SA - STORMS INCREASING TODAY WITH HEAVY FALLS FOR SOME

And the potential for severe weather for some parts of the Agricultural areas which is possible tonight through Wednesday.


An upper trough is deepening as I type and that is linking into substantial moisture being drawn in through the upper level northwest winds from WA, where recent rainfall has caused flash flooding. The rainfall rates now over parts of the Eyre Peninsula and West Coast could rival what brought flash flooding in recent days over WA.


Lets take a look


FORECAST

Rainfall Next 5 Days

Rainfall remains widespread for the western Agricultural areas with a sharp trough linking into that moisture as you can see in the data sets below, leading to showers and thunderstorms and the moderate risk of flash flooding later today and into Wednesday morning before the risk eases and the trough weakens. Some areas could see 1-2 months worth of rainfall, once again highlighting the impact of a storm outbreak bringing the higher rainfall, rather than drawn out rainfall events over the course of 2-3 days. The rainfall will be uneven in distribution with some getting clobbered and some missing out. The heaviest of rainfall should stay mainly west of Adelaide.

Flash Flood Risk - Tuesday

Heavy rainfall developing with thunderstorms is a moderate risk over the Eyre Peninsula and through the West Coast with slow moving thunderstorms this afternoon and this evening. Areas of moderate to heavy rain may also develop overnight which could fall over areas still recovering from heavy rainfall and the flooding from January.

Thunderstorm Forecast Tuesday into Wednesday

Current guide has the thunderstorm activity increasing in coverage tonight through to before dawn Wednesday and this activity peaking through the morning before spreading east over water through the YP before weakening into areas of rain as the upper disturbance washes out throughout the day. Locally heavy rainfall leading to flash flooding the main concern for now from later today through to about 9am Wednesday.

DATA

Satellite Imagery

You can see the thickening cloud cover in response to the upper low approaching from the Bight. Rainfall is expected to increase in coverage and thunderstorms also likely to increase this evening and overnight. Some thunderstorms are expected to deliver flash flooding over the Eyre Peninsula and back towards the West Coast. Just high and middle level cloud and a few spots of rainfall making it as far east as Adelaide at the moment.

Euro 12Z - Surface Pressure Pattern and Rainfall Distribution - Next 3 Days

The rainfall is expected to increase in coverage over the EP today, we can already see a lot of activity on the radar and that is likely to peak this evening between 6pm and 6am with activity winding down tomorrow morning and contracting east and clearing. There will be lighter falls further east.

Euro 12Z - Precipitable Water Values - Next 3 Days

A deep supply of moisture near 50mm will result in productive showers and thunderstorms once again. Some areas could well record more than 50mm of rainfall with thunderstorms. The air will modify to dry tomorrow and more settled conditions expected with the drier air developing this time tomorrow.

GFS 18Z - Rainfall Accumulation - Next 3 Days

The bullseye starting to look more likely over the EP with the heaviest rainfall expected tonight and through Wednesday morning.

Euro 12Z - Rainfall Accumulation - Next 3 Days

Some areas if this is correct could see falls up to 70-80mm over the coming 24hrs. That is conceivable given the moisture content and instability in the region and the slow motion of thunderstorms through the region.

ICON 18Z - Rainfall Accumulation - Next 3 Days

The latest ICON spreads the moderate rainfall shield over the YP and into Adelaide with broader widespread falls across the EP but stopping short of moving over Whyalla with areas north remaining mostly dry under this solution.

CMC 12Z - Rainfall Accumulation - Next 3 Days

The model not as interested as the above three showing less rainfall and less instability over the coming 12 hours.

Stay weather aware today with the risk of severe weather high this afternoon.

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