CLIMATE - LOOKING INTO APRIL AND THE FIRST HALF OF MAY.

The weather is certainly very active in large areas of the west, north and east in the short term, following the script in these updates from 4 weeks ago, while we were seeing the severe weather events over the east. The middle of the month, settled and quiet with high pressure and drier air coming in and then we would then see a gradual increase in moisture via the approach of the MJO (we saw that this weekend) and the SAM tending back to a positive stance (which are seeing now).


This is leading to the active weather in the short term, but it is likely that we will see additional severe weather events in the coming 4-6 weeks as we continue the transition into the cooler season?


Does the wet season linger beyond normal over the north, continuing the widespread rainfall opportunities across the nation? Do we see further ECLs? Do we have late season cyclones feeding the northwest jet stream, bringing above average northwest cloud bands?


We have covered off the remainder of March in the short term forecast this morning, so lets go further ahead.


More information to come on that in the video below.

FORECAST

%chance of exceeding or not exceeding the median rainfall for the next 6 weeks

There does appear to be evidence that the rainfall distribution is continuing to shift to being biased over the southern parts of the nation, especially over the southwest and west with elevated SSTs in the Indian Ocean playing out as higher moisture and rainfall chances for the region. The lingering monsoonal weather over northern Australia that takes us into the first half of April could lead to well above average rainfall through northern Australia but how far that penetrates southwards is down to each individual tropical lows that form. The east coast likely to see above average rainfall as the lingering La Nina does support the continuation of positive SAM phases through the coming 4 weeks (as seen in recent attempts for negative events, these are softened in reality and then the swing back to a positive phase is verified leading to more showery outbreaks and storms inland). The southeast through to southern coastal areas of the nation should see relatively seasonal falls for now through this period with the drier bias extending northwards through to the Central Interior. Overall, the period does favour more above average rainfall, more severe weather events which may be distributed more evenly across the nation with the west also getting involved in the risk and the lingering wet season could see some areas recieve near record rainfall with landfalling tropical systems. If the latter happens then widespread above average rainfall across the nation is likely to occur.

%chance of exceeding or not exceeding the median temperatures for the next 6 weeks

The temperature spread changing a little from last week, where we see the west tending a little cooler thanks to more rainfall and cloud moving into the forecast package (being May that is the start of the wet season for the west.) The east also relatively seasonal, the above average SSTs keeping the overnights warmer but the day times cooler with more rainfall expected on and east of the divide. The interior parts of VIC, NSW, QLD, SA and the NT could be warmer than normal with ridging close by and the chance of slack pressure patterns continuing, so there could be a large area of inland Australia seeing warm air dam over the region, even in the presence of rainfall remaining seasonal to above seasonal.

Key Points

More details in the video at the top of the page

Additional Key Points To Consider

More context to think about as we move through the seasons, things are starting to move.


More to come on this product on Friday but also watch for further climate information including the outlook for April to June in greater detail in the coming days.


Tomorrow I will have a look at the Climate moving through April and June as a seasonal outlook and break down where things may be heading for the nation






166 views0 comments