NZ Weather Forum

I see, Metservice has mucked up the data retrieval services (JSON) for the Auckland Forecast, currently Auckland has Rain icon for today and the text contains to days in it.

^ Akld now only has the sun-symbol for today and no text.

Yeah, their Weather Severe Watch, this morning, didn't make much sense, well the first sentence.
An active cold front is moving up the North Island today, reaching
the lower North Island Friday morning. This front is preceded by
heavy rain in the west and strong, gusty northwest winds in the east.

Shouldn't that read moving up the South Island?

And I see the radar image finally has the outline of NZ laid over the top

I see that they have added the overnight Lows to the temperature forecasts, nice

And I see the radar image finally has the outline of NZ laid over the top

yes, I meant to say thanks for that too as I had noticed that recently

A little Glitch on the Auckland Weather Update on Metservice TV.
Dan doesnt look impressed, LOL

The new layout for chch ( http://www.metservice.com/towns-cities/ ... ristchurch ) seems not to have humidity, or am i missing something

It seems you are right CS,

I cant find any hourly observations on the new Christchurch section nor the updated Auckland section.

Yes, it seems their 'live' Akld, Wgtn, Chch upgrades also no longer seem to include rainfall or baro obs. Hope that's just a temporary glitch. On the plus side, we get up-to-date wind obs for the sub-regions.

P.S. I see there's also no longer a link included to Ashburton on MS's Chch page. So (unless you know the url) there's now no way to navigate to that Ashburton page.

Nev wrote:P.S. I see there's also no longer a link included to Ashburton on MS's Chch page. So (unless you know the url) there's now no way to navigate to that Ashburton page.

Not as convenient but you can still get to the Ashburton page using the "towns & cities" dropdown menu or the Town & City forecast page.

Oops. Thanks Steven; completely forgot about those menus.

i notice this morning on the MS website that they have Rakaia on a +10deg over night low,they have Darfield 5 deg and Waipara 13 deg,all of these centres will have frosts,so Waipara's temp could be as much 16 deg incorrect.

They seem to have some pretty major errors on their site at the moment, this is just one example:
Most South Island locations have these temperature errors going on, and some places in the NI too

Wow ,yes a bit sloppy on there part

MetService haven't updated forecast (for midnight tomorrow) since this morning.

Yeah Met had pretty decent internal technical issues on Thursday. Our upper air flights weren't filing. Sh*t happens

Hmmm, is it just me or does the term frost need to be redefined?

Tornado Tim wrote:Hmmm, is it just me or does the term frost need to be redefined?

Yes because it does tend to cause confusion with people who have limited understand of weather,i remember having this discussion with a neighbour about TVNZ's weather when doing the fly over,Jim saying "frosty for CHCH going down to 3deg overnight,gees i couldn't get it through to my neighbour that you cant get frost at three deg.

^ Umm... Your neighbour is correct. On a calm night/morn, the temp near the ground may be as much as 4C cooler than the forecast overnight air-temp.

Good article about Frost by Bob McDavitt here.

make sure you are talking about the same thing...air temperature measured at 1.8m off the ground...which can easily be above freesing,and grass minimum temperature, at grass level, which can freezing or below (i.e a ground frost (occuring due to long wave radiation heat being lost to space from the earth surface which cools the layer of air just above the earths surface) as opposed to an air frost)

Nev wrote:^ Umm... Your neighbour is correct. On a calm night/morn, the temp near the ground may be as much as 4C cooler than the forecast overnight air-temp.

Good article about Frost by Bob McDavitt here.

Well i dont know about that a 4 deg difference i noticed often that frost will start to form on grass at the same time as it does on the roof of the car and the height of a car roof is a little lower than what should be the correct height for a airtemp gauge

Yes, ice/frost will usually form on car-roofs and glass windscreens before it forms on plants or the ground because metal and glass cool much quicker than most other materials.

yes, same principle, in regards to the car roof, its the same as the ground loosing heat to space (long wave radiation) (if you measured the air temperature just above the car roof it would be colder (assuming no wind), as the cold car roof would be cooling down the air
think of the earths surface or the car roof as a black body, at night

In my experience, if the 1.8 meter low temp is 6°C (like in the forecast), there wont be a ground frost.
If its 3°C on the other hand, yes its possible.

Perhaps they should be a little more specific in the forecast, say isolated frost in sheltered locations. Because them saying fine and frosty means that its more of a widespread frost, but thats unlikely when the temp at 1.8m is 6°C.....