Thread by @althecat

These Canterbury Floods are moving in to Otago.

https://twitter.com/althecat/status/1398869729306202118

Here is a wider view. This will definitely continue through a fair bit of the night. Question is now how long will it continue tomorrow? The forecast models showed the plume you see coming in from the right sort of petering out and disengaging and tracking north.

A wider view.

These images show where the most recent global models thought it would be at the moment (6pm today). In order ECMWF, GFS, Access-G and CMC.

According to the models the rain band should start moving back to the north again about now, but this time with much less rain.

Here are two versions of the next 48 hours. This is the latest GFS Version.

And the latest GFS version.... basically identical.

Bear in mind that each frame is 6 hours apart and in many ways the most important point in this drama is right now as the source of moisture begins to pull away to the East.

A close look at the satellite images suggests this storm has stopped tracking south and has been stationary from 3.40pm to 5.40pm NZT.

If the predictions are correct - as it seems they are - it should start moving northwards fairly soon. Back into @grenow territory, Waipara.

And the good news is that as this happens this should also happen. I.E. it should get both weaker and accelerate as it moves north. I.E. in theory the vast bulk of the heavy rain has already fallen.

This animation begins with rain over the last 6 hours (1st frame - forecast not actual) then what is forecast the next 48 hours.

I.E. if you subtract what you see in this first picture from the 2nd. that will give you a rough estimate of what remains. In the red areas that is about 30-40mm & maybe 30mm more in the dark patch.

Also Note: This is not a forecast & I am not a meteorologist.