Last Friday turned into a frightening experience for many residents of Gqeberha and some surrounding areas.
I was typing away in my office, oblivious to what was happening outside, when Mrs Guru called me, announcing that it looked like the world must be coming to an end.
My immediate thought was that she was making a sarcastic announcement that the municipal contractors were cutting the jungle in our local park.
We all know it would be a miracle of note if that happened.
But no — it was ominous dark black clouds that had descended over the area.
Incidentally, she made a similar remark on Sunday, and yes, it was a municipal contractor of sorts, namely a herd of cattle grazing away in the “forest”, albeit minus a supervisor.
As I returned to my office to inspect the satellite imagery I heard a few cracking sounds from the roof of my garage.
It started getting louder and louder and sounded like boulders falling on the roof, but I knew it was hail.
It was quite a worrying experience, even for me who loves extreme weather events.
Imagine being a grocery delivery driver on a motorbike caught in that storm.
Being a resident of the Bay all my life, I know that we don’t often get fully fledged hail and usually get ice pellets or frozen rain that is mistaken for hail during a rare thunderstorm.
Knowing that corrugated iron roofs amplify sound, I was not overly concerned, but when I went outside and saw the size of this fully fledged hail, my first concern was my precious newly installed solar panels.
Off to Professor Google to see what size hail damages solar panels, and much to my relief, solar panels should withstand hail of 25mm diameter, with many being able to withstand up to 44mm, and some even up to 76mm.
Historically, I can find no incident where windows were shattered in the metro, so I think our solar panels are safe.
There were, however, some reports on the outskirts of Gqeberha of vehicles sustaining minor hail damage.
What was unique about this event was that in some parts of the metro the hail did not instantly melt and accumulated in piles that were visible long enough to be photographed.
During all previous events witnessed, the hail melted before I could even think about grabbing a camera.
As to this occurring in autumn and not summer, it is not that unusual.
The last major hail event in our metro also occurred in April, way back in 1993.
Without getting overly technical, this event was caused by the dryline of the leading edge of a cut-off low.
Before anybody jumps off the handle and blames this singular event on climate change or geo-engineering or any other conspiracy theory, you must understand the dynamics of a thunderstorm cloud (cumulonimbus) and hail.
In simple terms, hail forms in cumulonimbus clouds with strong updrafts that suspend the water droplets, which eventually form into hail through their movement up and down inside the cloud as they grow.
The size is determined by the strength of a thunderstorm’s updraft, and the hail falls to the ground when the updraft can no longer sustain the weight of the hailstone.
In areas close to the Drakensburg in the former Transkei, mountain waves further amplify the effects of the updrafts and suspend the hail for longer, causing hailstones of up to almost grapefruit size that have been known to be fatal, especially for livestock in the open.
The worst incident on record occurred in the village of Settlers near Bela-Bela, where, in 1936, 10 workers were killed by massive hailstones while working in an open field and unable to find shelter.
Closer to home, the Boknes-Cannon Rocks area is also susceptible to large damaging hail, and I have in the past had reports of a large part of Boknes’s windows being shattered with hail larger than a golf ball.
As if that was not enough excitement for one weekend, residents of KuGompo City were treated to a fantastic display of lightning on Sunday night, out over the sea.
Residents questioned why they heard no thunder and if it was a thunderstorm that caused this phenomenon.
The same cumulonimbus cloud that produces the hail, produces the lightning and one must realise that these clouds can reach up to 12–20km or more in height, thus making them visible from miles away.
As thunder is typically audible for up to 16-24km and these clouds were more than 100km out to sea, that is the reason why no thunder was heard and residents thought it was such a strange phenomenon.
As to the cause of this event, it is simply the interaction between a cold air mass and the warm Agulhas current off the east coast of SA, which is a key driver of severe convective activity (thunderstorms) in this region.
My late friend Willie Watts always described the line of cumulonimbus cloud that sits over the Agulhas current for prolonged periods at this time of the year as “the brooms are sweeping again”, referring to the cold air moving over the warm current.
This week in history:
2006: Water restrictions are implemented in the Nelson Mandela Bay metro
Dam Levels
36.94% down slightly from previous weeks 37.33%
Impofu slightly down to 37.36%
Weather Safety Tips:
During a hailstorm, seek cover as fast as possible. If in a vehicle, pull off the road where it is safe to do so and wait out the storm.
Now on Facebook, Instagram, and X: @WeatherGuruEC
- Follow The Herald WhatsApp channel today and stay connected to the stories shaping our world.
The Herald
Would you like to comment on this article?
Sign up (it's quick and free) or sign in now.
Please read our Comment Policy before commenting.