Their memories are short.
YTD for Christchurch airport 412mm.
Jan to Oct 2015 398mm
Jan to Oct 2007 424mm
Jan to Oct 2005 362mm
Jan to Oct 2003 411mm
Jan to OCt 2001 334mm
Their memories are short.
Sorry Tony but Chch Aero is not Halswell or the peninsula. 253mm YTD for us in Halswell. Many Chch and Peninsula sites are also under 300mm
Hmm… I only get 368mm YTD to 11pm last night for Chch Aero?
Thanks Nev- that certainly corroborates with the discussions I've been having with locals - farmers and residents, not to mention what we are experiencing on the ground. Cooptown (little River) would be a typo at 913 thoughNev wrote: ↑Tue 27/10/2020 06:34Hmm… I only get 368mm YTD to 11pm last night for Chch Aero?
Here's a few other 2020 rainfalls to 9am yesterday (i.e. not counting last night's rainfall):
MetService & NIWA 2020 YTD Rainfall (mm) to 9am on Oct 26th
362 … Chch Aero
282 … Riccarton
205 … Bromley
275 … Lincoln
235 … Lyttelton
913 … Cooptown
I think Chch's driest full-year on record by far would have to be 1988 with 306mm at Chch Aero and 293mm at Chch Gardens.
Sorry, yes, I was summing the previous year's figures, you are right its 368mm YTD for 2020 (plus whatever fell in the last 24 hours). The downside of doing those calculations late at night!Nev wrote: ↑Tue 27/10/2020 06:34Hmm… I only get 368mm YTD to 11pm last night for Chch Aero?
Here's a few other 2020 rainfalls to 9am yesterday (i.e. not counting last night's rainfall):
MetService & NIWA 2020 YTD Rainfall (mm) to 9am on Oct 26th
362 … Chch Aero
282 … Riccarton
205 … Bromley
275 … Lincoln
235 … Lyttelton
913 … Cooptown
I think Chch's driest full-year on record by far would have to be 1988 with 306mm at Chch Aero and 293mm at Chch Gardens.
And heavier rainfall.
ChCh Aero is seemingly a significant anomaly in the whole territorial boundary of ChCh City and BP this year- many of the rain events have focus on areas to the north of town this year (Airport is much closer to there of course) A number of good rain events have completely bypassed most of the city in general, as evidenced in the figures in Nev's post. I'd love to know the trends for those over the years, certainly when looking at Jeff Northcotts site in Hoon Hay for eg (which is close to us) he is approaching a 300mm deficit in regard to his his 10 year average. A massive drop off.TonyT wrote: ↑Tue 27/10/2020 11:08Sorry, yes, I was summing the previous year's figures, you are right its 368mm YTD for 2020 (plus whatever fell in the last 24 hours). The downside of doing those calculations late at night!Nev wrote: ↑Tue 27/10/2020 06:34
Hmm… I only get 368mm YTD to 11pm last night for Chch Aero?
Here's a few other 2020 rainfalls to 9am yesterday (i.e. not counting last night's rainfall):
MetService & NIWA 2020 YTD Rainfall (mm) to 9am on Oct 26th
362 … Chch Aero
282 … Riccarton
205 … Bromley
275 … Lincoln
235 … Lyttelton
913 … Cooptown
I think Chch's driest full-year on record by far would have to be 1988 with 306mm at Chch Aero and 293mm at Chch Gardens.
My point still stands though, as 2005 was 362mm, 2001 334mm for the same period. You don't need to go back to the 1960s to find a comparable period.
Obviously some other sites are lower than Chch Aero, but you would need to see how they fared in past years also. Dry spells are funny things - quite small, localised areas can be very much drier than surrounding areas, but it all evens out in the end. North Canterbury was in exactly that position about 5 years ago. Some tiny pockets got hardly any rain for 2 years, despite the surrounding region being droughty for a shorter time, and the broader Cantery region looking quite green.
Having said that, the coastal area from central Chch through to the coast but not including the Peninsula is probably the driest part of Canterbury, long term.
Would it not lower the contrast between the temperature of the land and immediate ocean, lowering the pressure gradient and weakening the wind? So less wind chill from the easterly.TonyT wrote: ↑Tue 27/10/2020 12:04And heavier rainfall.
Actually, there is a small feedback loop locally where warmer temperatures immediately offshore Canterbury lead to stronger northeast breezes which in turn can make the land area cooler. So warmer temperatures are not locked in, right on the coast.
Yes. But how often do you find the NE has started in the morning with the land temperature colder than the ocean temperature? Enough to tell us there is more going on. Many days the Canterbury nor'easter is not a true sea breeze, so its presence and development is not hugely affected by land/sea temperature contrasts. (Some days it is). There is a complex feedback cocktail of various factors in there, none easy to isolate on their own.Chris W wrote: ↑Tue 27/10/2020 12:54Would it not lower the contrast between the temperature of the land and immediate ocean, lowering the pressure gradient and weakening the wind? So less wind chill from the easterly.TonyT wrote: ↑Tue 27/10/2020 12:04
And heavier rainfall.
Actually, there is a small feedback loop locally where warmer temperatures immediately offshore Canterbury lead to stronger northeast breezes which in turn can make the land area cooler. So warmer temperatures are not locked in, right on the coast.
Lincoln Jan to OctRazor wrote: ↑Tue 27/10/2020 12:20
ChCh Aero is seemingly a significant anomaly in the whole territorial boundary of ChCh City and BP this year- many of the rain events have focus on areas to the north of town this year (Airport is much closer to there of course) A number of good rain events have completely bypassed most of the city in general, as evidenced in the figures in Nev's post. I'd love to know the trends for those over the years, certainly when looking at Jeff Northcotts site in Hoon Hay for eg (which is close to us) he is approaching a 300mm deficit in regard to his his 10 year average. A massive drop off.
I stand by the fact that its an incredibly and now seriously dry year for a lot of people here and that many sites are under 300mm YTD within the boundaries of Christchurch City Council (includes the Peninsula). In my view I'd like to find those longer term stats (but don't really know where to look quickly) and I can genuinely believe the situation is much more serious and widespread than the ChCh Aero figures will lend us to believe
I'd say I mostly peg it for starting around 1-2pm after the thermal gradient at the surface has developed via heating, or at least it intensifies after that, but I've never written that down. So I can't really contest what you've said and it's quite interesting to consider whatever else could be involved .TonyT wrote: ↑Tue 27/10/2020 13:28Yes. But how often do you find the NE has started in the morning with the land temperature colder than the ocean temperature? Enough to tell us there is more going on. Many days the Canterbury nor'easter is not a true sea breeze, so its presence and development is not hugely affected by land/sea temperature contrasts. (Some days it is). There is a complex feedback cocktail of various factors in there, none easy to isolate on their own.
Geez, where do you live? Most summer days the NE is starting by 9am in Christchurch and for most of the eastern Plains. Ian McKendry wrote a phD thesis on it years ago and I helped with the field research. Bottom line is, most of the time its not a true sea breeze, its a trough induced wind which runs down the east coast of the SI as outwash from Cook Strait. But it does have a sea breeze component, which varies from day to day in how great a contribution it makes. The interesting thing is often the NE starts inland and works its way towards the coast - ie its present at Darfield or West Melton before it arrives in Christchurch or Rangiora.Chris W wrote: ↑Tue 27/10/2020 13:45I'd say I mostly peg it for starting around 1-2pm after the thermal gradient at the surface has developed via heating, or at least it intensifies after that, but I've never written that down. So I can't really contest what you've said and it's quite interesting to consider whatever else could be involved .TonyT wrote: ↑Tue 27/10/2020 13:28
Yes. But how often do you find the NE has started in the morning with the land temperature colder than the ocean temperature? Enough to tell us there is more going on. Many days the Canterbury nor'easter is not a true sea breeze, so its presence and development is not hugely affected by land/sea temperature contrasts. (Some days it is). There is a complex feedback cocktail of various factors in there, none easy to isolate on their own.
yes, thats how I have understood itBottom line is, most of the time its not a true sea breeze, its a trough induced wind which runs down the east coast of the SI as outwash from Cook Strait.