Uncertainty in hydraulics, hydrology and meteorology
With Queensland right in the middle of storm season it’s good to consider the typical accuracies within our flood predictions. Whilst our hydraulic engineers want an accuracy of ±10% from their flood models, several days out from the event our hydrologists think a reasonable flow forecast should be within ±50%. But it not until we talk to our meteorologists that we start to understand we aren’t really sure if a storm will even be here!
Our meteorologist Kat put this summary together of the different weather models this morning for TC Oma. Still no certainty whether the system will visit Australia or New Zealand.
GFS - The system is closest tracking point to the QLD coastline Thursday night (21st Feb) at 160E before being quickly entangled in an upper level trough and hitting New Zealand
ECMWF – Shows TC OMA tracking WSW with the very outer edges of the system reaching the Fraser Coast on Saturday night (23rd), before turning towards the Coral Sea
ACCESS – Shows OMA stalling at about 160E between Thursday and Sunday, causing it to weaken and slowly and shift towards the Coral Sea
Weatherzone WRF – Weakening over the next two days, before re-strengthening with a westerly track and reaching the Fraser Coast on Sunday 24th.