Ionospheric Summary and Forecast

Ionospheric Summary

(last updated 10 Oct 2026 23:32 UT)

Date T index 10 Oct 37 Observed Australian Regional MUFs Cocos Island Region: No data available during local day. No data available during local night. Niue Island Region: Depressed by 20% during local day. Near predicted monthly values during local night. Depressed by 25% after local dawn. Northern Australian Region: Mostly near predicted monthly values. Depressed by 50% after local dawn. Southern Australian Region: Depressed by 15% during local day. Near predicted monthly values during local night. Depressed by 40% after local dawn. Antarctic Region (Casey/Davis/Mawson): Near predicted monthly values over the UT day. Monthly T index: Month T index Sep 61 Oct 60 Nov 58

Ionospheric Forecast

(last updated 10 Oct 2026 23:32 UT)

Date T index MUFs 11 Oct 20 15 to 40% below predicted monthly values 12 Oct 35 Depressed 15%/near predicted monthly values 13 Oct 35 Depressed 15%/near predicted monthly values COMMENT: ASWFC HF Communications Warning 85 was issued on 10 October and is current for 10-11 Oct. ASWFC SWF HF Communications Warning 86 was issued on 10 October and is current for 10-12 Oct. Maximum Usable Frequencies (MUFs) in the Australian region were near predicted monthly values to 15-50% depressed on UT day 10-Oct. Depressions began following the onset of geomagnetic activity, with MUFs now 40-50% depressed after local dawn. Strong spread F was observed at Hobart during local night hours. MUFs are expected to remain depressed by 15-40% on 11-Oct, and 15% depressed over 12-13 Oct due to forecast geomagnetic activity. Shortwave fadeouts are probable.