Thank you for that info Colmait. I did some searching yesterday and found this site called Oscilmet where you can access the last two weeks of Australian Weather Radar. It is a free registration so I signed up and was able to look at the radar from Thursday afternoon for the Rothwell area.

This is a link to the site: http://www.oscilmet.com.au/?page=l.p


These are screenshots of the 128km Mt Stapylton radar images from 31.10.24 4.59pm and 5.04pm that I got from the Oscilmet site.






I don't know if we are not reading the radar properly but the images didn't make us think there would be hail just some rain. As I mentioned previously the hail was only small.



By coincidence I read an interesting article yesterday by Meteorologist Anthony Cornelius that had a section called "Why Did it Hail When The Radar Showed No Precipitation?"

This is what he said in the article:

"The storm briefly weakened as the cooler outflow from the Rear Flank Downdraft (RFD) pushed ahead of it, temporarily cutting off the warm inflow. However, the storm’s inflow quickly fought back (thanks to the deep, gusty, easterly winds in the lower atmosphere), “bringing the storm back to life” and intensifying it across central to eastern Brisbane, where it delivered extensive large to golf-ball-sized hail.

For many, the hail came as a surprise, falling even before rain appeared on radar. This phenomenon, known as “clear-air hail,” can occur in strong storms when hail wraps around or falls ahead of the updraft due to intense winds. Because this hail occurs in the storm’s overhang, it can sometimes be missed by radar, especially if hailstones are sporadic."

He added: "In some cases, the updraft ahead of the storm can stop rain from falling to the ground as the rain is too light to fall through the updraft. This is known as a "Weak Echo Region." However, as hail is heavier than rain, the hail can fall down through the updraft and reach the ground. So even when there is no precipitation showing on the ground, sporadic hailstorms can occur giving the impression that it's "hailing out of thin air." Source: MetCentre"

Link to article: https://www.weatherwatch...bringing-widespread-hail

Edited by user Saturday, 2 November 2024 11:25:25 AM(UTC)  | Reason: Spelling

Hi Aussie Girl, sorry for the late reply. I have had a bit of trouble with the NBN today.

That was a nice summary of the storm on Thursday afternoon that you put together.

The clouds are called Cumulonimbus. They tower upwards with the updrafts and can reach heights of above 50,000 feet. When the updrafts are strong and the atmosphere is cold enough, hail will form. The hail will fall and rise within the cloud and grow in size. With turbulent severe supercells, the hail can be tumbled so violently up and down and sideways and collect more ice with each tumble etc, that it will come out with different shapes and sizes and sometimes with spikes protruding from them. Usually these severe cells will produce larger hail from 2cm to what we call gorilla hail which is tennis ball size and bigger. Some of the biggest recorded have been over 1kg and can fall at speeds of 160km/h.




On the other hand with slow moving and smoother/ weaker updrafts hail will quickly fall. So they can produce pea size hail and if moving slowly, they can form hail drifts were hail can be a few centre meters thick and deeper..





Fortunately for the area you were in the updrafts were a little on the weaker side but the horizontal winds were quite strong hence the hail falling ahead of the storm. We were in a similar situation near Petrie. There was no signs of rain on the radar, but above the house we had mammatus clouds and light rain falling along with thunder. The radar may not be picking up the moisture correctly as this has happened a couple of times lately.



I took a screenshot of the Sounding but I unfortunately cut the wind barbs off when I cropped the photo. But as you can see by the red lines on the left of the sounding, the air was minus 50°C. Unfortunately I can’t show the wind speeds at the different heights. But the mid levels were quite strong on Thursday.

Edited by user Saturday, 2 November 2024 8:15:56 PM(UTC)  | Reason: Added a hail drift photo

A pretty strong heatwave is building for large parts of Queensland, it is expected to be in full swing by Tuesday onwards. Please keep up to date with warnings. There is also possibilities for some storms along the Border and Southern Interior on Tuesday and Wednesday.