Thunderstorms 28/12/2012

[Richard]

Low cloud clearing here now but there is plenty of med/high cloud.
Can see a line of towering Cu over West Auckland.photo

They are a similar looking cloud formation to what's around here

[jamie]

If anyone is looking at this post right now go to metservice and look at the BOP radar. Use the slider back and forth quite fast and you can clearly see two different motions of rain clouds. The heavier stuff is all moving in a general SSW direction while the really light stuff is moving SE with the main cloud sheet.

Could anyone explain the cause behind this?

[mikestormchaser]

Well bugger it! iv got a 24 hour bug but also determind to head up north if it starts fireing " dedication to storms even when having to stop on side of road for a chuck , have you not got ur cell phone with you richard? because if i am up i could also stop by at urs.

[GreggWard]

If anyone is looking at this post right now go to metservice and look at the BOP radar. Use the slider back and forth quite fast and you can clearly see two different motions of rain clouds. The heavier stuff is all moving in a general SSW direction while the really light stuff is moving SE with the main cloud sheet.

Could anyone explain the cause behind this?

I see what you mean Jamie, but sorry I am not sure how to explain it. Could it be that the lighter falls are coming from medium level cloud, whereas the heavier stuff is coming from showers that being steered by the lower level winds?

Still bloody cloudy here and the temperature is not climbing much, at this stage. I think we will struggle to get to the 23C, here, that Steve mentioned earlier, if this cloud does not move out of the way soon.

[Richard]

Nope no cellphone Mike,i'll PM ya my homenumber

Starting to see a bit more development in the last hour,this looking to my SW,temp climbing up now on 25deg

[GreggWard]

Looks a lot better down your way Richard.

[Tornado Tim]

If anyone is looking at this post right now go to metservice and look at the BOP radar. Use the slider back and forth quite fast and you can clearly see two different motions of rain clouds. The heavier stuff is all moving in a general SSW direction while the really light stuff is moving SE with the main cloud sheet.

Could anyone explain the cause behind this?

Since the Radar is a composite reflectivity scan, I suspect it is virga being detected from higher based clouds than the showers that are at the SFC.
The higher level clouds producing the light precip or virga are flowing a different direction than the SFC wind direction, so that outlines shear is evident.
The only way to confirm this, is to look at the different elevation scans from the radar.....

Update: Got it in one Greg

[GreggWard]

If anyone is looking at this post right now go to metservice and look at the BOP radar. Use the slider back and forth quite fast and you can clearly see two different motions of rain clouds. The heavier stuff is all moving in a general SSW direction while the really light stuff is moving SE with the main cloud sheet.

Could anyone explain the cause behind this?

Since the Radar is a composite reflectivity scan, I suspect it is virga being detected from higher based clouds than the showers that are at the SFC.
The higher level clouds producing the light precip or virga are flowing a different direction than the SFC wind direction, so that outlines shear is evident.
The only way to confirm this, is to look at the different elevation scans from the radar.....

Update: Got it in one Greg

Thanks Tim

[jamie]

Thanks guys. My suspicions were correct then.

Drizzle here all day sometimes heavy. No chance of clearling I don't think.

[ricky]

Some nice crisp towering Cu visible here at times through breaks in the cloud..

[GreggWard]

Patches of blue sky now appearing and a little bit of sunshine. Can also see some Altocumulus Castellanus, so the atmosphere does appear quite unstable.

[David]

Some nice crisp towering Cu visible here at times through breaks in the cloud..

SW sea-breeze at the airport now, so there will be convergence somewhere in Auckland. Sun has just come out here - temperature up to 24C, dewpoint 21C

[GreggWard]

Looks like the Waitomo coast is starting to heat up.

[Richard]

My area is now back into moderate again and looking to the north and NW things do looked like the is development coming down from the Nelson area

[Richard]

looking really good to the NW now,i'm certain that there will be a storm here in maybe an hour or so but going by the speed that these clouds are growing at it maybe bit sooner,if you CHCH blokes are going to chase,i would leave NOW.

[Thunder]

We are up here already Richard. Sitting at the turnoff to Waiau for the moment just north of Culverden. Be here for the next 15 min atleast.

Some nice clouds about. May head closer to Waiau but will see what is happening first.

Cheers
Aaron

[snowstormwatcher]

Heavy rain and Thunder here in Nelson.

[03Stormchaser]

First cg if the day spotted!!

[NZ Thunderstorm Soc]

Nothing much here at the headquarters of the NZ Thunderstorm Society but good to know that things are looking good especiallly in and north in Richard's territory

[mikestormchaser]

Good stuff Steve and Aaron for getting out there! unfortunately iv goten worse as the day went on so havent been able to drive, constantly vomiting, so good thing i didnt go.
Looking at radar though some decent heavy showers on track, moving N to E and going off shore.
So guys it may be worth moving into the cheviot area.

Cheers mike

[Richard]

Yes its looking good towards Waiau, well done you Falla's coming up this way too,this is the cloud that the cg came from.

By the way i'm on my way to Waiau too,be there soon,get a eye out for a grey Nissan.

[mikestormchaser]

hmm also must be some instability down south to as theres a thunderstorm that developed or 'has' developed around dunedin area aswel.

[Storm Struck]

Good to hear you guys are out there chasing, i had work today gahh but im off for 9 days now so thats good.
The area is much broader today on the maps than xmas and boxing day so there may well be some activity move down onto the plains and coast near Amberley and Oxford etc this evening.
It looks as though they are drifting South like the other day.

[jamie]

convergence line forming just west of hamilton. hopefully it grows to something nice.

[03Stormchaser]

Caught the waiau storm, drove up to Mt Lyford. watching new buildups now closer to waiau