Oct 23 - North Island low pressure / rainband

[Cyclone Tracy]

I thought it might be worth creating a topic for this one. Access R and EC a fairly aligned on a 30 to 50mm event over the upper north island with Auckland potentially in the attack zone for the rainband and possible imbedded storms. GFS and Icon has the intense area of the rainband further south.

[Cyclone Tracy]

Atmospheric river starting to flow nicely
http://tropic.ssec.wisc.edu/real-time/m ... anim=html5

[NZstorm]

I hope we can get 20mm+ out of it to water the garden. There will be some low CAPE convection there which will produce an embedded heavy shower of two so hopefully we can catch one of those. Lightning chances look low though due poor lapse rates. For lightning I like to see parcels hitting -30C. That will be a struggle tomorrow though not impossible.

[Cyclone Tracy]

Access R and EC still thinking 25 to 30mm for Auckland today on the 12z run. GFS still pushing the heavier portion further south. Precip water flowing into the convergence at around 30mm.

[NZstorm]

The wind change will cross Auckland late afternoon, we may get a brief convective downpour with that.

[Cyclone Tracy]

MetService have just issued a severe thunderstorm watch

Issued by MetService at 09:17 am Monday 23 October 2017
Valid until 05:00 pm Monday 23 October 2017
This watch affects people in the following weather forecast districts:
Northland
Auckland
Great Barrier Island
Coromandel Peninsula
Waikato

[Cyclone Tracy]

Scored a lack lustre 10mm from the frontal rainband. Just didn't have cold enough uppers to set it off. Plenty of spots around Auckland had around 15mm from what I can see.

[NZstorm]

Scored a lack lustre 10mm from the frontal rainband. Just didn't have cold enough uppers to set it off. Plenty of spots around Auckland had around 15mm from what I can see.

Just 11mm here.

I didn't expect lightning with this system as the lapse rates looked poor. If lightning occurred it would be isolated.