MetService Severe Thunderstorm Warnings

[Paul Mallinson]

September I think.

Paul

[spwill]

The warnings will actually extend out to 180 km from each radar

On the one day Thunderstorms develop over Canterbury the Christchurch Radar goes down

[rawdon]

re CHCH radar ..informed info tells me lightning in the area has affected the equipment..

[MoorfNZ]

Getting very very dark overhead now... wind has strengthened from the south.

[MoorfNZ]

Skies clearing

[rawdon]

the time stamp on messages is one hour advanced.!!!

[NZ Thunderstorm Soc]

What's the difference between a Severe thunderstorm warning and an ordinary thunderstorm warning?
Today's Canterbury thunderstorms were just ordinary thunderstorms, nothing severe at all ?

JohnGaul
NZThS

[Paul Mallinson]

What's the difference between a Severe thunderstorm warning and an ordinary thunderstorm warning?
Today's Canterbury thunderstorms were just ordinary thunderstorms, nothing severe at all ?

JohnGaul
NZThS

John, we don't issue 'ordinary' thunderstorm warnings, only severe thunderstorm warnings. There was no formal warning issued today, only the 'Outlook' charts. Criteria for severe storms are: rainfall intensity greater than 24mm/hr, hail over 19mm, wind gusts over 110km/h and sig tornado.

Paul

[NZ Thunderstorm Soc]

What's the difference between a Severe thunderstorm warning and an ordinary thunderstorm warning?
Today's Canterbury thunderstorms were just ordinary thunderstorms, nothing severe at all ?

JohnGaul
NZThS

John, we don't issue 'ordinary' thunderstorm warnings, only severe thunderstorm warnings. There was no formal warning issued today, only the 'Outlook' charts. Criteria for severe storms are: rainfall intensity greater than 24mm/hr, hail over 19mm, wind gusts over 110km/h and sig tornado.

Paul

Oh, OK? I'm getting confused here, I thought the 'Outlook' charts were for potential thunderstorm occurence, not for severity in the actual thunderstorm occuring?
JohnGaul
NZThS

[Paul Mallinson]

Most of the time the charts depict the potential for non-severe thunderstorms, but when we think they may be severe, then we mark these on the charts as well with the expected associated severe weather - such as rainfall rates of 25-40mm/hr or 20-30mm hail etc. Then, as the day progresses and it is getting clearer that severe TS are likely to occur, then a Svr TS Watch is issued. Then if a svr storm is identified on radar, a cell based type of Svr TS warning will be issued.

Paul

[NZstorm]

informed info tells me lightning in the area has affected the equipment..

It was an unlucky strike. Consider the lightning activity the USA plains get and their radars seem to run without a hitch. Do the NZ radars not have lightning protection.

[tgsnoopy]

I would have thought Metservice would have spent a little more and put in a radio link that could survive a lightning strike EPR, using a telecom line (for something which many would consider essential in a storm) to an elevated site is just crazy.

Paul, I suggest someone talks to Exicom down Wellington way about radio linking those radars.

[Paul Mallinson]

informed info tells me lightning in the area has affected the equipment..

It was an unlucky strike. Consider the lightning activity the USA plains get and their radars seem to run without a hitch. Do the NZ radars not have lightning protection.

This is a good point you make. I would assume that they do have lightning protection. I will make some enquiries.

Paul

[Storm Struck]

When will the radar be fixed, i assume they are fixing it today as its still down .

[Andrew Massie]

Back to volunteer reports, why not use Twitter? We could text reports in.. We really should have that for all the stormchasers out there anyway..!