Australian Severe Weather Forum

Just had a weak line move through North Ryde at 12 noon. Did not see lightning / hear thunder although tracker suggests there are plenty of sparks around. Nice upper trough and storms are moving very briskly (H5 winds are ~ 80knots over Sydney at the moment).

Just heard some thunder as i type this!

Decent instability for the Hunter and storms showing much more intense reflectivity.

Nice intense cell heading towards Tocal - by my estimates at around 100km/h

The storms seemed to not remain intense for sufficient periods. There was a line of light rain ahead of the storms and this may have impeded sustained cells. Lightning was bright/hot in cells nearer Newcastle but the intensity decreased. Most action occurred by 2pm.

Regards,

Jimmy Deguara

Sounds like the instability was intiated on the basis of diurnal heating, and mediated when the heating abated. May have also been like the situation in Melbourne yesterday: Such instability that whole layer lifted and you got convection accross all corners, thus removing diurnal forcing, and requiring another form of lifting to intiate, then when moving quickly away from the intiation point disapating.

Hi John,

I had anticipated that storms would be most active during this time and thought actually all the activity would be out to see by say 3pm. It took another hour or two to clear. The most potent activity seems aligned with the passage of a short wave which seemed to attract my interest this morning. Pity it was not negative tilt:)

Regards,

Jimmy Deguara

Hi,

Here are a few pics from the 13th November chase for what it's worth (this season is hopeless):

 


We rushed down to bag the first storm west of Newcastle - 5 minutes and we had to make a dash futher north to make our initial cell. Some hit lightning hammered sround us - I felt unsafe!

Coopernook

  further north from Coopernook

Coolongolook north of Taree

full rainbow near Kew

Storms were moving at an extreme pace being high based and near unidirectional shear.

Regards,

Jimmy Deguara

Some pics from near Lismore then McLeans Ridges. The initial line of activity was high based and rather ordinary with very little lightning.



One cell approached from the west just on dark. Was a lot of CGs that were very skilful at avoiding the camera, before rain finished things.



Fortunately another very active storm passed across to my north from 10pm onwards (border ranges into the Tweed region). It was moving at 100km/h but was very CG active during that time. Rain on the southern side towards my place did obscure the lightning somewhat.













MB

Very nice pictures guys! I have put my video cam back in it's box hehehe -  depression has well and truly set in  . Yes is was a shocker of a positive tilt Jimmy but it beats today's weather.

Hi David,

The main trough would have been positive tilt but the wave that came through was only slightly positive tilted.

Regards,

Jimmy Deguara

Hello all

I saw my first lightning flash of the season as it came through. It looked like a squall line as it passed over Auburn and areas to the south. It was high based. It produced sharp but brief showers and about 2 mm of rain fell at Auburn. I went out afterwards and travelling down Chiswick Road, I noticed alot of leaf litter and small branches lying on the roads which would indicate to me that a brief period of strong downdrafts had occurred in this area.

Interestingly though - David, you mention the speed of one storm at Tocal moving at about 100 km / hour.

At 6.05 am, this whole system was no more than about 60 km wide and was passing through the Albury to Griffith region and was still south of Wagga Wagga.

I kept looking at the radars and was watching it move through NSW. Its speed was phenominal. The system moved some 450 km in the space of 5 hours which is about right what you say. I put the speed of this system at between 80 and 100 km / hour. By 5.30 pm, it was already in the Port Macquarie region.

I have seen frontal systems move this fast but it is rare. This thunderstorm system moved so far over such a short period of time.

David, that storm you mention near Tocal. I watched it form near Singleton on radars. It looked like it was capable of producing big hail in its initial stages and looked like I saw some rotation on radar in its initial phase. I don't know how long it lasted because I had to get back to work but it stood out amongst the rest of the storm cells moving through this region at the time I was looking at it. It looked very interesting.

And I still have not taken a single photo of a cloud using my cameras this season.


Harley








..

Wow Jimmy, did you go for a drive yesterday or what?!

Some pictures from the my chase on the 13th from Wollongong to Ballina.

1. Video still of explosive development near Gosford - these storms were moving so quick I did not dare even pulling over to take a still.



2. Another cell near Hexham, another speed buster - this time I did take a still -




The trip from Buladelah to Maclean featured many high based storms.

3. Just on dusk an explosive updraft taps into better mositure near Yamba. Another video still.



4. Barely 15 mins later after setting up tripod and look how far the cell has moved !!!!!!

Hi Michael,

Very nice pictures - my favourite in particular is the one of that cell near Hexham. We must have passed each other as we were at Rayomnd Terrace and raced down for the one near the Newcastle turnoff thence had no chance in hell of getting back for the one you were on. My reason for moving was to see the reaction with the boundary and it reacted well!

Did you see the reaction with the front as it moved east or was the front a little too far east form this cell?

And yes they were moving very fast! How did it compare with what you observed in Queensland?

Regards,

Jimmy Deguara

Thanks Jimmy, the Hexham cell looked more impressive than the picture suggest, and yes there was some weak rotation. I noticed your Coopernook cell looked quite good. I passed through the area just earlier whilst the bases were still quite high. I hould have lagged a little further back in hindsight.

Queensland was a different story all together. Moisture was not an issue, too much at Maryborough at 6am actually - hard to see structure through the scud flying everywhere. I was parked in a pineapple field when the core of the morning storm hit, the winds gusted to 50knots max, but the damage I saw later just a few kilometres from me suggested stronger winds. Mind you eucalyptus trees do shed branches quite easily. Later in the day I still had trouble finding sunshine, i should have keep going NW until I found the boundary of drier air, instead due to having to be back at 2pm on Thursday I gambled on further development on the NW f;ank of the Brisbane cells - this did not occur, instead a massive tract of SE Queensland was shaded by an anvil from a strom over 200 kms away. This killed convection. 

I spent the whole 3 days passing other chasers !

Don't think we will passing any chasers for at least a week now. This year is so dreadful !

Hi Michael,

Yes the positioning with respect to moisture and boundaries are an impotant consideration - not like we have a very extensive network of observations to work with!

I personally rode off that day based purely on the models for anything 'too' significant given the weak cap creating early development and thence possible interference with other cloud as you mentioned. However I thought the scenario represented a violent squall line. I did not like the low level shear quite honestly and its chance for tornadoes - despite all the excitement. The best turning with respect to lower level shear seemed to be earlier and further north.

In fact I think the concept of having the anvil somehow created a balance for not too many storms coming through as can be the case in Queensland sometimes. It prevented a major squall line being the recipe of the day.

Regards,

Jimmy Deguara