Rain event 22-2? May 2020

A signal that things were going to get damp came in the forecasts earlier in the week.

As knowledgeable meteorologists have pointed out it is theoretically wrong to add up these percentiles, but I can't see how else to estimate the event total from available data.

A chronology of musings early in the day of 23 May.

On the morning of 23 May it was evident that bizarreness is going on with rainfall measuring. My weather station has recorded 45 mm of rain in the last 24 hours (to 0500, 23 May). Another station near the Medical Centre has recorded 42 mm to that time. (20.2 mm fell on the 22nd, while 23.8 filled up the gauge before 0500 on the 23rd. Another 4 mm has arrived between 0500 and 0600 on the 23rd.)

BoM, near the airport has recorded 8.2 mm and Gabo Island 28.8.

Looking at the radar image

... suggests that this area is right on the extreme of the rain area, but such a marked difference, for what appears to be steady rain is surprising.

My WS was up to 56.4 mm for the event (36.2 mm since midnight). With a month to date fall of 74.4 mm we are well past the median fall for May (68 mm) and closing in on the mean (80.8 mm).

At around that time  I posted a message on various Facebook groups seeking other people's observations.  We then went for our morning walk walk noting that there was a fair run-off in places.

Reports from elsewhere in Mallacoota

A resident from Betka Rd noted " I was just looking at bomb, thinking noooo way, 13mls, my pond flooded tells me it was a good drop. "

Another resident on Intervale Drive noted 59mm up to 0800.

68 mm at Karbeethong

Later in the day a local identity posted a photo from Bastion Point noting 59 mm which drew a response from near the Narrows of  "We are up to about 70 m l s"

In summary it seems that most people, covering the town area quite well, were recording somewhat over 65 mm.  Or, as expressed to me by a traditionalist, close to 3 inches.

Following up

The rain continued steadily, around 5mm/hr up until about 1400 hrs.

By that time my WS was up to 57.8 mm for the day and the event was  at 81 mm at home.  BoM were still at 29.2mm for the event.

So I took myself for a drive to the mid-West, which in terms of Mallacoota is Betka Beach, Quarry Beach and the Airport.  In effect circling the BoM site.  The beach at Betka was rather damp and the kelp had been hurled up on top of the bar but, despite the helpful surf, it didn't look as though the sea was about to break through.

 Surf was also up a Quarry Beach and there was fair evidence that the Creek beside the car, which drains the paddock in which the BoM site is located had had fair run off.

 On the far side of the Airport a drain was replete.  I think it would have taken more than 28 mm to have achieved that!

 My final stop was at the official depth gauge for the Inlet.  That is currently sitting at 0.46 m. 

It will be interesting to see how far it rises.  Had the rain gone inland and soaked the whole catchment a significant rise might have occurred.  However Bombala AWS had recorded no rain, so I would be surprised if the event causes much of a rise in the level of the Inlet.  A low rise would also be indicted by the steady, soaking nature of the rain.  Excellent for recharging the soil and growing plants!