General November Weather

NZstorm · Unread post by **NZstorm** » Sun 22/11/2015 09:06

jamie wrote:How many strikes were recorded last night? There sure was a lot!

Ricky's tracker detected 12000 from midnight to 6am. Would be interesting to see what the Met Service picked up.

spwill · Unread post by **spwill** » Sun 22/11/2015 09:10

A lightning photo from last night. Too much rain, wind and no shelter for much photography.

spwill · Unread post by **spwill** » Sun 22/11/2015 09:20

The Weatherzone satellite pic for early this morning showing the Cbs
Much of the lightning was over the North shore and then South Auckland, a lot of lightning observed last night.

NZstorm · Unread post by **NZstorm** » Sun 22/11/2015 09:50

Just for the record I have taken last night's observed Whenuapai 12Z sounding marked in yellow where the CAPE would have been. The CAPE values would have been fairly decent by the look and the wind fields were huge.

Elevated storms typically anchor on an inversion so I have marked the instability from that point.

dannews · Unread post by **dannews** » Sun 22/11/2015 09:51

What an awesome storm!

KiwiWeather · Unread post by **KiwiWeather** » Sun 22/11/2015 09:56

dannews wrote:What an awesome storm!

It sure was and it kept me awake most of the night. But hey, it was well worth it

Nev · Unread post by **Nev** » Sun 22/11/2015 10:30

MS recorded over 1300 CG's strikes around Auckland last night, and gusts to 104 km/h at Whangaparaoa yesterday evening. 12mm here overnight.

Here's a couple of Blitzortung screen-grabs from earlier this morn…

Blitzortung -Nov 22, 1.45am.png

Blitzortung - Nov 22, 4.00am.png

Tornado Tim · Unread post by **Tornado Tim** » Sun 22/11/2015 11:05

Blitzortung counted 3200 Cloud to Ground Lightning Strikes last night, most were above 16KA. There would have been much more IC Strikes which Metservices network detects.

Here is a Jet/Sat Animation with Lightning overlay of last nights activity:

The Water vapour image makes the resulting Lightning activity much more clear, notice there is warmer drier section post the front, there would been some good warm dryer undercutting which would have exponentially helped the lift.

Nev · Unread post by **Nev** » Sun 22/11/2015 11:40

Well done Tim

My mistake, I always assumed MS's tracker only picked up CG's. Here's a few excerpts of interest...

''Very, very intense' thunderstorm batters Auckland' - Auckland Now (Stuff)

The northern region was hit by more than 10,000 lightning strikes on Saturday night and early Sunday morning, with over 1300 occurring in the Auckland area. The storm also affected the Coromandel, Waikato and Bay of Plenty areas…

The cold front brought strong winds of more than 100kmh. Winds were strongest out west, where the exposed Manukau Heads registered the strongests gusts of 128kmh. The Harbour Bridge registered winds of up to 96kmh overnight.

Many of the MetService's rain monitoring stations were knocked out by the lightning, but Kerr [MetService meteorologist] said Auckland had seen substantial rain as well. Among the most affected areas was Pukekohe, which had 31mm of rain overnight...

jamie · Unread post by **jamie** » Sun 22/11/2015 12:30

Awesome Tim. Shows the 4 storms that clipped cooks Mercury Bay Area nicely. I'm quite tired today from leaping out of bed for each storm.

What was missed by the models on this? Nothing stood out that I saw in the days leading up and met service had a low risk out.

Willoughby · Unread post by **Willoughby** » Sun 22/11/2015 13:55

jamie wrote: What was missed by the models on this? Nothing stood out that I saw in the days leading up and met service had a low risk out.

Well picked up by Steven W and I think the models did well 15 hours out. Very much an elevated convection setup so the Showalter index is used in this respect (raising the parcel from 850mb rather than the surface or lowest 100mb as CAPE or normal Lifted Index does) as these would have shown very small values.

There's a really good explanation on SI here: http://www.theweatherprediction.com/habyhints/301/

NZ Thunderstorm Soc · Sun 22/11/2015 17:15

You lucky buggers(and buggeresses) getting those thunderstorms overnight when down here, when MS originally forecasted thunderstorms for down here during Saturday, despite the keen ENE wind, conditions were quite hopeless.
Looks like I planned the wrong WE to go to Auckland.

+9

03Stormchaser · Unread post by **03Stormchaser** » Sun 22/11/2015 18:09

Have been in Queenstown for the weekend. Witnessed what I presume was lightning flashes in the walk back to the holiday home early this morning.

On another note, Stormchasers had a mention in a BBC article about chasing in USA.
http://www.bbc.com/earth/story/20151117 ... ed-on-film

NZ Thunderstorm Soc · Sun 22/11/2015 21:00

Just thinking

Was there a severe thunderstorm watch for Auckland issued yesterday? I can't remember as I was concentrating on the useless thunderstorm event issued for Canterbury?

Tornado Tim · Unread post by **Tornado Tim** » Sun 22/11/2015 22:41

NZ Thunderstorm Soc wrote:Just thinking
Was there a severe thunderstorm watch for Auckland issued yesterday? I can't remember as I was concentrating on the useless thunderstorm event issued for Canterbury?

Not that I can recall, in any case Im not sure that the event was severe enough to warrant one.

It was just due to the very good upper level dynamics that the Lightning was as strong and frequent as it was. (in some other countries what Auckland and Northland had would have been a standard storm

)

jamie · Unread post by **jamie** » Mon 23/11/2015 07:25

Yea there was nothing severe about it......maybe gusts of you went looking for them. We are just not used to the frequent lightning.

spwill · Unread post by **spwill** » Mon 23/11/2015 08:27

The northerly flow this week will bring humid air down onto northern NZ so max temps in the low to mid twenties will feel warm.

Vertigo · Unread post by **Vertigo** » Mon 23/11/2015 12:33

What a storm indeed! On the level of the one over the Coromandel a few years back, but that was entirely stationary, with good sheer aloft. These were fast movers due to the jet stream. One of the first one passed almost directly over my house, excellent stuff indeed. Was up for most of the night watching the show. For most of it the lightning was every 10 seconds or so, with peak around every 3-4 seconds at times.

On another note, I downloaded the Blitzortung android app for this event, and it didnt seem to be registering many of the strikes. Is this normal? I didnt compare to the website, as was busy watching the storms.

Razor · Unread post by **Razor** » Mon 23/11/2015 15:30

Yes very jealous of the concept of an actual storm, let alone decent rain... most parts around here are now browning off rapidly and joining North Canterbury in a serious moisture deficit prognosis. A long hot week looms looking at the forecast too

NZstorm · Unread post by **NZstorm** » Mon 23/11/2015 23:01

Such storm set ups as the one at the weekend can produce severe hail. Nothing reported but just making the point that elevated storms are not necessarily non severe. I have seen large hail in USA from elevated set ups similar to that one.

jamie · Unread post by **jamie** » Tue 24/11/2015 06:11

We did get rain drops that made me think this could have hail fall soon. Very large sporadic drops of rain and nothing else

NZstorm · Unread post by **NZstorm** » Tue 24/11/2015 07:14

Looking like a warm front coming south later today bringing some humid air into northern areas. Then we get an upper trough coming in later tomorrow across the moisture so a bit of a convective risk there. Will be keeping an eye on tomorrow afternoon and hopefully not too overcast. Looking like 100% chance of precip anyway. Thunder risk 30% at a guess.

spwill · Unread post by **spwill** » Tue 24/11/2015 08:39

Looks like the best of the upper trough comes through in the overnight hrs tomorrow however there does look to be a thunder risk for the upper North Island later tomorrow where heating can occur.

Bradley · Unread post by **Bradley** » Tue 24/11/2015 11:05

The 10 day rainfall outlook for mid and north Canterbury looks diabolical, any gains made in October will be wiped out by this time next week. Fingers crossed that some useful rain happens by mid December or January could be a recipe for disaster...

Razor · Unread post by **Razor** » Tue 24/11/2015 18:13

Bradley wrote:The 10 day rainfall outlook for mid and north Canterbury looks diabolical, any gains made in October will be wiped out by this time next week. Fingers crossed that some useful rain happens by mid December or January could be a recipe for disaster...

Think the gains are gone already...

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