Solar flare activity on UT day 16-Sep is expected to be at the R0 level. S0 solar radiation storm conditions are expected. The solar wind is expected to be moderate to strong. G1 geomagnetic conditions are expected, with a chance of G2. HF radio propagation conditions may become mildly degraded upon the onset of geomagnetic activity. Maximum usable frequencies in the Australian region are expected to be near predicted monthly values to depressed by up to 15%.