spwill wrote:Unusually Low dew point temperatures ( 5-11C) over northern NZ with this heavy rain event, but the upper atmosphere is unusually cold.
Yes, Yesterday I saw a few Altocumulus castelanus clouds although fibbrousy in appearance. In the dry sector of a the low with the predominant S to SE flow.
Risk of flooding with that front staying stationary atm, and convection flaring over sea moving inland with the ENE flow, not good with grounds already being saturated......
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spwill wrote:Unusually Low dew point temperatures ( 5-11C) over northern NZ with this heavy rain event, but the upper atmosphere is unusually cold.
With the rain bearing fronts a better measure of moisture is the precipitable water values rather than surface dp. PW values are around 20mm which is reasonable amount of moisture.
have been surpised how cold it was even in the far north with an easterly flow and rain
it was like 8C and rain overnight in the far north
temperatures getting back to more normal now
Manukau heads obs wrote:have been surpised how cold it was even in the far north with an easterly flow and rain
it was like 8C and rain overnight in the far north
temperatures getting back to more normal now
Yes, we usually associate northern lows with sub tropical air mass but not the case with this one, the instability being mostly generated by unusually cold upper level temperatures.
Thought this MS radar rainfall accumulations graphic for the 24 hrs to 3pm today is interesting.
Shows just how much southern parts of Akld missed out, compared to more northern parts.
MetService 24 hr radar rainfall accumulation to 3pm, Aug 10.jpg
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Manukau heads obs wrote:have been surpised how cold it was even in the far north with an easterly flow and rain
it was like 8C and rain overnight in the far north
temperatures getting back to more normal now
I wonder what freezing levels would be like up north today. (presumably still well above any hills and ranges of Northland and Coromandel)
Looking good for a 20cm+ topup at Ruapehu this Saturday down to 1500m. A ridge looks set to briefly move in for Sunday then slips away again on Monday allowing another 10-15cm of snow. Then for the tasty bit, a big fat high building in from the tasman from Tuesday - Friday. Exactly what I had hoped for..
Nice to see the sun again this morn. Total of of 47mm here from this system.
Below are a few more totals for the 48 hrs to 9am this morn from MS and NIWA…
Just having a quick look at other cold periods in Christchurch and surprisingly it looks like the last 10 days (both maximum and minimum combined) is the coldest 10 day period that has ever been recorded in August
since records began in 1954 at the airport, even though the snow never came for Christchurch it has nevertheless been a very unusual event!
Bradley wrote:Just having a quick look at other cold periods in Christchurch and surprisingly it looks like the last 10 days (both maximum and minimum combined) is the coldest 10 day period that has ever been recorded in August
since records began in 1954 at the airport, even though the snow never came for Christchurch it has nevertheless been a very unusual event!
And for the last three days the heavy frosts at the airport have not occurred in town due to the 'sea' breeze
Reading the Otago Daily Times today there was a very short piece about the record breaking cold Reefton has recorded recently. Having lived in Reefton for 5 years until late last year, (and measured the weather for 4+ of those years), this interested me obviously. According to the article, the town recorded lows of up to -11°C over the last few days, with these types of temps not seen since 2001.
Of course, that is absolute rubbish. What happens is that the "official" local weather guy who is often quoted in the local rags (and not even local ones it seems) and on the local radio stations appears to confuse grass/ground mins with air temperatures. So he quotes these very low temperatures values as "air" temperatures to the media who run with it, and everyone thinks that these are real....when they're not.
I find this frustrating, as Reefton doesn't have a lot going for it at the best of times, so to continue to perpetuate the belief that the town has pretty rubbish weather, which is definitely true for the winter months, but definitely incorrect for summer, I find rather annoying.
The NIWA site in town recorded a low of -6.9°C yesterday, which is undoubtedly cold (my lowest recorded temp on my crappy EWS was -6.4°C from memory). On that same day the minimum grass temperature was -10.9°C. Viola, there's the story, or lack thereof. For interest sake, I checked out 2001, which recorded a lowest air temp of -8.3°C, with a matching grass min of -10.5°C.
Einzack, Otago Daily Times would have picked this Grey Star story up from APN and butchered it.
This is the Westport News version from the same source:
Reefton yesterday experienced its biggest frost
for 15 years, registering a ground temperature of
minus 11degC. Weather observer Tony Fortune
said the township had been recording ground
temperatures of minus 10degC for the past three
days.
``We have had perfect weather and nice fine
days. In 2001 we recorded a ground temperature
of minus 12,’’ Mr Fortune said. Greymouth Star
lokeynz wrote:Einzack, Otago Daily Times would have picked this Grey Star story up from APN and butchered it.
This is the Westport News version from the same source:
Reefton yesterday experienced its biggest frost
for 15 years, registering a ground temperature of
minus 11degC. Weather observer Tony Fortune
said the township had been recording ground
temperatures of minus 10degC for the past three
days.
``We have had perfect weather and nice fine
days. In 2001 we recorded a ground temperature
of minus 12,’’ Mr Fortune said. Greymouth Star
Sounds very accurate to me, he clearly talks about ground temperatures, not air temperatures...
Indeed, that version does mention ground temperatures. I may not have read the ODT version correctly, (or they butchered it as you suggest), so may be being unkind to Mr Fortune on this occasion, but my memory of reading and hearing similar stories from when I lived in Reefton was that the distinction was rarely made (and definitely never understood by the general public).
Because some locals knew that I had a personal EWS they would often approach me and ask me about it cause they heard on the radio or read in the Grey Star or Westport News that Reefton got to some massive low temperature and wondered what I had recorded. I would then have to explain to them, that no, what they thought they had heard wasn't actually the case at all. My kids would come home from school and ask me about it as well because their teacher had spoken about it in class. That kind of stuff. All referencing it as air temps.
I appreciate that this side of it is because people are ignorant about the nomenclature specific to weather, but the journalism involved is feeding off that as well.
The lower the number the better the story, even if the lower number doesn't actually mean what you think it does.
And back to the weather, Reefton has obviously had some cracking days over the last week - a temperature range of 19.1°C yesterday is impressive for winter.
5 years ago today it snowed in Auckland , http://www.nzherald.co.nz/nz/news/artic ... d=11693646
There was certainly snowflakes over southern/ sw parts of the region. My experience of the day was snowflakes near Pukekohe and soft hail in Mt Eden.