Storm Australian Severe Weather Forum

Severe Weather Discussion => Australian Severe Storms, Weather Events and Storm Chasing => Topic started by: David C on 01 November 2006, 05:43:15 AM

Title: NSW storms, October 31 2006
Post by: David C on 01 November 2006, 05:43:15 AM
Hi guys,

yes, definitely one of the slowest starts to the storm season, and that probably accounts for things being rather quiet around here!

Anyways, there was a pronounced moisture return yesterday evening and last night which was most welcome I must say :) This morning's sounding showed some quite cold mid-level air however the axis of this is now offshore while another more subtle short wave will move through during the afternoon. It is, overall, a marginal system for severe storms however - Tim Marshall's old daying it's May! - well it's almost November and things will happen.

Any thoughts, anyone chasing?
Title: Re: NSW storms, October 31 2006
Post by: David C on 01 November 2006, 07:55:33 AM
The trough is firing up nicely with storms widespread over the hunter, nw slopes and mid-north coast. Dew points have dropped to as low as 9 in the outer west (excluding the 1.3 at Horsely Park), however mesolaps would suggest a decent moisture advection via the NE seabreeze later this arvo. With the cold upper temps loitering and, possibly a hint of a short wave coming through, I think things are looking pretty good for some action during maximum heating around Sydney.
Title: Re: NSW storms, October 31 2006
Post by: Jimmy Deguara on 01 November 2006, 08:42:16 AM
The intention is to head out chasing - but the dry dew points are a worry - not that it is surprising given the terrible start.

Regards,

Jimmy Deguara
Title: Re: NSW storms, October 31 2006
Post by: David C on 01 November 2006, 09:36:28 AM
I just went outside for a quick look and was horrified by the cumulus that were out there. Meanwhile, intense right-moving cell heading towards Williamtown / Newcastle
Title: Re: NSW storms, October 31 2006
Post by: David C on 01 November 2006, 10:12:38 AM
Had to cut and paste this warning...giant hailstones hehe.....well it certainly looked a very intense storm!

Australian Government Bureau of Meteorology
New South Wales
TOP PRIORITY FOR IMMEDIATE BROADCAST

NSW SEVERE THUNDERSTORM WARNING - SYDNEY/NEWCASTLE/WOLLONGONG REGION
for GIANT HAILSTONES, DESTRUCTIVE WIND, VERY HEAVY RAINFALL and FLASH FLOODING
For people in the
Greater Newcastle and parts of the
Maitland/Cessnock areas.

Issued at 3:52 PM Tuesday, 31 October 2006.

At 3:50 PM , Bureau of Meteorology weather radar detected severe thunderstorms near Clarence Town and the area between Raymond Terrace and Karuah. These thunderstorms are moving towards the southeast. Severe thunderstorms are forecast to affect Salt Ash and Swan Bay by 4:20 PM and Mallabula, Anna Bay and Lemon Tree Passage by 4:50 PM .

Very dangerous thunderstorms were located near Raymond Terrace and Wallsend. They are forecast to affect Newcastle City, Charlestown and Williamtown by 4:20 PM and Warners Bay, Redhead and Belmont by 4:50 PM .

Large hailstones, destructive winds, very heavy rainfall and flash flooding are possible.

A more general severe thunderstorm warning is also current for the Mid North Coast and parts of the Northwest Slopes, Northern Tablelands, Hunter and Central Tablelands Forecast Districts.

This warning replaces the previous warning issued at 3:40pm, correcting the times.
The State Emergency Service advises that people should:
* Move your car under cover or away from trees.
* Secure or put away loose items around your house, yard and balcony.
* Keep clear of fallen power lines.
* Keep clear of creeks and storm drains.
* Don't walk, ride your bike or drive through flood water.
* Unplug computers and appliances.
* Avoid using the phone during the storm.
* Stay indoors away from windows, and keep children and pets indoors as well.
* For emergency help in floods and storms, ring your local SES Unit on 13 2500.

The next warning is due to be issued by 4:50 PM.

This warning is also available through TV and Radio broadcasts, the Bureau's website at www.bom.gov.au or call 1300 659 218. The Bureau and State Emergency Service would appreciate this warning being broadcast regularly.
Title: Re: NSW storms, October 31 2006
Post by: Jimmy Deguara on 01 November 2006, 02:57:47 PM
Hi David,

That is interesting - the storm merged along the boundary and exploded I guess.

Regards,

Jimmy Deguara
Title: Re: NSW storms, October 31 2006
Post by: Jeff Brislane on 01 November 2006, 03:28:05 PM
What was also interesting was the cell just before near Cooma. A very nice intense radar echo showed a cell rapidly develop and then split into left and right movers. The left mover must have had golf ball hail as it's core displayed the maximum echo intensity for at least one frame and over a pretty large area as it was no doubt dumping it's load during it's demise.
Title: Re: NSW storms, October 31 2006
Post by: oscar on 01 November 2006, 05:07:38 PM
Hi people,

My first post here.  A lot to learn, I'm still getting used to the lingo, but a great site with a wealth of knowledge. 

Back on topic, that cell over Newcastle looked like a ripper on weatherzone during the day yet I was surprised to see no news coverage.  Perhaps NBN had a story on it.

Anyone know how severe the storm was?
Title: Re: NSW storms, October 31 2006
Post by: Jimmy Deguara on 02 November 2006, 01:39:55 AM
Hi Simon,

Welcome.

Hail to base ball size apparently! Mostly golf ball - it has been mentioned a supercell by the Weather Channel. Nevertheless, the structure was quite impressive! Shows the importance of boundaries.

Regards,

Jimmy Deguara
Title: Re: NSW storms, October 31 2006
Post by: Jimmy Deguara on 02 November 2006, 11:47:54 AM
Would you be sure Supercells? I would say severe storms but I am just wandering how long lived they were? Yesterday was longer lived.

Regards,

Jimmy Deguara
Title: Re: NSW storms, October 31 2006
Post by: Dave Nelson on 02 November 2006, 11:59:44 AM
hi gang,
             yup, got some pix of that major cell (supercell),   even from sydney it looked spectatular,  gosh I thought I was back chasing in the USA for a while  hahaha,   it regularly showed good overshoot and nice rear end updraught

   as an additional note ....  was suprised no one mentioned the good cell that passed over sydney on friday 20 Oct
it dropped a nice load of hail over the inner west ... ryde - to strathfield to lidcombe area    
photo'ed the tail end of this storm on the way back froom Campbelltown.    It had a good looking flat base that occassionally
went quite ragged   and also displayed good updraught at the tail of it

cheers
Dave N
Title: Re: NSW storms, October 31 2006
Post by: Jimmy Deguara on 02 November 2006, 12:03:01 PM
Hi Dave,

Thanks for the information - feel free to mention any storms you have and post pics. I hope the forum is now working far better with imporved stability and features.

Regards,

Jimmy Deguara
Title: Re: NSW storms, October 31 2006
Post by: Meso on 02 November 2006, 03:13:54 PM
The 'destructive winds' and 'very dangerous thunderstorms' lines from the STW sent a chill up my spine and instantly brought me back to Nov 3, 2000.  As the Bureau don't issue tornado warnings, I've seen them insert these lines into their warnings when there are indications of rotation (if doppler is available), or other supercell characteristics on radar (very high high reflectivity tops, prominent overhangs and BWER on RHI scans, long cell life, etc). Combine that with the 'giant hail' attribute, and I was sure that we had the makings of something pretty big.  Late night news in Sydney showed mostly golf ball sized hail (or smaller).

I'll be looking around for the next few days to see if there are any decent photos from in and around Newcastle.

Mal