Easterly rain from the SW

[NZ Thunderstorm Soc]

I consider this as an interesting event as this system here had winds been between west and south which was probably felt all over the ChCh area...but the weather ie. substantial rainfall has come from the east or NE.
Yesterday,cloud movement was from the east to NE but the 'Old Man Southerly' just hung in there.
This, last night as the rain fell, was blown in from the WSW here but the major system above was obviously moving south judging by the rain radars and the frontal movement.
Now that the frontal system has moved away, the is a slight NE here and a clearing sky


JohnGaul
NZTS

[Manukau heads obs]

maybe for your location the wind was coming around the port hills (i.e ESE bent southerly?)

Immmmmmmmmmm that's interesting
Seemed to be more WSW than a more South or SE if so???
When the lower SW cloud cleared away yesterday, there was a distinct from the NE movement from the cloud above, yet the surface wind maintained it's SW or WSW flow.
MetService had maintained it's easterly forecast which made sense, but the easterly or NE did not eventuate here or anywhere in Christchurch, to my knowledge, with the rain. All wind was from the SW or even further to the west direction?
Would BP have that much influence on windflow in these circumstances?
JohnGaul
NZTS

[gllitz]

Yes, John, I noticed that as well...you can see it quite clearly in Jeff's page here (under Graphs-->7 Days graphs):

http://weather.northcott.co.nz/index.ph ... &Itemid=42" target="_blank

...and it can be seen in the graphs here:

http://www.zl3gp.co.nz/wxlive/index3.php" target="_blank (changes with time, so depends when you look at it...)

I was a bit confused as well by the winds...S/SW all day on Sunday, or so it seemed, but clouds were moving in from the N/NE...

[Lawrence]

I think you may find this interesting and may explain things http://en.wikipedia.org/wiki/Wind_shear

[Manukau heads obs]

there was though a wave depression moving down on that front to the east of CHCH
i.e causing those WSW winds inland ?

[RWood]

I'm told that a strong SE flow in the area causes local westerlies over Kaikoura - the small matter of the mountains may have something to do with it...