Event Discussion on Sydney's Historic Hailstorm Events

Joshua Randazzo

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I'm sure at least some of you are aware of the major hailstorm that hit Sydney on new years day 1947 when a classic supercell tracked in a line from liverpool to the eastern suburbs of the city before dissipating out at sea east of bondi, this storm produced hail larger then 8cm according to newmans BOM report of the storm.

The storm was first spotted at 10:00am over the blue mountains with the bom noting how the storm was developing very different from other storms with the underpart of the cloud being mottled and serrated rather then mammilated and look angry black, while false cirrus tuffs were discernible at the top.

The storm cell intensified as it got closer to the coast with it having a very peculiar formation east of liverpool according to newmans report of the storm,hail the size of billiard balls fell over the south western suburbs before unleashing it's full power over the CBD and the eastern suburbs with hail the size of oranges reported over the eastern beachers with a ww2 veteran who was sunbathing at Bondi Beach stateing "though [he] was back in the firing line overseas".

People who were at sydney eastern beaches were subjected to the 8cm+ hail without any selter.

Now time for details about how this storm formed into a supercell. on the day the max temp recorded was 32.7 and humidity reaching 73% as well as a north east sea breeze.
here is a link of newmans report of the storm:https://en.wikisource.org/wiki/Phenomenal_Hailstorm_with_Thunderstorm,_Sydney_1st_January_1947

As can be read the sea breeze caused it to form into supercell as well at very little capping inversion.

1947_Sydney_hailstorm_boat.jpg

very large hail falling into water from classic supercell at rose bay in sydney's eastern suburbs.

87889477_2588946641387438_7806618877462315008_n.jpg

Photo of giant hail that fell at bondi beach. looks like some 10cm stones there!

118214041_1026238921142261_8996354542066066512_n.jpg

classic supercell structure as the storm moved out to sea.
 
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Joshua Randazzo

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This thread will be me just talking about my thoughts on the great Sydney hailstorm of 1947.

As i have said many times the 1947 Sydney hailstorm was strongest to the east of the CBD of Sydney where hail larger than 8 cm was recorded . That means imo that topography had very little to no effect on intensifying the storm.

1947 sydney hailstorm mapp.png

As can be seen on this very poorly made track map of the storm i made the storm formed into a supercell just east of liverpool, now this where the 1947 hailstorm was very unusual only very few classic storms (storms that form due to a trough) make it to the coastline at full strength let alone at its strongest strength this means that some weather pattern on new years day 1947 increased the strength of storm as it got closer to the coastline. On new years day 1947 the max temp recorded at the CBD was around 30 degrees and humidity reaching 73% plus a north east sea breeze. some people on this forum think that the sea breeze kill storms while this is true a lot of the time on occasions the sea breeze can increase lift, why this happens is beyond my ability to understand but i think it has something to do with increasing turn in the thunderstorm in very isolated cases.

Other photos of the supercell:

1947_Sydney_hailstorm_boat.jpg

As can be seen on this photo taken by Bob Rice Rose bay was hit very hard by the supercell however the hail that fell as rose bay was not the largest that fell with the largest hail falling south of rose bay around the bondi area with many reports of 10 cm hail with official reports being 8 cm.
120108930_654792971861048_1295541763689665460_n.jpg

This was the size of the hail that fell at Bondi, looks like some 10cm ones there!

897395713-hailstone-hail-precipitation-rooftile-windowpane.jpg

This is a view of the side of the supercell as it moved off to sea and dissipated east of bondi. very classic supercell structure there!

If anyone more educated than me on weather has an idea on how the 1947 sydney supercell was strongest on the coast fell free to comment below.

also sorry about the poor punctuation i'm not the smartest of people when to comes to typing.

https://en.wikisource.org/wiki/Phenomenal_Hailstorm_with_Thunderstorm,_Sydney_1st_January_1947
 
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Joshua Randazzo

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Id rate the 1947 sydney hailstorm about the same as the 1999 storm in terms of unusualness. but in terms of structure the 1947 sydney supercell is better looking as was evident even before it formed into a supercell as was told in the report of the 1947 storm " Mr R.R.C. Porter, Observer at Mascot, saw the cloud which gave rise to the storm forming at approximately 1000K between approximately Fairfield and Liverpool. It had then reached a fairly advanced stage of development with a peculiar formation".

PECULIAR FORMATION is words you don't here the BOM use very often. yes the 1999 storm had very mean looking formations but in terms of supercell formation its not a mean looking as the 1947 supercell...

vlcsnap-2021-05-23-02h51m54s975.png
 

Snowmaker7

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Id rate the 1947 sydney hailstorm about the same as the 1999 storm in terms of unusualness. but in terms of structure the 1947 sydney supercell is better looking as was evident even before it formed into a supercell as was told in the report of the 1947 storm " Mr R.R.C. Porter, Observer at Mascot, saw the cloud which gave rise to the storm forming at approximately 1000K between approximately Fairfield and Liverpool. It had then reached a fairly advanced stage of development with a peculiar formation".

PECULIAR FORMATION is words you don't here the BOM use very often. yes the 1999 storm had very mean looking formations but in terms of supercell formation its not a mean looking as the 1947 supercell...

vlcsnap-2021-05-23-02h51m54s975.png
I'd say they were both just as unusual in terms of the size of the hail, BUT the Sydney 1999 storm was far far more out of the ordinary in terms of the trajectory of it. I don't know a lot about the 1947 storm myself, but I remember that on the morning before the 1999 storm, the BOM had forecasted something like "possible shower along the coast" - and look what happened. We have not seen a storm since then follow the coastline from south to north, and certainly not a storm of similar severity since.
 
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Billy Bob

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The supercell which spawned the Kurnell tornado in 2015 similarly tracked along the coast, though covered a lot less ground than the 1999 hailstorm. Michael Thompson (ozthunder) has a video of the 1999 storm as it developed over Shellharbour on his YouTube channel. Apparently he then phoned the Bureau, warning them of the potential for large hail, but was pretty much ignored!
 
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Ultra 2.0

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I was living at Paddington when the 99 storm hit. fortunately our terrace had a corrugated iron roof. soon looked like a golf ball. it was the tiles falling off the roof along the street that did the most damage to cars park out front.
 
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Joshua Randazzo

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I'd say they were both just as unusual in terms of the size of the hail, BUT the Sydney 1999 storm was far far more out of the ordinary in terms of the trajectory of it. I don't know a lot about the 1947 storm myself, but I remember that on the morning before the 1999 storm, the BOM had forecasted something like "possible shower along the coast" - and look what happened. We have not seen a storm since then follow the coastline from south to north, and certainly not a storm of similar severity since.
i agree but that does not mean that the 1947 supercell was not unusual in the way it moved,it formed over the blue mountains which is not unusual but the way it turned into a supercell just east of Liverpool which it very flat and on most days weaken storms. why didn't it weaken when it slid off the mountains? what happened just east of liverpool? it was too far inland for the sea breeze to have any effect and in most cases the sea breeze weakens storms. if it slid right over the top as steve777 said it wouldn't of intensified like it did it would of stayed the same intensity.

hopefully POW_hungry or donzah can explain this to me. as it boggles my mind

 

Joshua Randazzo

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i agree but that does not mean that the 1947 supercell was not unusual in the way it moved,it formed over the blue mountains which is not unusual but the way it turned into a supercell just east of Liverpool which it very flat and on most days weaken storms. why didn't it weaken when it slid off the mountains? what happened just east of liverpool? it was too far inland for the sea breeze to have any effect and in most cases the sea breeze weakens storms. if it slid right over the top as steve777 said it wouldn't of intensified like it did it would of stayed the same intensity.

hopefully POW_hungry or donzah can explain this to me. as it boggles my mind


CDE5M3VUMAA4_CP.jpg
 
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Joshua Randazzo

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My father used to recall this storm quite frequently! On the day, he was playing cricket at Concord. They could see the dark storm clouds and hear the thunder but Concord did not get a drop of rain. He could recall the heat and oppressive humidity of the day, even in his older years. As my father returned home that evening (at that time he lived in Forest Lodge - Glebe, near the city) the damage from the storm became more apparent as he got closer to the city. His mother's home sustained some cracked roof tiles but the worst damage was to the east of the city. This event was clear in my father's mind right up until just before his death.

Regards,

Geoff Thurtell



"the worst damage was to the east of the city"
 

Hermon

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IIRC the 1999 hailstorm had its genesis much closer to the coast than the 1947 event, and it was a much cooler day. I well remember the tarps over nearly every roof Northeast of Sydney airport in May 1999.

The closest I saw to the Sydney hailstorms in Melbourne was near Bayswater and Ferntree Gully in March 2010. Those supercells were fast moving from the Northwest.
 

Joshua Randazzo

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800px-Sydneyhailstorm3.jpg

66 points of rain (23mm) at randwick but only 21 (7mm) at waverley! must of been a overhang over the rose bay area as it reached max intensity on the coast. this supercell was not HP like the 1999 event. possibly a classic supercell.
 

Joshua Randazzo

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this is the graph of the day the 1947 Sydney hailstorm happened. to hard for me to understand. but maybe it looks like classic supercell conditions maybe donza or good old pow hungry can understand this graph


500px-Sydneyhailstorm14.jpg
 
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Joshua Randazzo

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here are all the recounts of the 1947 Sydney hailstorm that i can find on Facebook.
"Sky Tuned Green"
"Dirty murky black cloud"
"Big as cricket balls Belmore"
"The storm came in quite suddenly"


hailstorm 2.pnghailstorm 3.pnghailstorm 4.pngsydney hailstorm 1.png
 

Joshua Randazzo

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More rambling:

Since 1900 four supercells have hit Sydney's CBD and east here is the list:
  • New years day 1947
  • April 1999
  • December 2015
  • December 2018
I know i will trigger some people when i say this but i'd rate the 1947 sydney supercell event the most unusual followed very closely behind by the 1999 event.

That 1947 event was a freak of nature, how could a storm on flat topography actually intensify into a strong classic supercell? What happened just east of liverpool that day most of been a one in 1000 chance of happening and for it to drop the largest hail (8-11cm) on the eastern beachers? 1 in 1000 chance.
 

POW Hungry

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this is the graph of the day the 1947 Sydney hailstorm happened. to hard for me to understand. but maybe it looks like classic supercell conditions maybe donza or good old pow hungry can understand this graph


500px-Sydneyhailstorm14.jpg
It’s got that lean to it forsure.
Little heat cap at 8,000 feet, but easy to breach with some good surface temps.

If I am reading that 9am obs right, then yeah, explosive growth is the only outcome with max temps 6 hours away… would like to see the winds though.
 
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POW Hungry

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That North Bondi image, whilst inconclusive, doesn't offer an indication of the sea-breeze (onshore white caps) at that point of time - unless of course the SB was on the Southern flank.
 

Joshua Randazzo

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so what i take from all this is that the conditions on the day were average for a storm to develop. so why did that storm cell intensify into a supercell just east of liverpool? how could it be strongest on the coast when the conditions were not favorable for supercell development?
And the max temp where the storm was strongest was only 26!
 

Joshua Randazzo

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Here's Dick Whitaker's blog about the 1947 sydney hailstorm supercell:​

The Great Sydney Hailstorm of 1947​


New Years Day 1947 looked to be like a typical Sydney summer day - hot and humid but with conditions moderated a little on the coast by the very welcome afternoon north-east sea breezes so eagerly anticipated by the locals.

Afternoon thunderstorms are not unusual for Sydney around this time of the year, and they usually begin with an increase in cloud - a type of formation called “cumulus” - over the Blue Mountains to the west of the city. Sometimes these will eventually develop into full-blown storms, which then move across the Sydney basin around mid to late afternoon.

So when cloud began to increase from the west during the late morning, it all appeared as if afternoon thunderstorms were again “on the cards”. However, there was something different in the way this storm was developing.

The Bureau of Meteorology was at that time located at Observatory Hill, which is near the south-west pylon of the Sydney Harbour Bridge. The official Bureau report noted:

“The first definite indication of cloud development at Sydney occurred towards 1300 (1pm) when cumulus commenced to build in the west and south-west. By about 1400 (2pm) this covered the south-west quadrant of the sky and appeared to be moving east, but keeping south of the city. The underpart of the cloud was mottled and serrated or curtained, rather than mammilated, and looked angrily black, while false cirrus tufts were discernible at the top”.

The cloud continued to increase across the city and become more and more menacing
. The Bureau report continued -

Shortly before the rain commenced at the Weather Bureau, shallow cumulus was observed moving from the north-east below the main cloud structure, which was coming from the westward, and between this and the overlying cloud, considerable turbulence was apparent. At this time there was a terrific noise which appeared to come from the Harbour Bridge as though several trains were passing over. It was definitely not the sound of hail or rain to the south, and it is reasonable to assume its origin was in the cloud”.

However, unknown to the Bureau at this stage, the storm had already blasted a trail of wreckage across south-western Sydney, tracking on a line from Liverpool to the southern parts of the CBD. Billiard ball sized hail sliced through rooftops, battered cars and injured pedestrians.

Path.jpg

Left: The track of the storm across the Sydney Basin
(Click on image to enlarge)


However the full fury of the storm finally broke as it crossed the eastern suburbs, with huge hail falling through Surry Hills and the Rose Bay – Bondi area. Because of the hot temperatures, as well as the fact it was a public holiday, large crowds were swimming and sunbaking on Bondi Beach, and many injuries resulted as these unprotected people were caught in the open and pelted with hail as large as oranges.

Hail47.jpg
Left: Plaster casts of the hailstones taken at the time by a dentist at Earlwood shows their massive size. (Click Image to enlarge)

The Sydney Morning Herald quoted Mr. H. Lacey, a returned soldier who was sunbaking in Bondi Beach at the time. “I thought I was back in the firing line overseas. When the hail began to fall it rattled like machine gun fire. People were lying on the ground and others were bleeding from arms and shoulders”. Fifteen year old Edna Menzies, the niece of the then leader of the Opposition and future Prime Minister, Mr. R.G.Menzies, was knocked unconscious by a hailstone “as large as a cricket ball” whilst swimming at Clovelly. She was rescued and taken to hospital, remaining unconscious as she was loaded into the ambulance.

People waiting for trains on Central Station ran for cover as hail punctured the platform rooves above them and showered them with debris. The skylight running along the entire length of the old indoor area of the station was smashed and “jagged pieces of glass up to four inches square fell among a crowd of about 100 people”.

The clock face above the station was smashed and nearby Crown Street Women’s Hospital received a badly damaged roof, terrifying both staff and women in labour. Some automobiles of the day had canvas (or “soft tops”), and many of these were holed by the hail, injuring the drivers and passengers within. Windows of trams operating across the eastern suburbs were shattered by the ice, showering passengers with broken glass.

SMH.jpg

Left: The front page of the Sydney Morning Herald,
January 2nd 1947. (Click image to enlarge)


The Sydney Morning Herald led with the story on Page 1 the next day, under the banner headline “Ice Storm Lashes City and Suburbs” and recounted a long list of the injuries and damage. Some 350 people were treated by ambulance men and hospitals as a result of hailstone impact and flying debris, particularly glass from broken windows. “For nearly three hours, ambulance wagons travelled backwards and forwards from eastern suburbs beaches with the injured” the Herald reported. Other victims were “picked up in doorways bleeding from head wounds caused by the lumps of ice and by flying glass from hundreds of broken windows”.

Fantastic scenes occurred at the Rose Bay Flying Boat Base as hail smashed the hangar roof to pieces and turned the surrounding ocean into a Pearl Harbour of churning white water. By coincidence, Bob Rice, a Sydney Sun photographer was on location and took an amazing photograph, showing the extent to which the ocean was churned up with hail, producing a dense sheet of splashes as far as the eye can see.

Rosebay.jpg


Large hail mashing down across the Rose Bay Flying Base, January 1st 1947. (Click image to enlarge)

Finally passing across the coast and moving out to sea, the storm left behind it a devastated city, with widespread structural damage, many personal injuries and mounds of ice that remained intact for many hours after. Numerous trees, including large swathes of Centennial Park were stripped of their leaves, producing a dank smell of rotting vegetation across the city.

Interviewed the next day, the acting State Meteorologist, Mr Newman, said “The approach of such a storm could not be forecast accurately, but it is possible that because similar conditions are expected to prevail today, that a repetition, not quite so severe, can be expected”. Happily, this second storm did not eventuate.

Sydney was staggered by the enormity of the incident, as there had not been even a remotely similar storm in living memory. Hundreds of houses had severely damaged roofs and because it was only some 18 months following the end of World War 2, there was a severe shortage of building materials. This meant that some roofs were to be left covered by tarpaulins for several years after. This, in turn, resulted in a steadily rising damage bill, as these roofs leaked whenever the tarpaulins were dislodged by strong winds and rain.

Weather forecasting in those days was severely hampered by the lack of radar imagery and satellite photography now available to the modern day weather forecasting team, and rapidly developing systems, such as thunderstorms, were difficult to deal with.

Also, the ways of distributing weather warnings were very limited and for “short term” events, such as those involved with an approaching thunderstorm, radio was the only way.

However, this was the era before portable and car radios were generally available, and this meant for those not at home, weather warnings were not easily accessible. This is a far cry from today’s situation where information is distributed through portable radios, mobile phones and SMS messages. With new technologies, involving the next generation of mobile phones, it is now possible to view current radar images surrounding all the capital cities on a mobile phone screen, and this means that the general population is now far better informed.

As far as the Bureau of Meteorology is concerned, weather forecasters now have available “state of the art”, regularly updated radar and satellite photography, and this enables accurate identification and tracking of thunderstorms to be undertaken and warnings issued - before a metropolitan area is threatened.

It was widely believed that the New Years Day storm of 1947 was a freak event, unlikely to ever happen again, but just over 52 years later, history repeated itself. Against all the odds another similar storm devastated eastern Sydney in 1999.

Reference: Australia's Natural Disasters, Richard Whitaker, New Holland Publishing
ISBN 1877069043
 

Joshua Randazzo

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just imagine what is was like for the people on Sydney's eastern beaches that afternoon. 26 degree day 73% humidly sea breeze very good beach weather so lots of people on the beach then dark green cloud barrel's in from south west and brings hail larger then 8cm.
1947 map.jpg

This map that i made shows how there was most likely a overhang north of bondi as very little rain was recorded in that area and in the core of the storm randwick recorded 23mm of rain causing minor flooding.

and i must say the sea breeze this time didn't weaken the storm nor did the storm "slide right over the top" in newmans report of the storm it states that additional energy was generated by the sea breeze.
 

Joshua Randazzo

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Forum post i found:


David,

In the presentation by Dick Whitaker on Wednesday night, there obviously was no mention of the type of supercell mentioned. I am surprised that the word "super-cell" was used in the first place given the term was founded in the 1950's - obviously it was suggested after the event. Whether it was a classic or HP is unknown - very heavy rainfall and flash flooding as well as internal water damage in houses also occurred in some suburbs. This tends to dispell the hypothesis of an LP supercell. If the storm organised rapidly with a new updraft, one should not be surprised of a huge overhang dropping massive chunks of hail in some areas with little or no rainfall.

The question begs: was this hailstorm potentially more damaging than the Sydney hailstorm April 14 1999? Given the observations of hail size, I see no real evidence of one being more intense than the other. It goes down to the fact that 1947 had a sparse population and thus not as much observations into the database. However
, I recall Rob Webb suggesting there were so many reports of hail 10 to 11cm, that they accepted that as a new maxmimum hail size.

Regards,

Jimmy Deguara
 

Joshua Randazzo

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Developing from the Blue Mountains to the south-west of Sydney in the morning of 1 January 1947, the storm cell was first identified at 10:00 am by weather observers at Mascot.[7] The formation of storms in this region is not unusual, especially given the hot and humid conditions at ground level which causes atmospheric instability. However, the Bureau of Meteorology reported that the formation of the storm was different from most others, describing how "the underpart of the cloud was mottled and serrated or curtained, rather than mammilated, and looked angry black, while false cirrus tufts were discernible at the top".[1][2]

The storm cell dropped hailstones the size of billiard balls across the south-western suburbs of Sydney. It moved directly over Liverpool at 2:25 pm, heading in a north-east direction before slowly bending its path and travelling almost due east as it passed over the southern part of the central business district.[7] "Large explosion-like sounds", presumed to be thunder by the Bureau, were heard around the Sydney Harbour Bridge.[13] The sounds were described by the Bureau—who were based at Observatory Hill, next to the southwest pylon of the Bridge, in 1947—as a "terrific noise" akin to "several trains ... passing over [the Bridge]".[2]

The storm intensified as it cut through the suburbs, and eventually unleashed its full power across the eastern suburbs of Sydney. The suburbs most seriously affected were Surry Hills, south of the central district, as well as Bondi and Rose Bay in the Waverley region which were struck at around 2:40 pm.[6][8] The hailstorm pelted beach-goers, particularly at Bondi Beach, and the situation was described by a Second World War veteran as "though [he] was back in the firing line overseas".[13] The hail in the coastal regions was described as being of similar size to a cricket ball.[7]

 

Joshua Randazzo

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Since talking to Karl Lijnders about how the 1947 Sydney hailstorm was strongest on the coast i have come to the conclusion that the reason the 1947 Sydney supercell was strongest on the coast is: big time sea breeze convergence and breaking of the heat cap. with how weak the trough was if there was no sea breeze there would of been no massive hailstorm at least in the east maybe a classic afternoon thunderstorm in the west.
 
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Joshua Randazzo

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That North Bondi image, whilst inconclusive, doesn't offer an indication of the sea-breeze (onshore white caps) at that point of time - unless of course the SB was on the Southern flank.
“Shortly before the rain commenced at the Weather Bureau, shallow cumulus was observed moving from the north-east below the main cloud structure, which was coming from the westward, and between this and the overlying cloud, considerable turbulence was apparent. At this time there was a terrific noise which appeared to come from the Harbour Bridge as though several trains were passing over. It was definitely not the sound of hail or rain to the south, and it is reasonable to assume its origin was in the cloud”.
 

Jac0b

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I think the 1999 one was more unusual. The time of year was probably the most surprising for me, only 2 months from the winter solstice. Mid-April is well out of the usual thunderstorm zone from Oct - Feb. And the daily temperature was only mid 20's with no real instability anywhere.

That hailstorm had insane convection currents to be able to drop tennis ball hail, you'd be lucky to get a hailstorm like that even after a humid 35°C or 40°C in summer.
 

Joshua Randazzo

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I think the 1999 one was more unusual. The time of year was probably the most surprising for me, only 2 months from the winter solstice. Mid-April is well out of the usual thunderstorm zone from Oct - Feb. And the daily temperature was only mid 20's with no real instability anywhere.

That hailstorm had insane convection currents to be able to drop tennis ball hail, you'd be lucky to get a hailstorm like that even after a humid 35°C or 40°C in summer.
i agree but the 1947 storm supercell was still very very unusual in that it formed over the blue mountains and made it not only to the coast but at the coast at its max intensity a result of strong outflow hitting the strong north east sea breeze which in turn increased the rotation in the supercell. the breaking of a heat cap also helped. no classic Sydney storm shield on this day
 
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Joshua Randazzo

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I think the 1999 one was more unusual. The time of year was probably the most surprising for me, only 2 months from the winter solstice. Mid-April is well out of the usual thunderstorm zone from Oct - Feb. And the daily temperature was only mid 20's with no real instability anywhere.

That hailstorm had insane convection currents to be able to drop tennis ball hail, you'd be lucky to get a hailstorm like that even after a humid 35°C or 40°C in summer.

:oops: the only two other photos of the 1947 storm in eastern Sydney top one at randwick and bottom one at Bondi they look about 6-9cm

nla.news-page000027437605-nla.news-article248304259-L3-fff26ae9043efd91a580f3f8917ca160-0001.jpg
nla.news-page000027437605-nla.news-article248304259-L3-fff26ae9043efd91a580f3f8917ca160-0004.jpg
 
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