Cropp River sites

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RWood
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Cropp River sites

Unread post by RWood »

This may be of interest to Nev in particular, as I saw a posting on Weatherzone. The following, posted elsewhere some time ago, may clarify things a little.

These are 2 locations in a network that is mapped at NIWA's EDENZ (part of the Water Resources Centre):

http://edenz.niwa.co.nz/

Work on this website is not complete, for good non-technical reasons. I obtained my data by the kind offices of a staff member after trying the download (the data is in hourly total format and in some cases can be retrieved for short timespans).

As can be seen, there are 2 Westland sites on the Cropp River, in the catchment inland from Hokitika/Ross. Cropp Waterfall (975m ASL) and Cropp Hut (860m ASL) are the 2 wettest in the entire network, though Tuku is not far behind and the older Colliers Creek and Rapid Creek also have very high averages.

Vital statistics: (Hut 1979-2007, Waterfall 1982-2007)

Annual means (sum of monthly means): 11499 (W) 10563 (H)

Highest annual: 16617 (W, 1998) 14347 (H, 1998)

Highest 12 months: 18383 (W, 11/97-10/98) 15961 (H, same period) [highest 365-day value is 18442]

Lowest annual: 7975 (W, 1992) 8199 (H, 2005)

Wettest month on average: December (1278 W, 1108 H)

Highest monthly value: 2927 at Waterfall, Dec 1995
2460 at Hut, Nov 1994 (incomplete for 12/95)

Lowest monthly value: 114 at Waterfall, Feb 2007
86 at Hut, Feb 2007.
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Richard
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Re: Cropp River sites

Unread post by Richard »

gees some amazing figures there RW, and thanks for that link
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Re: Cropp River sites

Unread post by NZ Thunderstorm Soc »

When ever there are significant rainfall totals for a wet place in New Zealand, that area always seems to Cropp up #-o :lol:

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Re: Cropp River sites

Unread post by southernthrash »

There are areas on the main divide that have been measured as receiving as much as 20,000 mm precipition/year. Although, a significant proportion of that falls as snow so is converted to SWE
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tgsnoopy
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Re: Cropp River sites

Unread post by tgsnoopy »

southernthrash wrote:There are areas on the main divide that have been measured as receiving as much as 20,000 mm precipition/year. Although, a significant proportion of that falls as snow so is converted to SWE
I'd put money on wind vibration causing the gauges to tip prematurely giving higher readings.
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Re: Cropp River sites

Unread post by melja »

Got told by a guide that 25-50m of snow falls at the neve for the fox and franz glaciers every year which is just amazing but this still is only around 5m of rain so to have 20m of rain falling with a good proportion of it snow i find very hard to believe.
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Re: Cropp River sites

Unread post by RWood »

I can recall hearing a couple of papers presented years ago by some Met/NIWA scientists who had looked at the rainfall issues. Scarcity of data is of course a problem. However a short record at a site near Milford, closer to the optimum distance from the general axis of the divide, suggested an annual average of perhaps 13,000mm and it was suggested that at some favourable locations on the West Coast flanks of the divide it might be as much as 16,000 - that number being considerably more speculative than the first one.
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Richard
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Re: Cropp River sites

Unread post by Richard »

melja wrote:Got told by a guide that 25-50m of snow falls at the neve for the fox and franz glaciers every year which is just amazing but this still is only around 5m of rain so to have 20m of rain falling with a good proportion of it snow i find very hard to believe.
I personally would believe that a greater amount of that precipitation that does fall between coast and main divide would fall within the mid elevated western slopes.If for example the cloud base is at 300m there's simply a far greater cloud depth so as to allow for such an extreme level of condensation at those lower levels compared to cloud depth by the time it reaches the tops.
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