Case study of Rain event in western Victoria. Australia 13th July 2013


This event was unusual in that the surface winds came from the north east. Usually our pre-trough cloud bands are associated with a North westerly wind.

Synoptic wind stream patterns at all Atmospheric layers 13th July 2013 Thanks to . BOM

I was amazed that we are getting quite wet with a North easterly surface wind stream in the prefrontal cloud band.

This is not so common here in Dunolly close to the Wimmera district, as prefrontal bands are usually only rain bearing with a strong n/westerly wind moisture laden from the Indian ocean

Seeing as it is wet weather day here. Time on hands inside. So l Ttought l would compose a case study on this rain event for today

The wind change line to a south westerly doesn’t arrive until about later tomorrow( Sunday)

So all this wet stuff is amazingly ALL pre-frontal cloud with a north east surface wind!

Here is my collage posted below

A few points added for the analysis

-Moisture is in-feeding in from the north east from a North / south elongated high in the Tasman sea
-At the mid and upper levels the air flow comes from the west
-There is a surface, mid and upper trough/low in the Bight area approaching VIC/colder latitudes in-putting into this event today as the eastern quadrant of the arriving low
-The polar Jetstream is contracted well south and zonal and seems to be locking the cold Antartic air well south of the OZ mainland assisting in keeping temps’ relatively warm for this rain event in mid winter/JULY

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