Rain and storm for Cpt

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purple face said:
Its rained all night here by me and still raining and also freezing
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A bit of hyperbole: The temperature at CT airport is 18C at midday.

P.S. Today's phase of the event is something that they would call an 'atmospheric river' rather than a cold-front. An influx of sub-tropical moisture produces many hours of constant mild precipitation, rather than a short sharp cold frontal boundary:

pwatr_018[20230423_1800].gif

A cold-front has a different spiral shape, and orientation of the moisture band, as shown earlier last week:

pwatr_024[20230420_0000].gif

Source: https://www.cpc.ncep.noaa.gov/products/international/cpci/data/00/gfs_pwat_safrica.html
 
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The difference between an atmospheric river and a cold front is not at all easy to show. SAWS attempt is depicted below, which suggests that it is a confluence between last night's arrival of the cold front and the subtropical moisture flowing down from the north along the pressure difference. Today the synoptic chart shows that a rather weak high-pressure area is now present just inland to the east of CT. Compare that one with the chart taken at 12:00 UTC.
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The High-pressure area is now shown much further north and the next cold front is on its way.
 
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airborne said:
I went outside now and was expecting it to be horribly chilly and it was actually quite warm, despite the rain still bucketing down.
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Just been out to empty the dustbin, check on the compost heap and empty the rain gauge. The wind has dropped, it is warm but very wet with 44 mm of rain in the gauge.
 
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Geoff.D said:
The difference between an atmospheric river and a cold front is not at all easy to show. SAWS is depicted below, which suggests that it is a confluence between last night's arrival of the cold front and the subtropical moisture flowing down from the north along the pressure difference. Today the synoptic chart shows that a rather weak high-pressure area is now present just inland to the east of CT. Compere that one with the chart taken at 12:00 UTC.
The High pressure area is now shown much further north and the next cold front is on its way.
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It is semi-dry in Kenilworth this afternoon, though with a dense cloud layer. There is plenty of moisture in circulation, but not enough instability to cause precipitation until the next cold front arrives early tomorrow.

Edit: Intermittent rain, heavier around 10pm.
 
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According to tonight's TV forecasts, we are in for very heavy rain tomorrow starting in the early hours. I have diverted the rainwater out of the garden and back into the drains. ( I have no idea where the water goes when it flows into those drains though. The pipes don't empty into the road gutters anywhere that I can see. One day I might just try and trace the pipes. For all I know, they might all just couple up to the sewers.
 
It rained most of the night in Kenilworth, but seems semi-dry now. 24mm in our gauge this morning, plus 16mm during yesterday, plus 38mm on Saturday, cumulative total close to 80mm in 48 hours!

The synoptic outlook shows light NW winds for the next few days, without the cold SW winds that normally follow a front. Further rain is expected from a weaker front on Thurs 27th.

I don't expect a lot of inflow into the dams from this single event, but soil moisture levels are high compared to earlier this month, and by seasonal standards. Domestic gardens will probably not require much irrigation going into winter.

The Berg River Dam is up 4% in the last 24 hours, but this is right in the mountain catchment, and always the fastest to fill compared to the others. See: https://www.dws.gov.za/Hydrology/Unverified/RTGraph.aspx?Station=G1R004FW&Type=Flow&Rain=N

Edit: Berg River Dam up 6% in 36 hours.
 
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dj2381 said:
This odd weather has made everything in my house a bit moist.
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We haven't noticed it but I just saw a facebook post where people were mentioning the same thing ... couple of them mentioned damp toilet paper!? weird ... I guess we are just not used to high humidity.
 
So when can I play golf in Simonstown? Wednesday the earliest?
 
Geoff.D said:
According to tonight's TV forecasts, we are in for very heavy rain tomorrow starting in the early hours. I have diverted the rainwater out of the garden and back into the drains. ( I have no idea where the water goes when it flows into those drains though. The pipes don't empty into the road gutters anywhere that I can see. One day I might just try and trace the pipes. For all I know, they might all just couple up to the sewers.
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our councilor (yours as well) made a post the other day that many of these drains feed into the sewerage (illegally). So they are currently running tests where they smoke out the sewers to try and track these linked drains... keep an eye our for smoke coming up the pipes!

Mine all run into the garden, I think we haven't had a proper flood since we moved in, and even since they house was remodeled buy the previous owners. Perhaps we are in for a surprise when it happens. I have tanks on some of the drains but they are now full.
 
nulkoel said:
Hah, first weather like this we are experiencing an a new house and I thought oh no, what the hell is wrong now :X3:
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I thought maybe there was moisture coming through the roof somehow and stressing about having to fork out loads of money for repairs, lol.
 
The stairs in our apartment block are completely soaked, floor, walls and ceiling. Even though the stairs are enclosed with only a few windows and doorway at the bottom.
 
dj2381 said:
I thought maybe there was moisture coming through the roof somehow and stressing about having to fork out loads of money for repairs, lol.
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Same. I just expect the worst and wonder how much it will cost. Also had the lights trip due to a seemingly dodgy outside light, but on the plus side, pool was nice and full on Saturday already.

Looking forward to continued paranoia on Wednesday / Thursday, when the next rain arrives.
 
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