Failed Forecast 21st January 2014


Fairly deep moist layer


Moisture depth decreased in this model run.

The models, and models they are, were pointing to fairly impressive soundings in the region particularly near Port Macquarie. Taking the upper and lower limits, the CAPE and CIN values were pointing to a fairly substantial and easily breaking CAPE values in excess of 3000J/kg and CIN values of the 20 mark even as early as 2pm. There was a 20% value of fail mode based on the sensitivity of moisture plugging in the worst possible scenario. And the fail occurred. The region near Mt Seaview or jut south did receive and shower and  a storm to the north but it was NE NSW that received severe warnings for hail and wind. The day promised a low base scenario and deep ample moisture. So what went wrong?

Anticipated values of Surface Lifted Index - the region near Port Macquarie was where the soundings were taken above.


Anticipated CAPE values in the Port Macquarie region



Total Totals shifted out of the area in latter Bureau model run probably due to upper level warming.


Soundings in NE NSW with high CIN values - higher based convection eventuated.


fairly substantial heating over NE NSW

It seems the latter Bureau models put the temperatures at 500hPa of -6C which to me introduced substantial warming compared to the -8C. This meant that towers that did rise rapidly and only filtered through this layer quickly disconnecting from the anvils. There also seemed to be a lack of lower level forcing.

4 thoughts on “Failed Forecast 21st January 2014

Leave a Reply