MAPPED: What the cold front headed to SA looks like, flood alert issued

2017-07-15 17:22 - Selene Brophy
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Cape Town - Cold to very cold conditions are set to hit most of South Africa as a much-anticipated storm closes in along the West Coast of the Western Cape.

The SA Weather Service says 100% rain predicted for the Cape Metropole this weekend, along with extremely cold conditions. 

An alert has been issued for localised urban flooding for the metropole region and the Overberg district on Saturday Night, 15 July into Sunday morning, 16 July. 

SEE: Weather Update: Stormy Cape to see snow, fire dangers persist to the north of SA

SAWS Chief Forecaster Ezekiel Sebego says ahead of the front, rain and showers are possible over the south-western parts of the Western Cape from Saturday, 15 July 2017.

This will spread to the remainder of the Western Cape and the western and southern parts of the Northern Cape on Sunday.  

' Twice as strong hoax' 

False WhatsApp messages warning that an approaching weekend cold front will be twice-as-strong as the storm nicknamed #DikWednesday can cause unnecessary panic, says the South African Weather Service.

The South African Weather Service says it is aware of a hoax message doing the rounds that this system will be “twice as strong as the system of June 2017.

"This is false and the public is urged to always consult the official sites of the South African Weather Service as the authoritative voice on weather and climate warnings."

Significant rainfall expected

"Rain and showers will be expected over the Eastern Cape by Sunday afternoon. Significant rainfall is expected over the south-western parts of the Western Cape during Sunday morning which may result in localized flooding in places in the Cape Metropole, Overberg and Cape Winelands Districts."

Figure 1: Accumulated precipitation (mm) expected on Sunday 16 July 2017 over South Africa (©ECMWF)

Freezing levels and snowfall 

Sebego warns freezing levels are expected to drop due to the passing cold front, allowing for snowfalls over the
mountainous areas of the Western Cape and Eastern Cape on Sunday, to as low as 1 200 to 1 400m
above sea level.

"The Western Cape and Northern Cape should brace for very cold maximum temperatures, <10°C in places, with a general decrease in temperatures expected across the rest of the country."

He says traffic disruptions can also be expected due to significant snowfall with possible closure of mountain passes in the Western Cape and Eastern Cape.

"Snowfalls are expected over the high lying areas of the province with disruptive snowfalls expected over the Sneeuberg and Winterberg. Passes such as the Lootsberg Pass and Penhoek Pass could be affected."

The public should take care in this regard, advises Sebego.

Figure 2: Accumulated snowfall (cm) expected on Sunday 16 July 2017 ©ECMWF

Gale force winds and heavy swells

As the storm moves further along, stronger interior winds can be expected over most parts of the country on Sunday.

Sebego says possible gale force south-westerly wind with speeds of approximately 70 km/h, can be expected between Cape St  Francis and East London in the Easter Cape. 

"Heavy swell in excess of 4 metres can be expected between Cape Columbine and Port Elizabeth from Saturday evening, spreading to East London by Sunday morning and reaching Kosi Bay by Monday afternoon.

"High seas with wave heights from 6 to 9 metres can be expected between Cape Point and
East London from Monday morning. We urge all beach-goers and sailors to please take note of these

Added to this, the Eastern Cape can also expect cold to very cold and wet conditions over the Province.

"The wet weather will start clearing from the west on Monday. However, due to the absence of cloud and maximum outgoing radiation, conditions will remain cold to very cold, especially over the high lying areas.

There is a 30% chance over the northern regions, with a 60% chance of rain in the southern regions
"Rainfall over the NMBMM catchment areas will not be more than 10 mm."

Improved conditions by Monday 17 July

By Monday, 17 July, the SA weather service advises that  the cold front will move to the east of the country, with conditions improving significantly across the southern and western parts.

"Isolated morning showers will be possible along the coastal areas of KwaZulu-Natal on this day, while very cold mornings with frosty conditions are expected across most of the interior. " 

What to do in a flood

- Identify the risk in your local area.
- Pepare a home emergency plan, and identify risks around your home.
- Remove leaves (from downpipes or gutters) or any other items that can increase the risk of flooding in your area.
- Have an evacuation plan. Everyone in your family has to know where to go to find shelter.
- Prepare an emergency toolkit. This should include a first aid kit, torch and portable radio with batteries, candles and waterproof matches, drinking water, a multi-tool, whistle and emergency contact numbers.

What Should I do during a flooding?

- Monitor current flood warnings. Listen to the radio for emergency warnings, evacuation advice and weather updates.
- Avoid entering floodwater unless it is necessary, and never underestimate the strength of floodwater, even if you are inside a vehicle.
- Follow all instructions from emergency authorities.
- Turn off all electricity and water and take your cellphone with you.
- Assist elderly and disabled neighbours.

What Should I do after the flood?

- Before entering your house, wait until the water has dropped below floor level.

- Check with electricity and water authorities to know whether it is safe for you to use these resources.

- Be aware of contamination if water sources have been flooded; this could be unsafe to drink.

- In addition – JUST IN –WC average dam level currently 17.6%.   

Important Emergency contact numbers:

City of Cape Town: 107 landline or 021 480 7700
Police Flying Squad: 10111
Ambulance: 10177
City of Cape Town General Emergency: 107
Cellphone Emergency: 112 (MTN, Vodacom, Cell C and Telkom)
Red Cross Children's Hospital Poison Line & the Tygerberg Hospital Poison Information Centre: 0861 555 777 
Western Cape Government: 0860 142 142
Sea Rescue: 021 449 3500
Mountain Rescue: 021 948 9900
Disaster Management: 080 911 4357
Eden District:  044 805 5071
Central Karoo:  023 414 2603
West Coast: 022 433 8700
Overberg: 028 271 8111

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