Ionospheric Summary and Forecast

Ionospheric Summary

(last updated 12 Oct 2025 23:30 UT)

Date T index 12 Oct 71 Observed Australian Regional MUFs Cocos Island Region: Near predicted monthly values. Niue Island Region: Near predicted monthly values during local day. Depressed by 15% during local night. Northern Australian Region: Near predicted monthly values. Southern Australian Region: Depressed by 25% during local day. Near predicted monthly values during local night. Antarctic Region (Casey/Davis/Mawson): Depressed by 15% over the UT day. Monthly T index: Month T index Sep 109 Oct 89 Nov 89

Ionospheric Forecast

(last updated 12 Oct 2025 23:30 UT)

Date T index MUFs 13 Oct 80 Southern Australian region 15-25% depressed 14 Oct 105 Near predicted monthly values 15 Oct 100 Near predicted monthly values COMMENT: ASWFC HF Communications Warning 92 was issued on 12 October and is current for 12-13 Oct. Maximum usable frequencies (MUFs) in the northern Australian region on UT day 12-Oct were near predicted monthly values. Southern Australian region MUFs were near predicted monthly values to 25% depressed during local day. Southern Australian region MUFs are expected to be 15-25% depressed on 13-Oct with northern Australian region MUFs generally expected to remain near predicted monthly values. MUFs are expected to be near predicted monthly values over 14-15 Oct. Shortwave fadeouts are possible.