The Hot Weather

[PigDogg]

April is generally the hottest month. I thought that was due to monsoon patterns.

But I saw this:

The department earlier predicted that April 27 would be the hottest day of the year because the sun would be at its most direct point over Thailand.

I thought in the Northern Hemisphere the sun was most direct around June 20th?

[Snick]

I didn't understand that bit either.
April/May are the hottest months, and this is the hottest May I can remember.

[PigDogg]

Still don't understand but here's someone's comment:

the article states "The department earlier predicted that April 27 would be the hottest day of the year because the sun would be at its most direct point over Thailand."
But I think there are TWO days where the sun is most direct point over Bangkok.
Bangkok lies on latitude 13.5 North, the Sun travels upto The Tropic of Cancer that lies 23º 26′ 17″ north of the Equator.
So there must be another day, where the sun sits staight above Bangkok, which I guess will be somewhere 15thAugust.
But because this falls in the raining season the Temperature will not be that high on that day.

On Monday it was 43 degrees centigrade in Phrae, not sure what that maps to in Farenheit but imagine it's hot, hot, hot.

[Bumblebee]

Don't be complaining gents, frost here last night, and hailstones this morning. The merry month of May, I don't think so. Stop hogging all the heat over in Los, share it around, and some LBs also while you are at it.

[Steff]

The heat does not seem to be a problem especially when you get to bed at 05h00 and head out again at 18h00. The Allycat prowl is the best way to deal with the heat.

Today I was out by 15h00 and it was very pleasant. I went over to Soi 6 and was treated well by a team of medical nurses who recognized I had a condition that required attending to. Within a drink or two they identified the malady and proposed a remedy which they claimed could be applied upstairs for a reasonable fee. They convinced me of the medical urgency and I was admitted immediately. Sure enough my problem was dealt with professionally and within the hour I was relieved. However the two nurses in attendance cautioned me that the symptoms will undoubtedly occur again and when they do I should seek their help immediately. They even offered to make a house call.

As I write this I am feeling some discomfort again and will have to take a baht bus back to the Soi 6 medical facility...

[guydesavoy]

(PigDogg @ May 12 2010,17:38) On Monday it was 43 degrees centigrade in Phrae, not sure what that maps to in Farenheit but imagine it's hot, hot, hot.

That's around 113 farenheit....as you say hot hot hot...

But quite usual in the antipodes in summer  

[Jake_Sully]

Actually that is in some ways accurate although its not 100% Accurate.

The summer solstice for the northern hemisphere is June 20th but that happens to be for those at exactly 45 degrees latitude, hence the extra long days. I'm over in New York and on that day the sun rises at like 4:40 am and doesn't set till 8:40pm. The days in between the solstice varies by latitude shifting between the northern and southern latitudes daily by a bit and Thailand being in the tropics, I'd actually guess the 2 solstice points are somewhere in may and late july.

And humidity is always going to make it feel hotter than it is so I think the dates are a rough projection of the longest days in thailand but since its in the tropics, there'll be 2, not 1 since the solstice moves from the southern hemisphere to the northern and then back down again and thailand isn't at the extreme end of it.

[Tomcat]

(Bumblebee @ May 12 2010,18:45) Don't be complaining gents, frost here last night, and hailstones this morning.

It has been reported in many Science articles that the Gulf Stream may gave been ruptured due to a number of causes that i wont go into here but it maybe affecting the weather in Northern Europe thats for sure. The Gulf Stream is the only reason that the UK gets any heat period... and you guys in Eire ( sounds like you really in Greenland now)

As the world gets hotter on average , North Europe gets cooler...

Its not been widely reported in the press as the Europeans have enough bad news without being told that Summer is the new Winter.

[kahuna]

It was so hot in Pattaya yesterday, I saw two trees fighting over a dog...

[Ivor Biggun]

It has seemed to me this year to have been an even hotter May than usual. Even Thais I know are finding it oppressive at the moment. A big storm came through last night, blowing out a lot of electric in patong around 3am. It cleared the air for a bit but it's now humid again.Thai authorities issued a public health warning earlier this week after nationwide temperatures soared to their highest in 20 years.
http://www.phuketgazette.net/archive...ticle8690.html

[Jake_Sully]

We're having the coolest spring in the last 20 years.. The normal here is 20C yet temperatures are under 10C for the last 2 weeks and I had a cold and flu not due to spring pollen but due to the weather.

Global Warming?

[geezer]

Surely that Icelandic volcano would be having some effect on the european temperature as well. Don't mind it myself. I hate the heat.

[Road Runner]

(geezer @ May 13 2010,17:21) Surely that Icelandic volcano would be having some effect on the european temperature as well.

To borrow from British Rail - 'It's the wrong kind of volcano'

The one in Iceland is probably too small to have any noticable effect.
Plus different types of volcano throw up different types of particles.

The one most people will remember was Mount St. Helens in Washington State .
That threw up huge quantaties of pumice which is very light in weight and dark in colour.
The large dark clouds coverered a big area and travelled a long way.

'Detectable amounts of ash covered 22,000 square miles (57,000 km2)' Wikipedia


The one in Iceland is putting up small quantaties of something similar to glass.
Hard to see and it has little or no effect on the amount of sunlight that reaches the surface.


RR.

[Road Runner]

The department earlier predicted that April 27 would be the hottest day of the year because the sun would be at its most direct point over Thailand.

That must be the Department of They Don't Know What They Are Talking About!    



The (hopefully )  simple explanation.


I'm sure everyone here knows that the sun apparently moves into the northern hemisphere in the summer and the southern hemisphere in the winter.
As PigDogg (nearly   ) rightly stated it reaches it's furthest point north normally sometime on the 21st June,
though about one year out of 8 or 9 it does occur on the 20th June.
Similarly on about the 21st December the Sun reaches it furthest point south, though again it can be on the 20th Dec.
(The reason for the variation in dates is the same reason we have leap years  -  an astonomical year is 365.2425 days long)

Really what happens is the Earth spins on it's axis through the poles.
At the same time the ends of that axis is describing a circle  -  think of a gyroscope that is starting to lose speed and starts to wobble.
It's called precession  -  lovely word that.   (See the pretty picture at the bottom of this post!)



The Sun crosses the Equator (The Earth is in effect level in comparison to the SUN) on the 21st April spring or Vernal Equinox and the 21st September Autumnal Equinox.

The latitude of Bangkok is 13.75 degrees north of the equator.
On the 27th April 2010 the Sun was apparently on the same lattitude 13.75 degrees and so at astronomical noon the sun would be straight up above your head in Bangkok.
(Note that the time your clock shows can be anywhee from a few minutes to as much as 2 hours different to astronomical time  -  blame your government!)



So you would think that would be the hottest time of the year?

OK direct sunlight is VERY hot  -  we all know that.
But the heating effect of the sun on the Earth itself lags roughly 3/4 weeks behind the sun.
For us in the northern hemisphere the hotest days are in late July and the coldest in late January.
Funily enough no-one ever explained why that was when I did meterology!
I'm pretty sure it's connected with the heating effect of the sun on the water in the oceans and the way the energy is stored and released.

Simply put it's more likely to be hotter in late July anywhere in the northern hemisphere and similarly it's more likely to be hotter in late January in the southern hemisphere.

Though again as PD rightly pointed out the countries bordering the Indian Ocean are greatly affected by the monsoon which is a direct result of the heating effect of the sun on the ocean water.


RR.

[PigDogg]

Excellent explanation Roadrunner!!

Btw-According to Snopes, hemispherical variation of toilet flushing due to the Coriolis Force is an urban myth.