[Dave K]

 or Part 2 of how to find things to do with yourself when you've taken a year off work and you're waiting for paint to dry and grouting to set  :D  

Though the temperature challenge isn't really finished, I'd like to do the same thing for rainfall but rather than extremes this time using at least 30 year averages to find highest/lowest average annual rainfall, maybe to give some different places a shot at  glory - surley somewhere like Seathwaite can help the UK nail down a podium place in this one?   ;)

This could take a while as I find out the more obscure places to look, especially in the tropics and I'm awating to complete my collection of climate data tables. Suggestions (pertinent to the quest) as before are welcome :-)

[Rupert Wood]

To get you off to a start, a high-rainfall station you won't find notes for on the Internet (unless you go to my website) is  "Waterfall" on the Cropp River, in South Westland, NZ. Mean rainfall 1982-2008 was 11,460mm (and 2009 was wetter than that, don't have a confirmed value yet). Could well be the wettest station outside the tropics, or at least beyond 30deg latitudes.

[Dave K]

Quote

Rupert Wood - 5/8/2010 20:39 To get you off to a start, a high-rainfall station you won't find notes for on the Internet (unless you go to my website) is  "Waterfall" on the Cropp River, in South Westland, NZ. Mean rainfall 1982-2008 was 11,460mm (and 2009 was wetter than that, don't have a confirmed value yet). Could well be the wettest station outside the tropics, or at least beyond 30deg latitudes.

Thanks Rupert, that is almost as much as the well reknowned high rainfall stations in Assam :o

Do you have a latitude and elevation for "Waterfall", not that I'm making any altitude dependencies - just not sure if I could find it in an atlas.

[Dave K]

I shall create proper tables for these again in due course, thought I'd start with Antarctic Circle to the South Pole and it would be easy...not so, again few of the bases seem to record precip and even fewer publish figures online. I guess with almost all Antarctic precip being snowfall it's very difficult anyway.

---

Antarctic Circle to South Pole. Average annual precipitation

Lowest: 2.0 mm, Scott-Amundsen Base, South Pole, Antarctica

Highest: 316.0 mm, Stonington Island, West Graham Land, Antarctica. *


* N.B. Data modelling suggests precipitation of 800 - 1 000 mm per annum due to orographic forcing over coastal escarpments in East and West Antarctica and the Antarctic Peninsular. Unable to find any recording stations though.

---

[Dave K]

Big thanks due to www.met.no for making a vast amount of station data available online and http://www.ncdc.noaa.gov/oa/ncdc.html of the USA and www.weatheroffice.gc.ca . Also managed to check Sweden, Finland, Greenland and Russia reasonably well.  The precipitation figures include rainfall and snowfall, with many figures being very surprisingly low for both. The high amount in Norway is of course due mainly to orographic forcing.

---

Arctic Circle to North Pole: Average Annual Precipitation

Lowest:  75.5 mm, Eureka, Ellesmere Island, Nunavut, Canada. 85.9°N

Highest: 2 525 mm, Kvitfossen i Vågan, Lofoten, Norway. 68.3°N, c. 700 masl

---

[Dave K]

Scotland doesn't even get near to the wettest place in the 55N - Arctic Circle latitude. Not exactly sure where the wettest place in the far NW of Scotland is ( Glen Etive? ) though the figure is less than 4 700mm according to Met Office graphs. I have to take on trust that the Oymyakon total includes snowfall as it is only just lower than the next lowest in Alaska (Tok, 218.4 mm)  for which the figures do explicitly include snowfall.

---

55°N to Arctic Circle: Average Annual Precipitation

Lowest:  215.0 mm, Oymyakon, Siberia, Russia. 63.5°N, 741 masl

Highest: 5 729 mm, Little Port Walter, Alaska, USA. 56.4°N, 3 masl

---

[Rupert Wood]

Quote

Big Dave's Gusset - 6/8/2010 20:34

Quote

Rupert Wood - 5/8/2010 20:39 To get you off to a start, a high-rainfall station you won't find notes for on the Internet (unless you go to my website) is  "Waterfall" on the Cropp River, in South Westland, NZ. Mean rainfall 1982-2008 was 11,460mm (and 2009 was wetter than that, don't have a confirmed value yet). Could well be the wettest station outside the tropics, or at least beyond 30deg latitudes.

Thanks Rupert, that is almost as much as the well reknowned high rainfall stations in Assam :o

Do you have a latitude and elevation for "Waterfall", not that I'm making any altitude dependencies - just not sure if I could find it in an atlas.

Altitude 975m ASL (there's another station a bit further downriver at 860m ASL, it is a little drier at about 10,500mm per annum) - latitude 43deg 5min S.

[Dave K]

Quote

Rupert Wood - 7/8/2010 03:44

Quote

Big Dave's Gusset - 6/8/2010 20:34

Quote

Rupert Wood - 5/8/2010 20:39 To get you off to a start, a high-rainfall station you won't find notes for on the Internet (unless you go to my website) is  "Waterfall" on the Cropp River, in South Westland, NZ. Mean rainfall 1982-2008 was 11,460mm (and 2009 was wetter than that, don't have a confirmed value yet). Could well be the wettest station outside the tropics, or at least beyond 30deg latitudes.

Thanks Rupert, that is almost as much as the well reknowned high rainfall stations in Assam :o

Do you have a latitude and elevation for "Waterfall", not that I'm making any altitude dependencies - just not sure if I could find it in an atlas.

Altitude 975m ASL (there's another station a bit further downriver at 860m ASL, it is a little drier at about 10,500mm per annum) - latitude 43deg 5min S.

Thanks again, I found the yearly and 365 day records for Cropp River on the NIWA site, I had no idea anywhere was as wet as that in NZ - certainly learn things with these "challenges".

[Rupert Wood]

It's interesting Dave that there may be spots upwind of Mt Cook/Aoraki, at similar altitudes to Cropp, with rainfalls of the order of 13,000 - 16,000 mm - but that remains as conjecture.

[Dave K]

The Antarctic/Sub-Antarctic again quite difficult to get information though I have turned up a couple of reasonable sources. Can't really be sure if the two I've selected really are highest and lowest, for example, South Georgia & South Sandwich Islands supposedly has 1 500mm per year but they straddle the 54/55°S line and there is no info as to exactly where the 1 500mm comes from - if it's South Sandwich Islands group then it's below 55°S for sure. Finding out about places I had no idea existed :-)

---

55°S to Antarctic Circle. Average annual precipitation

Lowest.: 224.9 mm, Casey Base (Australia), Antarctica. 66.5°S, 40 masl.

Highest: 1 368 mm, Islas Diego Ramirez, Southern Ocean, Chile Antarctic Region. 56.5 °S, <200 masl

---

[Dave K]

I thought that Crib Goch at 4 473 mm average might be in with a shot in the 45 - 55°N band but not a chance! Poor old UK, even our rainfall can't make the top ranking.

---

45° - 55°N : Average annual precipitation

Lowest.: 163 mm, Astrakhan, Russia. 46.4°N, 20 masl

Highest: 6 655 mm, Henderson Lake, Vancouver Island, British Columbia, Canada 49.1 °N, <200 masl

---

[Dave K]

Found a couple of new sources of info and have made some changes to the info on the previous posts, so here are the part completed tables for now:

[Dave K]

A couple of surprises in the 35 - 45° latitude bands, the first being a rather low maximum for the NH (have really tried to find somewhere wetter, e.g. USA, Japan); and that Death Valley (59.2 mm ) is not the driest place in its band, several places in the Xinkiang, China and especially the Takla Makan Desert and Turfan depression have lower averages, and all from 30 year 1971 - 2000 returns. Much contradictory information from Argentina with the same location varying by 40 - 50mm according to the source but the Pampas region does come in lower at least 30mm lower than the small area of Australia lower than 35 °S.

---

35° - 45° Northern Hemisphere: Average annual precipitation

Lowest.: 15.7  mm, Turpan, Xinjiang, China. 43.0 °N, 30m asl

Highest: 4 648 mm, Crkvica, Bosnia & Hercegovina. 43.9 °N, 1 410m asl

---

35° - 45° Southern Hemisphere: Average annual precipitation

Lowest.: 132.1  mm, Plaza Huincul, Neuquén, Argentina. 38.9 °S, 548m asl

Highest: 11 460.0 mm, "Waterfall", Cropp River, Westland NP, South Island, New Zealand. 43.1 °S, 975m asl 

---

[Rupert Wood]

It occurs to me that parts of NZ's Fiordland (nearly all of it is below 45S) would easily exceed the 7330mm for the Chilean location, but I don't have any data to hand.

[Dave K]

Quote

Rupert Wood - 9/8/2010 01:50 It occurs to me that parts of NZ's Fiordland (nearly all of it is below 45S) would easily exceed the 7330mm for the Chilean location, but I don't have any data to hand.

Reliable information on rainfall is proving rather hard to come by, whether this is because there aren't pluviometers in the wettest places or just that they aren't published on the web I'm not sure. 25 - 35 °S is being very difficult...all the highest rainfall figures ( just over 2 500mm/year in NSW/Queensland, Australia ) are surprisingly low when compared to NZ or the equivalent NH zone.

[Dave K]

I shall post this one as it seems to be rather definite:

---

25° - 35° Northern Hemisphere: Average annual precipitation

Lowest.: 0.7 mm, Dakhla Oasis, Egypt. 25.5 °N, 111m asl

Highest: 11 873 mm, Mawsynram, Meghalaya, India. 25.3 °N, 1 431m asl

---

[Dave K]

Max rainfall for this zone seems remarkably low compared with others. Not really certain if the Australian figure is the highest but I have checked Queensland too and higher totals all around 17 - 18 °S. Also scoured; Chile, Argentina, Paraguay, Uruguay, Brazil, South Africa, southern tips of Mozambique & Madagascar as far as possible and nothing is higher unless there are oceanic islands I have missed. Any help is appreciated...

---

25° - 35° Southern Hemisphere: Average annual precipitation

Lowest.: 17.0 mm, Chamonate Aerodrome, Copiapó, Atacama Desert, Chile. 27.3 °N, 291m asl

Highest: 2 598 mm, Tallowwood Point, NSW, Australia. 30.6 °N, 46m asl

---

[leopard]

Dave, re the 25-35S rainfall figures, I suspect your Tallowwood Point figure of 2598mm is probably the highest (or pretty close to it) in Australia.  I agree it sounds low, but as far as I'm aware that's about as high as the annual rainfall gets in that part of the world.  The highest rainfall areas in Australia (as you've probably already established) are in north Qld and SW Tasmania, i.e. outside the 25-35S latitude band.  If I find anything higher I'll let you know.

 Not sure about the other countries (S Africa, Paraguay, etc) but I'm also surprised there isn't anything higher.  If I had to pick somewhere I'd probably say southern Brazil, but sounds like you've already checked that out...

 

 

[Dave K]

Leo, I think maybe this diagram of the prevailing winds and ocean currents explains why rainfall figures are not as high as might be expected in South America from 25 - 35°S




I have found 1 897mm/pa south of 25 °S and 2 645mm/pa just north of 25 °S so it is possible that the Tallowwood Point reading is exceeded somewhere in SE Brazil from Porto Alegre to Sao Paulo, just can't be sure that I can find all the recording stations.

{EDIT} found that the Serro do Mar hills have around 3 600mm/pa but it straddles north and south of the 25 °S line. Will have to try and find more info.

[Dave K]

Again some uncertainty over maximum rainfall figures for southern hemisphere, northern hemisphere figures better documented online.

---

15° - 25° Northern Hemisphere: Average annual precipitation

Lowest.:   1.8 mm, Aswan Dam, Egypt. 24.0 °N, 200m asl

Highest: 11 640, Mt. Waialeale, Kauai, Hawaii, USA. 22.1 °N, 1 569m asl

---

15° - 25° Southern Hemisphere: Average annual precipitation

Lowest.:   0.8 mm, Arica, Atacama Desert, Chile. 18.5 °S, 65m asl

Highest: 9 322 mm, Takamaka, La Réunion, Indian Ocean. 21.3 °S, 1219m asl 

---