Ionospheric Summary and Forecast

Ionospheric Summary

(last updated 29 Dec 2025 23:30 UT)

Date T index 29 Dec 120 Observed Australian Regional MUFs Cocos Island Region: No data available during local day. No data available during local night. Niue Island Region: Mostly near predicted monthly values. Enhanced by 20% after local dawn. Northern Australian Region: Near predicted monthly values during local day. Enhanced by 15% during local night. Enhanced by 20% after local dawn. Southern Australian Region: Near predicted monthly values during local day. Enhanced by 20% during local night. Antarctic Region (Casey/Davis/Mawson): Near predicted monthly values over the UT day. Monthly T index: Month T index Nov 103 Dec 89 Jan 89

Ionospheric Forecast

(last updated 29 Dec 2025 23:30 UT)

Date T index MUFs 30 Dec 110 Near predicted monthly values 31 Dec 90 Near predicted values 01 Jan 90 Near predicted monthly values to 15% depressed COMMENT: ASWFC Preliminary HF Communications Warning 125 was issued on 29 December and is current for 31 Dec to 1 Jan. Maximum usable frequencies (MUFs) in the Australian region on UT day 29-Dec were near predicted values to 20% enhanced. Sporadic-E was prominent along the east coast, particularly in Norfolk Island and in Brisbane. MUFs are expected to remain enhanced until 31-Dec, when they are likely to trend to baseline predicted values. Depressions up to 15% are possible on 1-Jan.