General October Weather

[David]

The Davis rain gauge does tend to under read by 5%

Since are worse than that, when I calibrated mine about 7 years back I found it to be reading over 10% lower than the manual gauge I used for reference, over a period of months.

[cbm]

The Davis rain gauge does tend to under read by 5%

Since are worse than that, when I calibrated mine about 7 years back I found it to be reading over 10% lower than the manual gauge I used for reference, over a period of months.

They cost enough, thought it would be better than that. If anything the wedge type manual one should under-read due to evaporation,and because the narrow opening could miss wind blown/sideways rain?

[Willoughby]

Can't you just adjust the screws on the Davis rain gauges to calibrate?

[Awhituobs]

yes you can do that too

[Cyclone Tracy]

Also, Davis in the last couple of years bought out the new AeroCone that fits the Vantage Pro 2, which has improved the accuracy issues caused by the horizontal wind velocity, splash outs and debris. I have one and it's been spot on.

[Awhituobs]

that aerocone does look good
but does mean in cold climates you cant so easily put a snow heater inside the cone

[David]

Can't you just adjust the screws on the Davis rain gauges to calibrate?

Yep that's how I did it, incrementally adjusted them until I was happy with the results.

With regards to the manual gauge I used it wasn't a wedge, but funneled the rain drops down into an enclosed tube, so evaporation shouldn't have been any issue. Model is nylex 1000

[NZ Thunderstorm Soc]

With regards to the manual gauge I used it wasn't a wedge, but funneled the rain drops down into an enclosed tube, so evaporation shouldn't have been any issue. Model is nylex 1000

I use a Nylex 1000 which I fine quite accurate and better than ones that might be better from a tipping system used from automatic weather systems.
No problems here from going out and reading rainfall on a regular basis, as I keep it clean so no build up of gung at the bottom of the cylinder.
Manual wedge shaped rain gauges are useless as gunk tends to build up and hard to clean, hence incorrect rainfall readings.

[jamie]

My nylex and Davis can be +/- 15% but that goes both ways. They are only 20m apart. More often tho the nylex records slightly more. Very often they are within a couple mm. But yea on the big prolonged falls 15% different can be seen.


Sent from my iPhone using Tapatalk

[NZ Thunderstorm Soc]

For the month, the total rainfall here was 59mm over 22 days, with 2 days of AFD and one of trace.
2 claps of thunder were heard on the morning of Thursday the 24th from a cloud moving north from the SW with some bits of hail.
The maximum temperature for the month was 29.4C, last Saturday in calm ENE conditions.
6 frosts were recorded.

[Nev]

MetService October 2019 Summary - 'Low pressures targeted New Zealand'

Weather patterns were unsettled, and a real mixed bag, during October. The month was characterised by much lower pressures than usual over New Zealand. October started off with cold southerlies, before the Tasman Sea delivered a couple of rainmaker lows (bringing rain to eastern areas) through the middle of the month. Stormy westerly gales kicked in with a vengeance during the last 10 days of October.

Not surprisingly, temperatures bounced around. The month started out an exceptionally cold, nationally, but subsequent warmer spells meant that the October monthly average temperature ended up near average for most North Island regions. In contrast, monthly temperatures were below average across most of the South Island, most notably in the east.

It was a wetter than usual October along the eastern coastline of both Islands (excluding the Kaikoura Coast), as well as the west and south of the South Island. In contrast, the western North Island ran a touch drier than usual, while Nelson and Marlborough recorded near average totals.

Oct 2019 Climate Anomaly Maps ℅ NIWA.gif

Some very preliminary Oct 2019 figures for the main centres:

Code: Select all

Oct 2019 Average Temps, Rainfall, Sunshine and departures from 1981-2010 normals ℅ NIWA

Site                     T-max °C      T-min °C      T-mean °C     Rain mm      Sun hrs

Auckland, Mangere       17.8  +0.2    11.6  +0.5    14.7  +0.3     75   83%    188  107%
Auckland Aero           17.7   0.0    11.6  +0.4    14.6  +0.1     69   73%
Tauranga Aero           18.5  +0.4    10.1   0.0    14.3  +0.2     91  102%    n/a   n/a
Hamilton Aero           17.9  -0.1     8.7  +0.7    13.3  +0.3     56   57%
Hamilton, Ruakura       17.7  -0.3     9.0  +0.6    13.3  +0.1     66   72%    154   87%
Wellington, Kelburn     15.0  +0.1     8.7  -0.3    11.8  -0.2    122  104%    191   99%
Christchurch Aero       16.3  -0.6     5.1  -0.9    10.7  -0.7     61  124%    201   99%
Dunedin, Musselburgh    13.7  -1.0     6.9  -0.2    10.3  -0.6    121  196%    171  102%
Greymouth Aero          15.0  -0.1     7.5  -0.5    11.2  -0.4    307  136%    187  119%

[Awhituobs]

will be a close call if those eastern SI readings will drag the whole country average down below the -0.5c threshold
i.e that -0.7c is balanced by NI stations 0.3 above
i.e country as a whole might end up right on the -0.5c or maybe -0.4c

[RWood]

I'm guessing the 7SS will come in at about -0.3C or -0.4C. The NIWA anomaly map suggests something similar.

[David]

Howick summary for Oct 2019

Posting late because I had to do some small data edits due to the fan being obstructed from spinning on the 30th/31st, which looks to have produced too-high daytime temps on those days.

Mean temp = 14.2C
Mean daily high = 18.2C
Mean daily low = 10.8C
Highest temp = 21.6C (27th)
Lowest temp = 5.7C (3rd)
Total rainfall = 101mm, YTD 984mm

[Awhituobs]

Your ytd rain is similar to mine
But seems other area of Auckland much less

[Nev]

Here's NIWA's preliminary, 'October 2019 National Climate Summary'.

Variable rainfall patterns; cool in the lower South Island


The national average temp of 11.8C was 0.3C below normal.

The month's highest temp of 29.0C was recorded at Methven on the 26th.
And the lowest temp of -5.9C was recorded at Lake Tekapo on the 23rd.

[Richard]

Medbury Oct readings.
rainfall - 63.0mm
max temp - 25 deg 28th
min temp - -2.2 deg 4th