Roger Rowswell’s monthly rainfall report for May 2021
At Darling Street a total of 37.1mm was recorded for the month over 7 rain-days compared to the long term average (LTA) of 31.2mm and a long term median (LT Med) of 20.7mm. So for a change, both LTA and LT Med have been exceeded. The highest and lowest rainfalls recorded in May in the past are 151.3mm and 4.9mm respectively.
The thunderstorms that occurred early – 5, 6and 7 – and later (20 May) were a good omen for weather change. The rainfall over the four days, 5-8, was also was also very welcome. A total of 30.7mm was measured in Darling Street. Let’s hope they continue for the remainder of the month and on. Although the rainfall in May has been pretty sparse, it has surpassed the month’s LT Med and LTA. Looking at the graph below, the monthly rain for May 2021 has exceeded for the first time since January the long term values for Darling Street. This is in keeping with the trend of 1922.
The last time the ONI (Ocean Nina Index) was reported was in March, where it stood at -1.1 for January. Since then, both the February and March values have been obtained which both stand at -0.9. I am eagerly awaiting the figure for April: will the La Nina persist through to June? Remember, the ONI must stay at or below -0.5 for the La Nina phase to continue.
Park Road Monthly figures for May from Jim Cambray
Total for May 2021: 30.2 mm
36 year Average: 31.1
36 year Median: (36 years) 19.6mm
36 year Range: 5.4mm (2010) and 137.0 (2011)