HAMNET Report 11 June 2017

It has been a tumultuous week for the Western and Southern Cape. The warnings started going out last Sunday, when our maritime connections started to talk about a severe frontal system hitting the Western Cape on Wednesday, with storm strength winds up to 90 kph, and severe rain. The WeatherSA forecasters followed soon after with predictions of up to 75mm of rain between Tuesday evening and Thursday midday, snow, and extreme cold over the Cape and the Overberg. Radio amateurs shared warnings to drop any telescoping antenna systems they had, or check the guying involved.

The NSRI was not far behind, with warnings of very heavy swells up to 12 metres or more in height along the West Coast, the Cape Coast, and Southern and Eastern Cape Coasts. All seamen were advised to stay off the sea, particularly because the end of the week saw the full moon Spring tide, which brings higher than  normal high tides, and stronger currents, including very strong rip currents. Winds of up to 120kph were forecast for Cape Agulhas!

The South African Weather Service followed it all up with their formal Severe Weather Report for 7 and 8 June, covering heavy rain, snow falls, gale force winds and very high seas!  Synoptic charts of the  trough of low pressure and the cut-off low prolonging the rain fall were displayed.

We were well and truly warned!

Tuesday started a nice day in the Cape, with wispy high cloud, and filtered sun. By the evening, clouds were gathering and the wind started to gather speed from the North-west, blustery and unsettling, followed by the rain in squalls at about 22h00 our time that evening.

For the rest of the night, gusting winds took out trees, ripped off branches around the Cape,  whipped up the foamy surf, which crashed the Sea Point promenade, and flooded the car parks there. The fairly horizontal rain continued on and off all day, which may have confused all the rain gauges, unable to catch rain that wasn’t raining downwards, so the rain figures weren’t as impressive as expected. One or two areas experienced up to 50mm rain on Wednesday, but for the rest, measurements of 15 to 30mm were made.

Disaster Management crews were magnificent, responding to reports of downed trees and blocked roads as soon as they were received, and half of the chaos was cleared up by daylight the next morning. Rain and wind carried on intermittently all Wednesday, but the Cape was prepared, because Schools had been closed for the day in preparation, and many businesses had told their workers to stay at home.

HAMNET cancelled our monthly meeting for that night, and arranged a special call-in at 19h30 that evening on our 145.700 repeater on Constantiaberg, followed by a call-in on 145.225 simplex, and it was gratifying to see and hear how many operators were there to report on their areas, and make contact on simplex. Regional Director Grant Southey ZS1GS issued a directive to local amateurs, and requested other divisions to monitor 3770kHz and 7110kHz LSB, and 5260kHz and 10125kHz USB if at home, and to be available to assist with communications if needed.

Wednesday night was less dramatic, as far as wind and rain was concerned, and by midmorning Thursday, the Cape was licking its wounds and starting to settle down.

What nobody had paid much attention to were the very extreme Berg Wind conditions occurring in the tinder-dry Southern Cape, and so it was that multiple fires started up in the region of Knysna, Belvedere, and Brenton, causing a far greater humanitarian disaster than we experienced in the Western cape. You have all been following the press reports, so will know of the hundreds of dwellings burnt out, properties devastated, and some lives lost.

When it became clear that communications were proving difficult in the area,  National Director of HAMNET Paul van Spronsen ZS1V was called in by Western Cape Provincial Disaster Management, to establish communications between Eden Disaster Management Centre and the Emergency Management Centre at Tygerberg. The ionosphere of course was not playing along, 80 and 40 metre bands were not of much good, and 60 metres not available to most. The usual telephony infrastructure was soon back online and so the focus changed to ensuring that the Cape Nature fire fighters who were being deployed from Cape Town to assist and who operate on midband frequencies, would have the necessary communications in the operational area. On Friday, a team of 3 HAMNET operatives from division 2 deployed to the area to assist with message handling and the operation of a Cape Nature portable repeater. WhatsApp signals were whizzing back and forth, and, at any time, I have been seeing 60 to 80 messages being spread amongst the members of the groups, together with many pictures, videos and voice messages. Of course these only work where the internet, phone lines and cell towers are not damaged, so have been of use to those at a bit of a distance from the centres of high impact.

As I write this on Saturday afternoon, I have 50 messages on WhatsApp, referring to the N2 closed due to poor visibility due to smoke, fires having reached the East end of Groenvlei, spreading against the winds coming in from the West-north-west, and little or no rain in  the area to help dampen the embers. Amateurs along the South Coast continue to maintain listening watches on the repeaters and on simplex where repeaters don’t reach. Gale Force winds from the West have forced the grounding of the many helicopters available to dump water on the fires. Buffalo Bay is also being threatened, and, in some places, electricity has been cut to areas that might suffer cable damage due to fire.

Disaster Risk Management at Tygerberg has despatched the Metro Four disaster bus to Knysna, and radio amateurs may be called to help man it once there.

Another cold front has arrived in the Western Cape today (Saturday), and 5 to 10mm of rain have been measured so far, but not much has filtered through to the Eden Disaster Management area, so the fires continue unabated. Our thoughts are with those who have lost so much in the last four days.

This is  Dave Reece ZS1DFR reporting for HAMNET in South Africa.