Closure of the SAWDOS Blog - 31 March 2013

This will be the final posting on the SAWDOS Blog.

This blog will no longer be updated but will remain available for research and historical purposes.

Please note:

1. SAWDOS will still be active on our FACEBOOK GROUP PAGE at: http://www.facebook.com/groups/374316165928426/ 

2. SAWDOS will still be active on our TWITTER ACCOUNT at: @SAWDOS1

3. For those who wish to see the reasons for closing of the SAWDOS Blog click HERE , HERE, and HERE.

Looking forward to re-meet many of you on Facebook and Twitter!

J. Terblanche
Founder: SAWDOS + SAWDIS
Mossel Bay
31 March 2013

SA National Severe Weather Warnings: 31 March 2013 16h00 SAST

• Current warning: Northen Cape
• Updated: 31/03/2013 15:45:37
• Validity: 2013-03-31 to 2013-04-01
• Type: Warning. Take action
• Subject: Heavy rainfall
• Detail: 1. Heavy rain is possible in places over the central and southern parts tonight and over southern part Monday.

• Current warning: Western Cape
• Updated: 31/03/2013 15:45:37
• Validity: 2013-03-31 to 2013-04-01
• Type: Warning. Take action
• Subject: Very Rough Seas and Heavy Rainfall
• Detail: 1. Very rough seas with wave heights between 4 to 6m are expected between Cape Point and Cape Agulhas. 2. Heavy rain is possible in places over Central Karoo tonight and eastern half of Western Cape Monday.

• Current warning: All other Provinces
• Updated: 31/03/2013 04:53:54
• Validity: 2013-03-31 to 2013-03-31
• No warnings nor advisories in effect
• Subject: No alerts
• Detail: No Alerts

- SAWS

SA Weather Satellite Images: 31 March 2013 16h00 + 18h00 SAST

- Eumetsat (Click on images for larger view.)

Fire leaves 120 people homeless in Langa

An inferno was reported at 23:45 on Saturday, 30 March 2013 at Lerotholi Avenue in Langa.

Upon arrival of the firefighters it was established that shacks were engulfed with flames.

The blaze destroyed 31 shacks leaving 120 people displaced. All persons were accounted for and no injuries were sustained.

The City’s disaster response teams assisted the fire victims with the supply of food parcels, blankets, baby packs, clothing and building material.

The City’s Disaster Risk Management Centre encourages residents to be fire safe when working with open flames. When going to bed, residents should isolate electrical devices and extinguish gas burners, candles, lamps and paraffin stoves in order to prevent fires.

For more information on how to prevent fires please visit City’s Disaster Risk Management Centre on www.capetown.gov.za on www.capetown.gov.za/disaster.

End

Issued by: Disaster Risk Management Centre, City of Cape Town



Source : Wilfred Solomons-Johannes, Head: Systems Integration, Special Projects & Disaster Operations, Disaster Risk Management Centre, City of Cape Town

Strong winds wreaks havoc – trees uprooted across Cape Town

Yesterday the gale force winds that were experienced in Cape Town wreaked havoc.

GARDENS: The winds have blown down trees at the Mount Nelson Hotel, Orange Street in Gardens.

BERGVLIET: A tree had fallen resulting in the obstruction of traffic adjacent to 13 Fountain Road, Bergvliet.

OTTERY: A tree was blown down touching on overhead electricity wires resulting in arching at 1 Wegner Avenue, Ottery.

CONSTANTIA: The wind blown down branches and a tree onto the roadway causing traffic congestion at 1 Dreyer Close, Constantia.

CONSTANTIA: A tree standing on the greenbelt has fallen over that resulted in damaging a boundary wall and an electric fence. The City of Cape Town will be clearing the area today as the owner was not present to gain access to the premises.

TOKAI: A tree fell over obstructing the roadway near 47 Zwaanswyk Road, Tokai.

The City’s law enforcement authorities closed off the roadways and redirected traffic to make use of alternative routes in the interest of public safety.

The standby teams of the City’s Parks Department were activated that cleared up the branches blown down and trees that were fallen.

In another incident a wendy house collapsed due to strong winds at St Yusuf Street Macassar yesterday afternoon. The City’s disaster response teams assisted the family consisting of 3 adults and 1 child with food parcels, clothing, blankets and building material.

End

Issued by: Disaster Risk Management Centre, City of Cape Town

Wilfred Solomons-Johannes, Head: Systems Integration, Special Projects & Disaster Operations, Disaster Risk Management Centre, City of Cape Town

Strong winds render scaffolding of Cape Town’s tallest skyscraper unstable

At 17:30 on Saturday, 30 March 2013 numerous reports were received from eyewitnesses regarding scaffolding becoming unstable at the Portside building in the Cape Town CBD.

Upon arrival of the City’s disaster response teams and the building inspectorate it was established that the scaffolding on the construction site has fallen to the ground.

The City’s law enforcement agencies have cordoned off the area surrounding the construction site in the interest of public safety.

The City’s building inspectorate has ordered the contractors, Murray & Roberts, to effect emergency repairs and stabilise the site without delay due to gale force winds that were experienced.

The Portside building currently under construction bordering Buitengracht, Hans Strijdom, Bree and Mechau Street, will be Cape Town’s newest and tallest skyscraper.

The building will be featuring 32 floors, over 52,000 m² of office space; 1,200 m² of retail and banking space, easily accessible from all sides on the ground level, and 1,382 parking bays.

End

Issued by: Disaster Risk Management Centre, City of Cape Town



Source: Wilfred Solomons-Johannes, Head: Systems Integration, Special Projects & Disaster Operations, Disaster Risk Management Centre, City of Cape Town

Five dead in SA Air Force A109 crash

 All five people on board a South African Air Force A109 Light Utility Helicopter died when their aircraft crashed in the Kruger National Park yesterday evening.

According to Brigadier General Xolani Mabanga, SANDF Director Corporate Communications, the helicopter was on a scheduled aerial patrol of the Kruger National Park as part of the Operation Rhino anti-rhino poaching operation.

The helicopter went down at around 19:00, killing all on board. It is not yet clear what caused the crash, but an investigation into the incident has been launched.

“The Minister of Defence and Military Veterans, Ms Nosiviwe Mapisa-Ngqakula, the Chief of the SANDF, General Solly Shoke and the Chief of the SA Air Force, Lieutenant General Zimpande Msimang express their heartfelt condolences to the families, loved ones and friends of the deceased members,” the South African National Defence Force said in a statement.

Three of the South African Air Force’s 30 AgustaWestland A109s have been involved in crashes. A May 2009 crash into Woodstock Dam that killed all three crewmembers on board was deemed to have resulted from pilot error while two hard landings in November and December 2010 resulted in the type being briefly grounded. The 2010 incidents were due to tail rotor failure and a broken swash plate control rod. Last year the Air Force said that all A109 problems had subsequently been identified and rectified and the aircraft were flying normally.

Earlier this year, two BK-117 helicopters from 15 Squadron’s C Flight were known to be providing aerial surveillance capabilities as part of Operation Rhino.

The A109 crash is the latest in a string of incidents to hit the South African National Defence Force. On December 5, 2012, all eleven people on board an Air Force C-47TP Turbo Dakota were killed when their aircraft crashed in the Drakensberg in bad weather in the worst non-combat crash in 50 years. Last weekend 13 soldiers were killed in a firefight with Central African Republic rebels and 27 injured.


- DefenceWeb

Closure of the SAWDOS Blog - 31 March 2013

It is a day of mixed emotions for the Founder of the  SAWDOS and the SAWDOS Blog. The first blog (S.A. Weather and Disaster Information Service - with hits to date) was created on the 8 October 2008.  A new blog (SA Weather and Disaster Observation Service with hits to date) with subsequent name change was created on the 1 January 2012.

Today (31 March 2013) is the end of the road for the SA Weather and Disaster Observation Service Blog.  It is the end of an era but the beginning of a new venture. The time has come for one unified organization to keep the public informed about severe weather conditions by means of real time weather observation. The  statement available HERE set out the current merger/amalgamation plans.

SAWDOS has indicated in the past that restructuring of the SAWDOS Blog is essential. The topic is available HERE. In the mean time discussions took place between HAMNET, SAWDOS and Kobus Botha (Weatherphotos). An agreement has been reached as set out by HAMNET in their statement.

The use and updating of the SAWDOS blog as of 1 April 2013 will constitute a duplication of weather observation information. The web-site of Kobus Botha at www.weatherphotos.co.za contains all the necessary information pertaining to the weather in South Africa. Disaster information and communications will be available on the HAMNET web, Facebook and Twitter pages.

The Twitter and Facebook pages of the SAWDOS also contain valuable information and images supplied by the public. As a result of the merger/amalgamation the SAWDOS Blog will be closed  at the end of the day on the 31 March 2013. The SAWDOS Twitter and SAWDOS Facebook pages will remain active until the merge and amalgamation has been completed.

SAWDOS would like to recommend that subscribers and users of the SAWDOS Blog migrate to Kobus Botha's Weather Photos of South Africa so as to get acquainted with the workings of the site. Kobus has an excellent site with information and data. Click HERE to visit Weather Photos of South Africa.

SAWDOS, HAMNET and Weatherphotos will keep the public informed on a regular basis as to changes that will occur in the next few months.

I would like to take the opportunity to thank all our readers, weather observers, the media, NGO'S, Disaster Management, Radio Amateurs and others who supported/contributed to the SAWDOS Blog in the past. You all made the Blog a source of information that I believe was of great benefit to South Africans and citizens abroad and around the world.  A BIG THANK YOU TO YOU ALL!!

Johan Terblanche
Founder:  SAWDOS and SAWDIS
Mossel Bay
31 March 2013

SA Air Force Agusta 109 helicopter crashed just North of Satara, Kruger National Park

 Agusta 109 File Photo



An SA Air Force Agusta 109 crashed just north of Satara just after 18h00 last night. One pilot + 4 other SANDF members on board. All deceased.


It is believed that  the helicopter was as part of "Anti-Rhino-Poaching" operation at the time of the crash.  No further details currently available.

The SA Air Force aviation safety record is getting worse by the day. Several Agusta 109's and other SAAF aircraft crashed in the past.  HERE is a record of SAAF crashes that occurred recently.

SA National Severe Weather Warnings: 31 March 2013 04h00 SAST

• Current warning: Eastern Cape
• Updated: 31/03/2013 04:53:54
• Validity: 2013-03-31 to 2013-03-31
• Type: Warning. Take action
• Subject: Heavy Rainfall and Very Rough Seas
• Detail: 1. Heavy swell in excess of 4m is expected between Plettenberg Bay and Port Alfred spreading Sunday to Port St Johns. 2. Heavy rain is possible in places over the central and eastern parts as well as a watch over northwestern and southeastern parts Sunday.

• Current warning: Northern Cape
• Updated: 31/03/2013 04:53:54
• Validity: 2013-03-31 to 2013-03-31
• Type: Warning. Take action
• Subject: Heavy rainfall
• Detail: 1. Heavy rain is possible in places over the southeastern part tonight and a watch for southeastern, central and northwestern parts Sunday.

• Current warning: Western Cape
• Updated: 31/03/2013 04:53:54
• Validity: 2013-03-31 to 2013-03-31
• Type: Warning. Take action
• Subject: Gale SE, Very Rough Seas and Heavy Rainfall
• Detail: 1. Very rough seas with wave heights between 4 to 6m are expected between Cape Point and Port St Johns. 2. A gale force SE wind of 65 to 70 km/h is expecetd between Cape Point and Cape Agulhas in morning. WATCHES: -------- 3. Heavy rain is possible in places Central Karoo of Western Cape.

• Current warning: All other Provinces
• Updated: 31/03/2013 04:53:54
• Validity: 2013-03-31 to 2013-03-31
• No warnings nor advisories in effect
• Subject: No Alerts
• Detail: No Alerts

- SAWS

SA Weather Satellite Images: 31 March 2013 (05h00 + 05h30 SAST)

- Eumetsat and SAT24

Possible 24 Hour Rainfall: South Africa

- 1stweather.com

GFS Medium Range Forecasts of Vertical Velocity and Precipitation: South Africa

- U.S. National Center for Environmental Prediction (NCEP)

SA Sea Level Synoptic Chart : South Africa

- SAWS

Why Mars exploration will be suspended in April, 2013

Planet Mars mission controllers are preparing to suspend explorations of the Red Planet via spacecraft for 17 to 21 days in April, 2013.

The planet Mars was a bright red “star” in our sky on August 5, 2012, when the newest Mars rover Curiosity made its dramatic descent to the surface of the Red Planet. But by early April 2013, when Mars and Venus will sweep near each other after sunset, what otherwise would be an awesome conjunction of two cool planets will lost in the sunset glare. Mars has now left the evening sky, on its way to passing behind the sun as seen from Earth on April 18. Around the time this happens – for 17 to 21 days in April, 2013 – NASA will be forced to temporarily suspend its exploration of Mars.

 Artist’s concept of Mars conjunction on April 18, 2013. 

 The sun will be between Earth and Mars. This geometry of worlds occurs – called a “conjunction of Mars” – happens about every 26 months. During a Mars conjunction, radio transmissions between Earth and Mars may be corrupted by the intervening sun. So NASA Mars missions have a moratorium on sending commands to spacecraft on the surface of Mars or in orbit around Mars. Image via NASA.

Curiosity self-portrait Feb. 3, 2013 via NASA

NASA said in a press release on March 20:

The sun can easily disrupt radio transmissions between the two planets during [Mars and the sun's] near-alignment [as seen from Earth]. To prevent an impaired command from reaching an orbiter or rover, mission controllers at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., are preparing to suspend sending any commands to spacecraft at Mars for weeks in April. Transmissions from Mars to Earth will also be reduced.

From the standpoint of earthly observers, Mars conjunctions are not identical from year to year. As seen from Earth, Mars could be nearer to the sun at a given year’s conjunction, or farther away, and the sun might be in an active or a quiet phase of its 11-year cycle of activity.
This year, Mars and the sun will be relatively close together on the sky’s dome at conjunction, in contrast to some other years. Meanwhile, the sun is near the peak of its cycle, albeit a mild peak, in contrast to some. So the chances for radio interference between Earth and Mars are good.

Curiosity self-portrait August 8, 2012. 

The rover will be out of touch with NASA in April 2013, as all Mars missions are suspended for up to three weeks. Image via NASA.Click here to expand image.

But the biggest difference for this 2013 conjunction is having Curiosity on Mars, according to NASA scientists. Odyssey – a robotic spacecraft orbiting Mars since 2001 – and the Mars Reconnaissance Orbiter – orbiting Mars since 2006 – relay almost all data coming from Curiosity and an older rover, Opportunity. NASA said:

Transmissions from Earth to the orbiters will be suspended while Mars and the sun are two degrees or less apart in the sky, from April 9 to 26, with restricted commanding during additional days before and after.

Read more about NASA’s plans for the upcoming conjunction of Mars with the sun

Bottom line: NASA mission controllers will suspend Mars exploration via spacecraft for 17 to 21 days in April, 2013. At that time, Mars will be behind the sun as seen from Earth. The space engineers are worried that interference from the sun could impair radio transmissions between Earth and Mars, causing the spacecraft to execute a faulty command.

HAMNET Weekly Report 31/03/2013

The Suicide Gorge kloofing or trail route in the Nuweberg Nature Reserve near Grabouw, is a frequent rescue site. Hamnet has been invited by the MCSA Hottentots Holland chapter to participate in a communication and mapping exercise in the area to improve our collective knowledge of the area.

We will deploy our four MT-AIO man portable APRS beacons into various parts of the gorge and it is our aim to be able to track them and plot their positions at the Nuweberg Nature conservation office. I need the following volunteers to participate in this exercise:

- 2 four wheel drive vehicles capable of acting as digipeaters

- 1 foot mobile operate capable of acting as a digipeater

- 1 base operator to receive, log and plot the positions

HWC has a Tinytrak 4 that can be interfaced to a radio to fulfil one of the above rolls and I have another TT4 that could be configured to do the same. We do not however have a comprehensive set of cables for connecting the TT4 to every possible kind of radio. If you are capable of acting as a digipeater (eg. Kenwood TMD-700/710, TH-D72) but do not have a 4x4, or you have a 4x4 and are not capable of acting as a digipeater, please respond anyway. We could form two man teams to solve the complete problem.

Paul also indicated that the consignment of MT-AIO portable APRS units has worked so well since purchasing them, that he is now considering purchasing another couple of units. They work exceptionally well in the mountainous terrain they need to cover in search & rescue activities.

The plan is to deploy the foot mobile operative along the top of the gorge in order to digipeat the signal from the gorge out to a mobile/vehicle based digipeater and from there to the base. We will deploy the two 4x4s in different parts of the nature reserve to see where the most appropriate position to give us the coverage we need, is.

The exercise will start early on Sunday morning. Arrangements have been made that those who wish to may camp over from the Saturday evening, when there will be a bit of a social/braai.

For the benefit of readers not involved in amateur radio, a digipeater is a repeater using digital modes which use low power and very accurate, effective and useful in any type of emergency communication! With SAWDOS and HAMNET merging on Facebook at a later stage, we wish to educate non amateur readers on terms, phraseology and items we use on a regular basis in our operations.

Reporting for Hamnet, this is Francois Botha, ZS6BUU.

A Different View of Home

While observing the turbulent outer atmosphere of the Sun, or corona, Solar Terrestrial Relations Observatory B (STEREO-B) gathered a novel view of our home planet and a celestial visitor in the inner solar system. Comet PanSTARRS was visible to the naked eye from Earth’s northern hemisphere at the time, though STEREO might have had the better view.

The Heliospheric Imager (HI) on STEREO-B captured this image of PanSTARRS and Earth on March 13, 2013. At the time of the image, PanSTARRS was about 0.3 astronomical units (AU) from the Sun and about 1.1 AU from the Earth. Astronomical units are roughly the distance from the Sun to the Earth: 150 million kilometers or 93 million miles.

The HI instrument observes the area just off the limb of the Sun (left) in order to detect the faintly visible light of the solar wind and coronal mass ejections (CMEs) as they blow out into the solar system. STEREO-B was on the far side of the Sun from the Earth, at about a 150 to 160 degree angle from the Earth-Sun line. Puffs of solar wind and from a CME are visible in a video made from the same images in March.
In the image and video, PanSTARRS and its tail are the bright, wide mass in the center of the image. A coronal mass ejection is developing on the Sun’s limb (left), and Earth is to the right of the comet. The white dots in the background are stars. The vertical lines across the image are artifacts of the imager; the light of the comet, the Earth, and some planets and stars is too bright for an instrument trying to observe the faint light of the Sun’s atmosphere.

Videos of the comet and solar eruptions are available by clicking here and here. To see the location of the satellites, comet, and planets, click here.
 

Image by NASA/GSFC/STEREO. Caption by Michael Carlowicz.

Instrument: 

STEREO -  NASA

SA National Severe Weather Warnings: 30 March 2013 16h00 SAST

• Current warning: Eastern Cape
• Updated: 30/03/2013 15:55:31
• Validity: 2013-03-30 to 2013-03-31
• Type: Warning. Take action
• Subject: Heavy Rainfall and Very Rough Seas
• Detail: 1. Heavy swell in excess of 4m is expected between Plettenberg Bay and Port Alfred spreading Sunday to Port St Johns. 2. Heavy rain is possible in places over the central and eastern parts as well as a watch over northwestern and southeastern parts Sunday.

• Current warning: Kwazulu Natal
• Updated: 30/03/2013 15:55:31
• Validity: 2013-03-30 to 2013-03-30
• Type: Warning. Take action
• Subject: Heavy Rainfall
• Detail: 1. Heavy rain is possible in places over the southern parts.

• Current warning: Northern Cape
• Updated: 30/03/2013 15:55:31
• Validity: 2013-03-30 to 2013-03-31
• Type: Warning. Take action
• Subject: Heavy rainfall
• Detail: 1. Heavy rain is possible in places over the southeastern part tonight and a watch for southeastern, central and northwestern parts Sunday.

• Current warning: Western Cape
• Updated: 30/03/2013 15:55:31
• Validity: 2013-03-30 to 2013-03-31
• Type: Warning. Take action
• Subject: Gale SE, Very Rough Seas and Heavy Rainfall
• Detail: 1. Very rough seas with wave heights between 4 to 6m are expected between Cape Point and Port St Johns. 2. A gale force SE wind of 65 to 70 km/h is expecetd between Cape Point and Cape Agulhas in morning. WATCHES: -------- 3. Heavy rain is possible in places Central Karoo of Western Cape.

• Current warning: All other Provinces
• Updated: 29/03/2013 15:42:05
• Validity: 2013-03-29 to 2013-03-30
• No warnings nor advisories in effect
• Subject: No Alerts
• Detail: No Alerts.

- SAWS

SA Weather Satellite Image: 30 March 2013 17h00 SAST

- Eumetsat (Click on image for larger view.)

“Good Friday” fires result into misery for Cape Town families – over 100 people homeless

KALKFONTEIN: A blaze occurred at 18:56 on Friday, 29 March 2013 at Elmaree Street in Kalkfontein. Firefighters from Kuils River, Belhar, Strand, Bellville, Lansdowne, Mfuleni, Goodwood, Ottery; and seasonal firefighters on standby at the Epping Fire Training Academy were dispatched to the incident. The blaze destroyed 21 shacks that spread and affected 1 formal dwelling. The firefighters managed to extinguish the inferno at 20:30 and made the area safe.

GUULETHU: A fire occurred at 20:45 on Friday, 29 March 2013 at the Lusaka Informal Settlement situated off Old Klipfontein Road, in Gugulethu. The City dispatched firefighters from the Lansdowne Road, Gugulethu, Strand, Belhar and Gugulethu fire stations that arrived at 20:52. The firefighters brought the fire under control at within 17 minutes within 17 minutes [21:08] from their time off arrival. The fire destroyed 4 informal shacks that were backyard dwellings. Prior to the arrival of the emergency crews the occupants attempted to extinguish the blaze with buckets of water. It is suspected that the fire was started from a short circuit in electrical wiring insulation.

FISANTEKRAAL: At 21:42 on Friday, 29 March 2013 a fire occurred at the Fisantekraal Informal Settlement area near Durbanville. Firefighters from Kraaifontein, Durbanville, Milnerton, Goodwood, Brackenfell, Bellville stations were dispatched to the incident. The inferno destroyed 11 shacks and left 41 people displaced that include 25 adults and 16 children. It is suspected that the fire was caused by a lighted paraffin stove that overturned and ignited.

MASIPHUMELELE: At 23:59 on Friday, 29 March 2013 a fire was reported at Site 5: Masiphumelele Informal Settlement, c/o Kanana and Masibolo Streets. Firefighters from Fish Hoek, Simon’s Town, Constantia, Lakeside and Ottery were dispatched to the scene and brought the fire under control at 01:01 this morning [Saturday, 30 March 2013]. The fire destroyed 25 shacks that spread and also destroyed 3 formal houses. This morning 58 adults and 2 babies were left displaced following the fire. One adult female suffered smoke inhalation and was provided with treatment by paramedics on-scene. One adult male that was standing on a roof top of a shack fell – it is suspected that he fractured his ankle and was transported to False Bay Hospital for further medical treatment. The firefighters brought the fire under control and extinguish it at 02:40 this morning [Saturday, 30 March 2013]. As a result 60 people were left homeless (58 adults and 2 babies). It is suspected that the cause of the fire was as a result of open flames overturning and igniting bedding.

Disaster response teams at hand

The City’s disaster response teams rushed into action and assisted the fire victims with the supply of food parcels, blankets, baby packs, clothing and building material.

The City’s Disaster Risk Management Centre encourages residents to be fire safe when working with open flames. When going to bed, residents should isolate electrical devices and extinguish gas burners, candles, lamps and paraffin stoves in order to prevent fires.

For more information on how to prevent fires please visit City’s Disaster Risk Management Centre on www.capetown.gov.za on www.capetown.gov.za/disaster.

End

Issued by: Disaster Risk Management Centre, City of Cape Town

Source: Wilfred Solomons-Johannes, Head: Systems Integration, Special Projects & Disaster Operations, Disaster Risk Management Centre, City of Cape Town

Cold-front SW-Cape, and weak upper air trough (30 March - 2 April 2013)

The appearance of the deep frontal-low (bottom image)  and cold-core upper trough (top image) is quite obvious from this mornings satellite images.  We could be in for and interesting weekend.  First real winter cold front approaching?  Dropping temperatures?  Strong South Easterly Wind? Possible Cut Off Low? Thunderstorms to the East? Heavy Rain? This Easter weekend might just be the turn from Autumn to an early Winter spell.

All SAWDOS Weather Observers and non SAWDOS weather observers are hereby requested to report severe thunderstorms, heavy rain and other adverse weather conditions in their area of observation.  Be alert and send observations to the SAWDOS as we will in turn publish the observations to the benefit of the general public.

There is really no better way than real time weather observations by the public when it comes to reporting severe weather in an area.

Send information to:

SMS, MMS messages to: 076 251 3482 (only text messages)

Email photos and information by clicking HERE.

If you observe any strange weather or disaster send the info to the SAWDOS for publication. Do not assume that the SAWDOS knows for certain that severe weather has occurred in your area. Never assume that your weather observation report is not important.

We also remind our readers that the SAWDOS utilize the following social media formats to keep our readers informed :

SA Weather and Disaster Observation Service Blog - http://sawdis1.blogspot.com/

SAWDOS Twitter - http://sawdis1.blogspot.com/p/sawdis-twitter.html

SAWDOS Facebook Group - http://www.facebook.com/groups/374316165928426/

Please note that any of the above could be used during severe weather to keep the public informed or to notify the SAWDOS of an event.

Johan Terblanche
Founder: SA Weather and Disaster Observation Service
Mossel Bay
30 March 2013

SA National Severe Weather Warnings: 30 March 2013 04h00 SAST

• Current warning: Eastern Cape
• Updated: 30/03/2013 05:10:12
• Validity: 2013-03-30 to 2013-03-30
• Type: Warning. Take action
• Subject: Heavy swell along the south coast with possible heavy rain in places over the interior
• Detail: 1. Heavy swell in excess of 4m is expected between plettenberg Bay and Port Alfred. WATCH: 2. Heavy rain is possible in places over the central parts tonight spreading to the east from tomorrow.

• Current warning: Kwazulu Natal
• Updated: 30/03/2013 05:01:40
• Validity: 2013-03-30 to 2013-03-30
• Type: Watch. Be prepared
• Subject: Heavy rain in the extreme south
• Detail: 1. Heavy rain is possible in places over the extreme southern parts.

• Current warning: Northern Cape
• Updated: 30/03/2013 05:01:40
• Validity: 2013-03-30 to 2013-03-30
• Type: Watch. Be prepared
• Subject: Heavy rain in the south-east
• Detail: 1. Heavy rain is possible in places over the south-eastern parts.

• Current warning: Western Cape
• Updated: 30/03/2013 05:09:55
• Validity: 2013-03-30 to 2013-04-01
• Type: Warning. Take action
• Subject: Heavy swell, gale force winds and heavy rain (from Sunday)
• Detail: 1. Heavy swell in excess of 4m is expected between Lambert's Bay and Plettenberg Bay. 2. A gale force SE wind of 65 to 70 km/h is expected between Cape Point and Cape Agulhas. ADVISORY: 3. Heavy rain is possible in places except in the south-east, from Sunday evening into Monday

• Current warning: All other Provinces
• Updated: 29/03/2013 15:42:05
• Validity: 2013-03-29 to 2013-03-30
• No warnings nor advisories in effect
• Subject: No Alerts
• Detail: No Alerts

- SAWS

SA Weather Satellite Images: 30 March 2013 07h00 SAST

- SAT24 (Click on images for larger view.)

Possible 24 Hour Rainfall: South Africa

- 1stweather.com

GFS Medium Range Forecasts of Vertical Velocity and Precipitation: South Africa

- U.S. National Center for Environmental Prediction (NCEP)

SA Sea Level Synoptic Chart : South Africa

- SAWS

Seacom cable repair operation continues

Johannesburg - Cable company Seacom was still working on repairing the damaged undersea cables that had disrupted internet services, a statement on its website said on Friday.

Internet service providers have been reporting cuts to their systems since 22 March and Seacom has had to re-route its disrupted lines.

International internet connectivity between Sub-Saharan Africa and Europe has largely been affected.

In the statement, posted on Thursday, Seacom said it was in the process of restoring transmission to affected customers.

"We again apologise to those customers who continue to be impacted following the further fault on the restoration system SMW4," said Seacom.

Earlier in the week, the company confirmed it had received reports about three people arrested for cutting Seacom cables in Egypt.

Seacom said it did not believe that the initial disruptions were a sabotage operation.

"We think it is unlikely that the damage to our system was caused by sabotage. The reasons for this are the specific location, distance from shore, much greater depth, the presence of a large anchored vessel on the fault site which appears to be the cause of the damage and other characteristics of the event," said Seacom.

The incident was still being investigated.

Seacom said full transmission would likely be restored by early April.

- SAPA/News24

Ice on the Caspian Sea

The Caspian Sea isn’t really a sea but in fact a giant lake that spans roughly 1,000 kilometers (600 miles) from north to south. In the winter, ice often forms over the lake’s northernmost reaches, while the central and southern parts remain ice free. Temperatures are generally lower in the north, so you might guess that the ice owes its existence purely to the higher latitude. But the reality is more complex: From north to south, the Caspian Sea also exhibits differences in salinity and depth.

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured a natural-color image of ice on the northern Caspian Sea on March 7, 2013 (top). The map (bottom) shows the bathymetry, or depth, of the northernmost part of the sea. Darker shades of blue indicate greater depth.
The differences in depth in the Caspian Sea are stark. Most of the northern part of the sea has a depth of 10 meters (30 feet) or less. Roughly west of Poluostrov Mangyshlak (the Mangyshlak Peninsula, or Tüpqaraghan Tübegi), depth begins to increase. In the southern part of the Capsian Sea, depth is measured in hundreds of meters, with some areas exceeding 1,000 meters (3,000 feet).

The Caspian Sea also shows varying levels of salinity. Overall, it is about one-third as salty as the ocean. The water is saltiest in the south and freshest in the north. Roughly 130 rivers feed the giant lake, and nearly all of them enter from the north or west. The biggest is the Volga, which enters the Caspian Sea from the northwest, bringing a generous supply of fresh water.

Fresh water freezes at 0 degrees Celsius (32 degrees Fahrenheit), but since the Caspian is brackish, temperatures must fall below that for salt water to freeze. For every five parts per thousand salt content (salinity), the freezing point drops by 0.28 degrees Celsius (0.5 degrees Fahrenheit).

A lower freezing point is not the only impediment to the freezing of salt water. Salty water behaves differently than fresh water, hampering the formation of an ice layer at the surface.

Ice floats because liquid water is denser than ice. But liquid water is not uniform in its density. Fresh water is densest at 4° Celsius (39° Fahrenheit), several degrees above its freezing. As it cools below 4°C, it starts to rise toward the surface. If a layer of ice has already formed at the lake surface, this cooling and rising water can easily freeze onto the bottom of that ice.

Salt water, in contrast, typically reaches its maximum density closer to its freezing point. Because salt water usually sinks just before it is about to freeze (rather than rising), more of the water column must cool down before salty water can form an ice layer.

In the shallower part of the Caspian basin, water more readily cools throughout the water column than in the deeper parts. So the shallower northern section facilitates freezing.

1. References

2. GRID-Arendal Caspian Sea Salinity. Accessed March 28, 2013.
3. International Institute for Caspian Studies Caspian Sea. Accessed March 28, 2013.
4. National Snow and Ice Data Center Salinity and Brine. Accessed March 28, 2013.

NASA Earth Observatory images by Jesse Allen and Robert Simmon, using data from the Level 1 and Atmospheres Active Distribution System (LAADS), and ocean bathymetry data from the British Oceanographic Data Center’s Global Bathymetric Chart of the Oceans GEBCO_08 Grid, Version 20100927. Caption by Michon Scott, with information from Walt Meier, National Snow and Ice Data Center.

Instrument: 

Terra - MODIS - NASA

Photos: 25 cars destroyed in Woodmead fire.

Werner Vermaak ER24 - More photos of #woodmead fire. Courtesy @emmavspgp

25 cars destroyed in Woodmead fire

Johannesburg - A fire that destroyed around 25 cars in Woodmead on Friday was extinguished by 2pm, emergency services said.

“The fire is completely out and the exact cause of the fire is unknown at this stage,” Johannesburg emergency services spokeswoman Nana Radebe said.

“There are a lot of stories including that the fire was caused by two children playing with fireworks and the grass caught fire. At this stage it can't be confirmed and we will investigate the incident.”

She said people at the scene had alleged that children were playing with fireworks on the grass parking area and the grass caught fire and “quickly spread” to the vehicles.

ER24 spokesman Werner Vermaak said there were no injuries.

“Paramedics and rescue personnel are on the scene. No injuries have been reported and I can confirm that the fire is out. The cars were parked on a grass parking,” he said.

Vermaak said they first received a call about the fire at 11.45am.

Most of the cars belonged to Muslim men who had gathered at Mia's Farm for a weekend of spiritual rejuvenation.

The event had been arranged by the Waterval Islamic Institute.

Police could not immediately comment.

- Sapa/IOL

Johannesburg highway flooded

Johannesburg - Motorists should avoid the double-decker M1 south at Newtown because the highway was flooded by rain late on Friday afternoon, Johannesburg metro police said.

Chief Supt Wayne Minnaar said that only one lane of the freeway was open to traffic and that there was congestion due to heavy traffic volumes.

"Motorists can use the M2 or the N1 as alternatives," he said.

- SAPA/News24

SA National Severe Weather Warnings: 29 March 2013 16h00 SAST

• Current warning: Eastern Cape
• Updated: 29/03/2013 15:42:05
• Validity: 2013-03-29 to 2013-03-30
• Type: Watch. Be prepared
• Subject: Heavy rain, heavy swell
• Detail: WARNING: 1. Heavy swell in excess of 4m is expected between plettenberg Bay and Port Alfred. WATCH: 2. heavy rain is possible in places over the central parts tonight spreading to the east from tomorrow.

• Current warning: Kwazulu Natal
• Updated: 29/03/2013 15:42:05
• Validity: 2013-03-30 to 2013-03-30
• Type: Watch. Be prepared
• Subject: Heavy rain in the extreme south
• Detail: 1. Heavy rain is possible in places over the extreme southern parts.

• Current warning: Northern Cape
• Updated: 29/03/2013 15:42:05
• Validity: 2013-03-29 to 2013-03-29
• Type: Watch. Be prepared
• Subject: Heavy rain in the south-east
• Detail: 1. 3. Heavy rain is possible in places over the south-eastern parts.

• Current warning: Western Cape
• Updated: 29/03/2013 15:42:31
• Validity: 2013-03-29 to 2013-04-01
• Type: Warning. Take action
• Subject: Heavy swell, gale force winds and heavy rain (from Sunday)
• Detail: WARNINGS: 1. Heavy swell in excess of 4m is expected between Lambert's Bay and Plettenberg Bay. 2. A gale force SE wind of 65 to 70 km/h is expected between Cape Point and Cape Agulhas. ADVISORY: 3. Heavy rain is possible in places except in the south-east, from Sunday evening into Monday

• Current warning:  All other Provinces
• Updated: 29/03/2013 15:42:05
• Validity: 2013-03-29 to 2013-03-30
• No warnings nor advisories in effect
• Subject: No Alerts
• Detail: No Alerts.

- SAWS

SA Weather Satellite Image: 28 March 2013 19h00 SAST

- Eumetsat (Click on image for larger view.)

Oudtshoorn: Storm rig skade aan, slaan krag af

OUDTSHOORN NUUS - 'n Hewige donderstorm met swaar reën en gepaardgaande sterk wind het Dinsdagaand boomtakke afgeruk en 'n paar KKNK-tente platgevee.

Die storm het dele van Oudtshoorn vir etlike ure sonder krag gelaat.

Plase in die Rooiheuwel-omgewing was Woensdagoggend teen 07:00 steeds sonder krag. Weerlig het twee palmbome in Steynstraat aan die brand geslaan terwyl lede van 'n produksiespan by die Johnny Biskit-saal moes bontstaan om te keer dat hulle toerusting beskadig word.

Die swaar reën wat slegs 'n paar minute geduur het, het water deur die saal laat stroom.

By die Rivierbuurt waar uitstaltente reeds opgeslaan is het die wind van die tente platgewaai, maar sover vasgestel kon word is geen ernstige skade aangerig nie.

- Oudtshoorn Courant

SA National Severe Weather Warnings: 29 March 2013 04h00 SAST

• Current warning: Eastern Cape
• Updated: 28/03/2013 15:36:19
• Validity: 2013-03-28 to 2013-03-30
• Type: Watch. Be prepared
• Subject: Sever Thunderstorms over the western interior, heavy rain in the east, heavy swells
• Detail: TONIGHT: WATCH: 1. Severe thunderstorms are possible over the western interior. TOMORROW: WATCH: 1. Heavy rain is possible in places over the central and eastern parts from the evening into Saturday. ADVISORY: 2. Heavy swell in excess of 4m is expected between Plettenberg Bay and Cape St Francis from Friday night, spreading to Port St. John by Saturday morning.

• Current warning: Western Cape
• Updated: 28/03/2013 15:34:55
• Validity: 2013-03-29 to 2013-03-30
• Type: Advisory. Be aware
• Subject: Heavy swell
• Detail: 1. Heavy swell in excess of 4m is expected between Lambert's Bay and Plettenberg Bay from Friday night.

• Current warning: All other Provinces
• Updated: 28/03/2013 15:34:55
• Validity: 2013-03-28 to 2013-03-28
• No warnings nor advisories in effect
• Subject: No Alerts
• Detail: No Alerts

- SAWS

SA Weather Satellite Image: 29 March 2013 06h00 SAST

- Eumetsat (Click on images for larger view.)

Possible 24 Hour Rainfall: South Africa

- 1stweather.com

GFS Medium Range Forecasts of Vertical Velocity and Precipitation: South Africa

- U.S. National Center for Environmental Prediction (NCEP)