11 July 2021 Weather Alert: Impact Based Weather Warnings for Western Cape and Namaqua: Damaging Winds, Damaging Waves and Disruptive Snow

Weather Alert: Impact Based Weather Warnings for Western Cape and Namaqua: Damaging Winds, Damaging Waves and Disruptive Snow

Please find included the Impact Based Warning for the Western Cape and Namaqua Region of Northern Cape

Legal notice:
“This warning from SA Weather Service must be communicated as received and may not be altered under any circumstance.

It must be forwarded or communicated in its entirety and 
no portion hereof may be replicated or copied and distributed.”

Hazard Alert Level Affected Municipalities Valid from (SAST) Valid to (SAST)
Damaging Winds Yellow(L2) Beaufort West, Hantam, Karoo Hoogland, Laingsburg, Bitou, Cape Agulhas, Cape Agulhas, City of Cape town, George, Hessequa, Knysna, Mossel Bay, Overstrand, Saldanha Bay, Swartland, Table Bay, Prince Albert 12/07/21 00h00 13/07/21 00h00

Discussion: Northwesterly winds associated with the cold front, will reach average speeds of 55-60km/h gusting up to 65-70km/h over the Namakwa District and the Western Cape eastern interior from mid-morning through into early Tuesday morning. Over the offshore areas between Cape Columbine and Cape Agulhas, These wind northwesterly winds (55-60km/h gusting 70km/h) are expected from Monday morning, becoming west to southwesterly and spreading to Plettenberg Bay in the afternoon, persisting into Tuesday afternoon.

Impact: Localised damage to formal and informal settlements is possible. Fallen trees may affect properties and road travel. High sided vehicles may be at risk of falling over as result of strong crosswinds (particularly on N1, N2, N7, R321, R43). Strong north-westerly winds over the eastern parts of the province may fuel runaway fires. Offshore: difficulty in navigation for small vessels and personal water craft can be expected. Disruption of beachfront activities is possible as well as danger to rock anglers.

Instruction: Be aware of the following: – sudden cross winds if traveling especially between buildings, fallen trees or power lines. Ensure that all temporary structures are well anchored. Small boats must stay away from the open sea and seek the shelter of a harbour, river estuary or protected bay.

Hazard Alert Level Affected Municipalities Valid from (SAST) Valid to (SAST)
Damaging Waves Yellow(L2) Bergrivier, Bitou, Cape Agulhas, Cape Agulhas, Cederberg, City of Cape town, George, Hessequa, M_Kamiesberg, Knysna, Matzikama, Mossel Bay, Overstrand, Saldanha Bay, Swartland, Table Bay 12/07/21 00h00 13/07/21 00h00

Discussion: The cold front is expected to affect the Western Cape on Monday. South-westerly swell with wave heights between 4.5-6.0m and wave periods of 16 seconds are expected along the south and southwest coastline behind the cold front persisting into Tuesday afternoon. The area of concern is between Hondeklip Bay and Cape Agulhas from Monday morning, and through to Plettenberg Bay in the afternoon.

Impact: Difficulty in navigation at sea for small vessels and person water craft (e.g. kayaks) can be expected. This may lead to vessels taking on water and capsizing in locality. Disruption to beach front activities is likely.

Instruction: Be aware of large unpredictable waves along the coast. Small vessels are advised to seek shelter in harbours, bays or inlets.

Hazard Alert Level Affected Municipalities Valid from (SAST) Valid to (SAST)
Disruptive Snow Yellow(L4) Breede Valley, Cederberg, George, Hantam, Karoo Hoogland, Oudtshoorn, Witzenberg 12/07/21 00h00 13/07/21 00h00

Discussion: Forecasts indicate a spread of 05-10cm with some parts receiving 15cm of snow over the mountains of the Cape Winelands and the West Coast District (Cederberg mountain range), as well as the southern high ground in the Hantam and Karoo Hoogland municipalities (N. Cape) from Monday afternoon. The snowfall will spread to the Garden Route mountain ranges during Monday evening, persisting into Tuesday afternoon with significant impacts expected in the Outeniqua and Swartberg mountains.

SOUTH AFRICAN WEATHER SERVICE
Cape Town Weather Office
2nd Floor: Oval Office Park
Cape Town Int airport
Freight Road
Matroosfontein
Cape Town