THE CYCLONE.

Inquiry:

The Meteorological Bureau telegraphed Flat-top on the 23rd that cyclonic conditions prevailed between Mackay and Townsville. This was signalled to the s.s. " Cooma " from Flat-top; but, unfortunately, the "Yongala" had left some hours previously.

"The Cooma was a little late arriving there, 

and at dusk they were informed on board 

by signal that a cyclone was reported 

north-east of Bowen. Captain Smith decided 

to go into Mackay Harbor. Later on driving rain 

fell heavily, and although one attempt was

made to get out, the vessel could not do

so, owing to the weather closing in again."

However, and this is a big however:

The Argus, Melbourne, 24 March, 1911.

THE WEATHER

OFFICIAL FORECAST

Forecast by the Commonwealth Meteorologist

Mr. H. A. Hunt, Thursday 9 pm. (23 March)

"Fine throughout, some cloud in southern districts

and one or two misty showers along the coast. 

Variable winds tending east and northeast."

Queensland: cloudy with further rains along

seaboard: unsettled along Peninsular, with 

probability of stormy weather with heavy falls.

Fine inland, with moderate temperatures;

southeasterly winds.

There is a disconnect between that which was reported at the Inquiry and the official forecast printed in the press. In the latter, there was NO reference to a cyclone. Perhaps the signal the captain of the Cooma received was a local report from Cape Bowling Green Light? It seems disingenuous for the Bureau to be claiming 'a job well done'. Also, these warnings only served a purpose if they could be timeously issued to masters. Both Yongala and Grantala had sailed.

The s.s. " Taiyuan " anchored at Repulse Island on the morning of the 23rd, and had the wind from S.E. (strong gale with occasional terrific squalls). At Dent Island it also blew from S.E., force 7 to 9, with no indication of a cyclone, when the " Yongala" passed at 6.30 p.m.

It is no surprise that Yongala could maintain 17 knots with such a tail wind.

At Cape Bowling Green, however, the wind commenced at S.S.E., veering to S., S.W., W., and thence to N.W. The "Grantala," bound South, anchored about 7 miles W.N.W. from the Cape, experienced the same weather conditions; barometer 29.50, which would place her on the northern margin of the right-hand semicircle of the storm proving unerringly that in conformity with the laws relating to hurricanes in the Southern Hemisphere it came from the N.E., and in its progressive motion to the S.W. (inland) large trees were uprooted, clearing a well-defined space through the forest at the back of Cape Upstart. 

It would have been helpful to establish what the original barometer readings were prior to 29.50 and then calculate whether the drop was significant enough to alert Captain Knight.

From the scant data available, it may be assumed that the diameter of the storm did not exceed 30 miles; and as the course of the " Yongala " would be nearly at right angles with the path of the storm, it is just possible that she reached its southern margin, about midnight, between Cape Upstart and Cape Bowling Green.

I believe that much of the Yongala disaster hinged on the absence of a cyclone warning and the actions taken by Captain Knight. It is claimed that Captain Knight departed Flat-top anchorage 1.40 pm, 23 March, before cyclone warnings were issued, but given the above there does not appear to have been an official cyclone warning at all.

The SS Taiyuan anchored at Repulse Island during the morning of 23 March due to a 'strong gale with occasional terrific squalls'. See image below, Repulse Islands are roughly 37 n miles from Mackay. Surely Captain Knight was aware of the conditions into which he steamed unless he assumed that the gale coming from the southeast represented a front moving up the coast, and one he could outrun going north, if he 'put his foot down'.

A tropical cyclone off the east coast of Australia is characterised by a low pressure centre creating gales and flooding rain. Such a cyclone would approach from the northeast which might suggest why the Taiyuan anchored and at Flat-top (Mackay) there were no signs of the approaching cyclone until much later.

We know that the worst of the cyclone was experienced between 11 pm, 23 March and 3 am 24 March (Captain Sim, Grantala). 30 n miles diameter of the cyclone also suggests that it was limited in its path of destruction and could not have extended from Cape Bowling Green to Mackay.

However, there are certain tell-tale signs as to the approach of a cyclone. 12 hours before a cyclone strikes rain squalls are more frequent, winds do not lessen, the cloud ceiling lowers and the barometer is falling at 1 millibar per hour. 

As Yongala progressed into the cyclone zone, Captain Knight passing Dent Island would have been aware of the barometer dropping and a southeasterly gale strong enough to prevent standing unsupported on deck. But there again he could still have been under the impression the system was coming from behind.

Once into the system he would have been past the point of return and been little choice but to plow through.

According to:

http://www.aicomos.com/wp-content/uploads/vidukayongala.pdf

cyclones in the Townsville region are generally from northwest to southeast.