Rain and storm for Cpt

Gordon_R

Gordon_R

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ChrisJ said:
Skeleton gorge yesterday afternoon, streams still following well on the city and Newlands side this evening
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That's probably one of the shortest summer dry seasons in the last decade, from December to March. I can recall years that seemed to be dry from October through to April. And there was the 2017 drought year...
 
DWPTA

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Gordon_R said:
That's probably one of the shortest summer dry seasons in the last decade, from December to March. I can recall years that seemed to be dry from October through to April. And there was the 2017 drought year...
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Wel I think we can all agree on rather having a short dry summer than having another 2017 again, by which all accounts can happen again.
 
Gordon_R

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A cutoff-low is developing over the SW-Cape this evening. It is cold and grey with a fresh SE wind, but not much rain is expected for CT itself. The peak precipitation will be in the Overberg, and moving offshore tomorrow (Mon 15th).
 
Gordon_R

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Bucketing down at 2:30am in Kenilworth!

Edit: Storm is over now at 3:30am. Found 22mm in gauge here!

Combined with the 65mm we had on Wed 10th, this is the wettest week in March that I can ever recall in CT...
 
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cenredash

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Gordon_R said:
I forgot to check dam levels, which are highly satisfactory for this time of year. The average rose 1% to 75% on 15 March. See: https://www.capetown.gov.za/Family and home/residential-utility-services/residential-water-and-sanitation-services/this-weeks-dam-levels

The current levels are the highest they have been since 2015. See: https://resource.capetown.gov.za/documentcentre/Documents/City research reports and review/damlevels.pdf
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Thanks for the reminder @Gordon_R

I don't want to speak to soon, but I think we'll be okay this year (for avoiding water restrictions).

We usually turn the corner in May and at latest June, when the monthly usage and the amount of water inflow into the dams are about the same, so roughly 6-10 weeks.


Our daily usage, which i assume includes agriculture, is on average 1000 million litres per day. That's about 30 0000 million litres per month and with the dams at about 670 000 (and us not being able to use the last 10% or so, so minus 90, make that 100 000 million litres) we should be good for 19 months if no rain falls ever, at our current consumption.

When i speak to a year below I mean roughly from May/June one year to May June the next.
In 2018 at the height of water restrictions we had a swing of about 38% in the dams, so an increase for the full rainy season of nearly 40%. While in 2014 we had a fall of about 50% in the dam level. 50% over a year would probably equate to 450 000 million litres, and that, over a 360 day period, would be around 1200 million litres per day, on average.

With the end of the hydrological year at 31 October and to be at 80% to maintain current water restrictions,
  • and we have a dry-ish rest of March
  • with May and June holding their own (we use as much in the month as the dams fill, so about 30 000 million litres),
  • we need a net gain of almost 10% dam filling over usage for July to end October, or a net gain of 90 000 million litres,
  • or if we expect September and October to just be holding their own, we will need to be at 85% by end of August.
 
Gordon_R

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@cenredash I'm not even looking at the figures, just curious what the levels are. We have enough water to be comfortable for the next 18 months, which is what the dams are designed for.
 
Gordon_R

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WAslayer said:
Anybody else had a completely unexpected shower..?
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A weak cold front. Yesterday's north westerly wind and fog was a clue. Totally predicted, but not publicised because of the small amount of rain, and it is the middle of the night.

Edit: The sun was shining this morning. The main effect of cold fronts at this time of year is a significant drop in temperature. This will persist until Mon 22nd due to another weak front. It will be much warmer next week.
 
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Gordon_R

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SABC TV showed footage of rare March flowers in Namaqualand (Nieuwoudtville), following the recent widespread rains. Mostly Brunsvigia and Haemanthus.
 
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MirageF1

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Gordon_R said:
The main effect of cold fronts at this time of year is a significant drop in temperature. This will persist until Mon 22nd due to another weak front. It will be much warmer next week.
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My weather forecast claims 30+ for early next week but I don't think we've topped high 20s in last 2 weeks in spite of forecasts. That's why forecasts are forecasts and not facts.
 
Gordon_R

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MirageF1 said:
My weather forecast claims 30+ for early next week but I don't think we've topped high 20s in last 2 weeks in spite of forecasts. That's why forecasts are forecasts and not facts.
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The most common reason why forecasts do not match reality is due to strong onshore winds from False Bay in summer, which mostly affect the Southern Suburbs. Once the South Easter drops in March, temperatures tend to be more accurate. The Cape Peninsula is not quite an island, but in meteorology it's called the sea breeze effect.
 
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Splinter

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Gordon_R said:
The most common reason why forecasts do not match reality is due to strong onshore winds from False Bay in summer, which mostly affect the Southern Suburbs. Once the South Easter drops in March, temperatures tend to be more accurate. The Cape Peninsula is not quite an island, but in meteorology it's called the sea breeze effect.
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What I do not get, is that we should have dozens of years of data of actual conditions that turned into actual conditions a day later. So rather than predicting forward, how is it that we dont look backwards for these same conditions, at a point in time, and then give what happened next?

I've said, jokingly, in the past, that the best job to have is a weatherman. Why - because they are almost always wrong, and it's expected :p
 
Mortymoose

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Gordon_R said:
SABC TV showed footage of rare March flowers in Namaqualand (Nieuwoudtville), following the recent widespread rains. Mostly Brunsvigia and Haemanthus.
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I was on a one man road trip two weeks ago after dropping the MiddleBornMoose of at UCT. I never land up heading straight home and often meander up the West Coast looking for obscure things....

I went to search for a Scottish person at a roadside cafe called Bagdad about 26 kilometers East of the remote Sandveld town called Van Rhyansdorp.

Turns out the roadside cafe was shut due to Covid,

As I sat in my chariot I noticed a rather steep pass further towards the East, a slow moving truck reflecting her cumbersome presence with a sharp reflection of sunlight....

Well, what's a man to do? So I headed East to conquer the pass and was not disappointed to look back West into the valley from whence I had emerged...

3pass.jpeg

I was about to head back down when I realised I had nowhere to be, no appointments, no family, nothing so I thought to head further East along the top of the escarpment,

A signboard indicated that the town of Nieuwoudtville was ahead and that this soon to be discovered town was the Bulb Capital of the world....

"Bulb Capital of the world? Up here in the middle of nowhere?", I thought to myself, Learning something of interest always tickled me, an obscure fact to throw out at the next braaifire.....

The town of Nieuwoudtville was flat , dusty and scruffy...... but what did catch my attention was an extremely beautiful church.... a sandstone church....... this stunning structure made the drive ever so worthwhile...

1church.jpeg

2church.jpeg

Sorry for hijacking the thread, but you okes in here all seem to appreciate things of interest.... :p

As I always do after driving a new road, I research the towns and places only to my horror did I realize I missed something called the Nieuwoudtville Waterfall....... " A waterfall out here? Plunging off the escarpment to the parch Sandveld floor!"

So next time I go hurtling down the N7 I will have to detour once again..... :unsure:

Oh! don;t get me started about Heerenlogement Cave...... that's another tale.....
 
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