Subtropical low for Northern NZ Sunday/Monday

[NZstorm]

GFS is still running with the idea of a weak low pressure system of subtropical origin affecting northern NZ Sunday to Tuesday timeframe. The last run of the ECMRF backs this. Some rain is modeled for northern areas Sunday/Monday. By Monday high dewpoint air should be across the North Island and daytime heating/convergence leading to a convective risk inland.

[Vertigo]

the initial cloud cover has reached auckland now, light spotty rain falling, but id say were in for a day of boring dreary weather until the bulk of this system reaches here.

[NZstorm]

What happened to our sunny weather? Some showers here this morning but they look to have cleared. Notice there is a halo in the high cloud. Looks like the rainy weather with this low will come through Monday. Not sure whether we'll get much in Auckland. GFS is all over the place on rainfall chances. The upper level support looks a lot weaker than the last system a few days back. Airmass is set to warm up considerably by Monday with the chance of hot temperatures next week depending on how much sun we get. Looks to be at least low thunderstorm chances Monday/Tuesday over the North Island.

[Manukau heads obs]

DP certainly higher today
bit conveyor belt of cloud/moisture coming down from the north at the moment
but I cant see any real focal point at this time...yet...

[Vertigo]

well the rain arrived this morning. fairly wet, not especially heavy, and the system seems to be breaking apart. still, a decent dumping. bring on the '09 cyclone season! these past months have left me wanting.

[Nev]

Still light rain here. Arrived just before 7am - 6.2mm so far - more than twice that of the city by the looks - 25mm at the Coromandel's Pinnacles since 2am ...

[NZstorm]

These subtropical lows tend to muck the weather up for a few days. Just 8mm in Grey Lynn. Airflow over Auckland today should be WNW which may clear our weather up today.

Airflow this week is originating from the north hence should be a warm week across NZ. East coast NI should get 30C+ temps.

[Vertigo]

were in a nice pattern of lows, i just wish one of them would turn cyclonic..

[Manukau heads obs]

looking like la nina type conditions for the rest of summer?

a sub tropical low and TC are 2 different things...

[TokWW]

Sth Waikato - 12mm of rain yesterday to 9am this morning and drizzling again now, it may clear later on but stay cloudy. Weather is unstable and light winds. Baro turned at 1006hPa and rising slowly now. Weather projects in the garage today I think...

[Brassnz]

Laingholm - 22mm rain yesterday to 9am this morning. It felt like we were getting more than that as the rain was really hanging around the Waitakeres yesterday.

[Nev]

Yes, I can believe those higher totals for Laingholm/Titirangi. Also quite exposed the SE'ers there - often turns some of the more shelly beaches into sandy ones.

Ended up with 9.5mm in total here since 7am yesterday. Still very happy with that - tanks are about 80% full now. Very warm and humid last night with T-min of 18.2°C this morn. See the Pinnacles on the Coromandel are up to about 100mm since 2am yesterday.

[Vertigo]

a sub tropical low and TC are 2 different things...

of course. i meant that these lows were of tropical origin, and it would be nice for one of them to turn cyclonic before it left.

[Manukau heads obs]

still different...these lows are not forming as far north as were a TC forms...

[Myself]

a sub tropical low and TC are 2 different things...

of course. i meant that these lows were of tropical origin, and it would be nice for one of them to turn cyclonic before it left.

They weren't of tropical origin. They formed as a typical mid-latitude low pressure system with warm and cold advection circulating about a centre (just look at the analysis charts from when they were just forming). TCs form completely differently and then "pick up" a warm front and cold front as they transition into ex-tropical cyclones. Our recent lows formed between 25-30S, never any chance of getting a TC forming in those waters. Our typical TCs form near the Solomon Islands or similar latitudes.