to rescue their mates and get caught themselves. They are the fit and well ones, and they should be helped back to deeper waters, not the ones still in shock.
Tomorrow, Sunday, the moon crosses the equator heading south, and consequently it's now dragging cyclonic weather that's happening in the islands, down to where we are. Not a whole lot, but just enough to wake us up, fill some of those coastal rivers, and rough the sea up offshore. Last Monday the moon was right in the north, and that's why we didn't get much storm action - the moon had slowed right down to nothing which it always does on northern declination. That's why Brisbane received the brunt of the weather, because it was closer to the moon's latitude. The barometer is falling, that's good for fishing, and should bottom out Tuesday or Thursday, then start rising again, along with a clearing of the weather over NZ. Anybody who looked up yesterday morning would have seen some beautiful cirrus formations in the clouds, resmbling candy floss. Well that is the sign of a front or a depression approaching, and when you see that you can expect unsettled weather any time in the next 36 hours. I was driving to Matamata, and it covered the whole Waikato sky. When you see it again, it is a sign that the depression is departing, so keep a lookout for it around Tuesday.
It would be an idea to stay away from the mountains and where the rivers end up because there could be some overlarge tides for a couple of days, especially if you have kids on a mountain camping trip people want to take care of sudden river level changes. In the North Island the rough weather will probably hang around until midweek then clear. And I'm expecting some much warmer temperatures at the end of next week, but the end of February will bring the hottest for the year.
Because the moon is universal, so the tides are as well. There are local differences due to geography and shape of coastlines, but a kingtide is global. The highest tides in any month are common to every country. For instance if you were to get on a plane and fly to the other hemisphere on a kingtide day you would find they too were enjoying kingtides that day. Another thing that is not generally known is that where there are two tides per day, the higher one is usually in the morning around the end/beginning of the year, and in the afternoon or evening in the middle of the year. It means that down in the southern hemisphere, the highest tides of the day occur usually in morning in the summer time and in afternoon or evening in the wintertime. So if you fish by-the-tide, just before high or just before the next low on the Waitemata, better to go in the morning in summer. For the Manukau it’s 3 hours later, so it’s just after the high and the next low.
And so if there are storms that occur in the summer time, it's in the morning that we have to be alert to this, because it's during this period of peak tide that those storms can do the most damage. For example in Brisbane, where they have had the flooding, if the tide height didn’t get to a certain height in the morning tide then it certainly wasn’t going to on the afternoon tide. And so if there are storms that occur in the winter, it's in the early evening that we have to be alert to this. Being in the opposite hemisphere the reverse is the case in Southern California, in that the highest tides of the day occur in usually early morning in their winter time and in early evening or late afternoon in their summer time. And so if there are storms that occur in their winter, it's in the early morning that they have to be alert to this, because it's during this period of peak tide that those storms can do the most damage. And those are early in the morning often in the winter time.
After Sunday, earthquake risks should lessen for a few days. When we mention earthquake risks we are offering opinions about timing. It is part of the old astrology that set out cycles of sun and moon as a predictive tool, and almanacs were printed that served as calendars. We have an education system that shuns the moon because it is part of an older religion and culture, and so must by definition be evil! It is quite amazing to see and hear how anti some folks get, and they haven't even looked at astrology and the moon beyond reading their horoscopes in the Herald or whatever. The moon to them is just some weird white thing that appears every now and then. I think they imagine it just wanders aimlessly around like a lost child. If you start to question them on this then they have to agree that it is in a predetermined position, just like Earth is. It is exactly at that spot through the balancing of gravitational forces. Therefore it has a gravitational job, therefore pulls earth and everything ON earth, including land, water, air, us.
Weather extended range
16th-23rd: A trough of low pressure brings disturbed westerlies and the passage of frontal systems.
24th: Southwesterlies are followed by a ridge of high pressure over the South Island on 25th. Weather may be still too wet to dry hay in the Waikato, to allow clearing for re-growth for a summer grazing rotation.
26th: Change to westerlies.
27th: Change to southerlies.
28th-31st: Northwesterly change, interrupted by a brief southwesterly change on 30th. Heavy rain in the South Island West Coast may flood creeks and rivers and block roads.
Most likely rainfall times by region extended range
Northland to Hamilton incl BoP: 23rd-26th (heaviest 23rd)
Western, Central North Is: 23rd-26th (heaviest 23rd)
Gisborne/HB: 23rd-26th (heaviest 24th)
Lower North Is: 23rd-24th, 26th (heaviest 23rd)
Nelson and Marlborough: 23rd, 29th
Canterbury: 23rd, 29th
Inland Otago: 21st-25th, 28th-29th (heaviest 23rd, 29th)
Coastal Otago: 19th-29th (heaviest 23rd. 29th)
Southland: 16th-25th, 28th-29th (heaviest 21st, 23rd, 29th)
Buller/West Coast/Fiordland: 23rd, 25th-31st (heaviest 23rd. 29th)
Information for this newsletter is extracted from the 500-page Predict Weather for NZ Almanac 2011
which can both be ordered from