General November Weather

[03Stormchaser]

I see MS have updated tomorrow to a coastal low risk

Capture.PNG

There is also a low risk of thunderstorms with hail about coastal parts of North Otago and Canterbury up to Banks Peninsula during the afternoon and early evening as a weakening trough crosses the area.

http://www.metservice.com/warnings/thunderstorm-outlook

[RWood]

I was in Temuka and Geraldine on Thursday 24th, much more drizzle sweeping through that area than may have been indicated on rain-radar that day.
Almost always looks lush and green in Geraldine through summer.
Blusterous winds here in Ashburton at times today.

There are many South Canterbury stations where the long term rainfall averages for Jun-Aug (driest 3 months) are only about 65%-72% of the Dec-Feb averages. For the 1981-2010 means, at Orari Gorge this ratio is only 56%.

[Richard]

The spill over showers have spread out far enough east to give 14mm here, where Culverden has had only 2mm, Waiau 1.6mm over the last 36 hours.

[spwill]

http://www.bom.gov.au/products/IDQ60801 ... 4569.shtml

Looking at the observations, the 34C only occurred because the flow was offshore (i.e. dry and not humid, with a dewpoint of 12C when the 34C max occurred) for a time in the morning. Once the onshore breeze developed, temperatures dropped as humidity rose.
Outside of equatorial and near-equatorial regions, there are very few places where it can be both 34C and humid (meaning dewpoints in the high 20s for a drybulb like that) at the same time. Cities near the Persian Gulf, Gulf of Mexico, Red Sea, parts of India - certainly subtropical Queensland is not globally notable enough to get onto that list.

I'm only pointing this out because I think we should stop people when they make mad claims like "40C with 95% humidity!!!" which you hear every summer from people in Australia. It is of course nonsense, because if 95% humidity occurred on the Australian east coast, it would be first thing in the morning when temperatures would be around the high teens. 40C and 95% humidity would never occur at the same time, given that the highest ever dewpoint recorded in the world was 35C (in Saudi Arabia).

My location was Noosa, Tewantin which is close to Noosa on the Noosa River had a max of 34.5C, dewpoint 18.1C
Inland at Gympie the max was 38.8C, dewpoint only 5.4C.

[Orion]

Tragic news from the Kaipara Harbour yesterday:

http://www.nzherald.co.nz/nz/news/artic ... d=11755733

can anyone comment on yesterday's conditions in the Manukau Harbour/Heads or the Hauraki Gulf?

[Manukau heads obs]

I can't understand how an experienced skipper got into trouble on the Kaipara bar yesterday
there was a forecasted large swell on the west coast yesterday...but that did not turn up untill lunch time..
and the wind was relatively light in the morning..so if the vessel crossed the bar in the morning in what would have been good conditions then tried to return as the swell increased (and the wind did increase slowly during the day..and a weak front did cross the auckland area around 4pm which increased the wind more..but it had been reporting missing before that)..then sometimes the west coast swell can increase very quickly...in this case it sounds like it doubled in size , going by the Piha surd report, quickly...I have seen this happen myself....and this could have caught them out

[Orion]

A few bubbly clouds have popped up to the south-east of here.

[mikestormchaser]

Things going up coastal Canterbury atm. Offshore though

[03Stormchaser]

Yeah looks like its sticking very coastal

[NZ Thunderstorm Soc]

Low level CB forms to the south of here going from the west to east. Could be something in them as the were a few crackles on the radio on the truck as I was driving home, about 2:45pm to 3pm.
A few rain shafts from them possibly with hail.
Took some photos on my phone but I can't find the cable to put them up on here. It's probably down in Geraldine.

[Chris W]

Drove out to Birdlings Flat and just watched the storm now over the Peninsula pass overhead, a few IC strikes and very loud thunder. Now back in Spreydon and looking at a very dark approaching cloud to the SW.

This was all after watching this pass east of the peninsula:

IMG_0034.JPG

[NZ Thunderstorm Soc]

Nice one. Yes, they looked like the ones I saw.
More lager Cb clouds now just to the south of here now.

[Powermad]

I'm watching your first one off the coast of Pegasus Bay. Looks thundery but no lightning.

[Orion]

Beaut photo, Chris W

[mikestormchaser]

Low topped CBs today. Pretty average set up in the end. Nothing worth chasing. Nice photo Chris!!

[NZ Thunderstorm Soc]

You were right with your initial forecast for thunderstorms today plus what Steve Williams from Auckland said from early analysis from the current weather set up patterns.
I recorded a low of 14% humidity as the persistent westerly continued until the abrupt shut-off around 7pm, when a light southerly came in and the thundery cloud sort of dissipated as it moved further east.
It would be interesting to see where the hail fell or any substantial rain fell from today's clouds.

[Thunder]

Great photo there Chris!

[spwill]

The GFS has been showing a trend for increasing dewpoint temperatures later this week and into next week, the arrival of Summer.

[jamie]

The GFS has been showing a trend for increasing dewpoint temperatures later this week and into next week, the arrival of Summer.

That will be good. I am dead sick of this wind

[spwill]

The GFS has been showing a trend for increasing dewpoint temperatures later this week and into next week, the arrival of Summer.

That will be good. I am dead sick of this wind

Light winds here today, week ahead for Ak/ Waikato not looking windy, sea breezes in the mix as well.

[tunster]

http://www.bom.gov.au/products/IDQ60801 ... 4569.shtml

Looking at the observations, the 34C only occurred because the flow was offshore (i.e. dry and not humid, with a dewpoint of 12C when the 34C max occurred) for a time in the morning. Once the onshore breeze developed, temperatures dropped as humidity rose.
Outside of equatorial and near-equatorial regions, there are very few places where it can be both 34C and humid (meaning dewpoints in the high 20s for a drybulb like that) at the same time. Cities near the Persian Gulf, Gulf of Mexico, Red Sea, parts of India - certainly subtropical Queensland is not globally notable enough to get onto that list.

I'm only pointing this out because I think we should stop people when they make mad claims like "40C with 95% humidity!!!" which you hear every summer from people in Australia. It is of course nonsense, because if 95% humidity occurred on the Australian east coast, it would be first thing in the morning when temperatures would be around the high teens. 40C and 95% humidity would never occur at the same time, given that the highest ever dewpoint recorded in the world was 35C (in Saudi Arabia).

34.4C with a dewpoint of 12.1C does feel humid. You could also say 12C dewpoint is not dry air but all these things are relative. My comment about humidity was more about the day, general Dps 19C-20C.
21C dewpoint here this morning with towering clouds around, some downpours for the Sunshine Coast today

If we call 34/12 humid then it doesn't leave many other words to describe conditions like 34/26 like they get routinely in equatorial regions.
I also thought that Queenslanders wouldn't find 19C or 20C dewpoints particularly humid.

[tunster]

http://www.bom.gov.au/products/IDQ60801 ... 4569.shtml

Looking at the observations, the 34C only occurred because the flow was offshore (i.e. dry and not humid, with a dewpoint of 12C when the 34C max occurred) for a time in the morning. Once the onshore breeze developed, temperatures dropped as humidity rose.
Outside of equatorial and near-equatorial regions, there are very few places where it can be both 34C and humid (meaning dewpoints in the high 20s for a drybulb like that) at the same time. Cities near the Persian Gulf, Gulf of Mexico, Red Sea, parts of India - certainly subtropical Queensland is not globally notable enough to get onto that list.

I'm only pointing this out because I think we should stop people when they make mad claims like "40C with 95% humidity!!!" which you hear every summer from people in Australia. It is of course nonsense, because if 95% humidity occurred on the Australian east coast, it would be first thing in the morning when temperatures would be around the high teens. 40C and 95% humidity would never occur at the same time, given that the highest ever dewpoint recorded in the world was 35C (in Saudi Arabia).

My location was Noosa, Tewantin which is close to Noosa on the Noosa River had a max of 34.5C, dewpoint 18.1C
Inland at Gympie the max was 38.8C, dewpoint only 5.4C.

Definitely for us temperate beings, a combination of high teen dewpoints and mid thirties dry bulb would feel uncomfortable (tropical and subtropical beings might not think much of it though). It's probably a good demonstration of how the dewpoint depression (from which RH would be derived) doesn't tell us enough information. In the UAE they routinely get days where it's 40/22 (ish), and that large dewpoint depression does not prevent it from feeling "not humid".
It's kind of a shame that RH is the only commonly used measure of "humidity" (really moistness/discomfort would be a better term) when people themselves don't really understand the "relative" aspect of it. It would be easier to communicate if dewpoints and wetbulbs were more commonly understood.

[Manukau heads obs]

yes, agree...relative humidity is relative...as the temperature goes up, it goes down (for the same dew point)
dewpoint is a much better..it gives a good indication of where the air mass has come from

[NZstorm]

An uneventful November for Auckland.

Ricky's weather station showing Grey Lynn average max 21C Min 12C. Precip 70mm.

[Manukau heads obs]

yeah, pretty boring...
especially this anticyclonic gloom currently !