Rain and storm for Cpt

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Chuckmyster said:
the dams have dropped 0.4% since last week but i suspect they will be filling up later from yesterdays rainfall
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A few days last week were 'vrek' hot, so that drop in levels doesn't surprise me too much!

Correction: The DWA dam levels have not yet been updated (I mixed up 23 and 30 Sep figures).

I think most of Sunday's rain was too far east to have a significant effect on the local catchments. The SAEON Dwarsberg (Jonkershoek) mountain station only recorded 20mm, and weeks of reduced soil moisture has already affected runoff. Dams along the Garden Route might show an improvement.
 
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Gordon_R said:
A few days last week were 'vrek' hot, so that drop in levels doesn't surprise me too much!

N.B. The DWA table shows different values for Theewaterskloof last week, so there may be a statistical adjustment going on. The majority of the other dam levels were unchanged, and Wemmershoek showed a small increase for the week.

I think most of Sunday's rain was too far east to have a significant effect on the local catchments. The SAEON Dwarsberg (Jonkershoek) mountain station only recorded 20mm, and weeks of reduced soil moisture has already affected runoff. Dams along the Garden Route might show an improvement.
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the rain there at the dam yesterday was hectic from 8am to 9am, it was very very heavy, when i left at 9:30am thinking it was all over i got hit hard again at the bridge all the way to back home, so that big catchment area has alot of water that is going to filter down to the dam today and tomorrow.
Just my hunch
 
Chuckmyster said:
the rain there at the dam yesterday was hectic from 8am to 9am, it was very very heavy, when i left at 9:30am thinking it was all over i got hit hard again at the bridge all the way to back home, so that big catchment area has alot of water that is going to filter down to the dam today and tomorrow.
Just my hunch
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agreed, CoCT weekly report has 40.3mm for 28th/5.3mm for 29th for TWK - was surprised there was not a decent uplift, but let us see what tomorrow brings :-)
 
@Gordon_R

How does one go about finding historic weather data ?
I remember trying to find historic temps for Cape Town for my kids school project a while ago, and none the weather forecast sites let you go back in time.
 
scud said:
@Gordon_R

How does one go about finding historic weather data ?
I remember trying to find historic temps for Cape Town for my kids school project a while ago, and none the weather forecast sites let you go back in time.
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The SAWS has become very protective of historical weather data, and actually charges for access. There are a few international websites that offer the same data for free, but I can't think of the names.

The simplest place to start is Wikipedia, which has very basic records for every place on earth. It has links to the data sources, which were archived, but are no longer available: https://en.wikipedia.org/wiki/Cape_Town#Climate
 
Gordon_R said:
The SAWS has become very protective of historical weather data, and actually charges for access. There are a few international websites that offer the same data for free, but I can't think of the names.

The simplest place to start is Wikipedia, which has very basic records for every place on earth. It has links to the data sources, which were archived, but are no longer available: https://en.wikipedia.org/wiki/Cape_Town#Climate
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Thanks Gordon
It occurred to me that with accurate historic data you could then work out which forecast systems are the most accurate, would be an interesting project
 
T
Gordon_R said:
The SAWS has become very protective of historical weather data, and actually charges for access. There are a few international websites that offer the same data for free, but I can't think of the names.

The simplest place to start is Wikipedia, which has very basic records for every place on earth. It has links to the data sources, which were archived, but are no longer available: https://en.wikipedia.org/wiki/Cape_Town#Climate
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There are a few reasons for this SAWS attitude. One is all about funding. Where SAWS is expected to make money out of their data, which we as tax payers paid for already.
The other is and it has already been shown to be true in other places in the World, that the historical temperature data does not support the ACC agenda, and hence the data is deliberately being embargoed.
 
scud said:
Thanks Gordon
It occurred to me that with accurate historic data you could then work out which forecast systems are the most accurate, would be an interesting project
Click to expand...

All weather forecast models already include these prediction/feedback processes to improve quality. There is no single 'right' answer for any forecast, since they all operate on different scales, and with different weather events. There is some degree of 'feel' in interpreting the results, but this is a bit like watching horse racing...

The data that most interest the public are surface winds, rain and temperature, etc. These are only a tiny fraction of the model parameters, which operate at a global scale, and involve many layers of the atmosphere. By definition, aviation forecasts select a different subset of the model outputs.

Accuracy can improved the throwing more computer hardware at the problem, but ultimately the system is limited by the input data. This has to be laboriously gathered from surface readings, or interpolated from satellite observations. Diminishing returns result in incremental cost benefits.
 
Gordon_R said:
All weather forecast models already include these prediction/feedback processes to improve quality. There is no single 'right' answer for any forecast, since they all operate on different scales, and with different weather events. There is some degree of 'feel' in interpreting the results, but this is a bit like watching horse racing...

The data that most interest the public are surface winds, rain and temperature, etc. These are only a tiny fraction of the model parameters, which operate at a global scale, and involve many layers of the atmosphere. By definition, aviation forecasts select a different subset of the model outputs.

Accuracy can improved the throwing more computer hardware at the problem, but ultimately the system is limited by the input data. This has to be laboriously gathered from surface readings, or interpolated from satellite observations. Diminishing returns result in incremental cost benefits.
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Do you know if there is a home weather station that can upload / share local weather data with SAWS or similar ?
You can build them with a raspberry pi, but would be nice it the data got aggregated somewhere useful

this looks pretty interesting
 
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Yes it is possible for you to set up a weather station and then provide the data to SAWS, provided the station complies with their minimum spec and is installed according to their spec. If you were to do so, you will become an "insider" of sorts with privileges and access to data and info not in the public domain.
 
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