Ionospheric Summary and Forecast

Ionospheric Summary

(last updated 07 Dec 2025 23:30 UT)

Date T index 07 Dec 146 Observed Australian Regional MUFs Cocos Island Region: Near predicted monthly values during local day. Enhanced by 15% during local night. Enhanced by 25% after local dawn. Niue Island Region: Enhanced by 40% during local day. Enhanced by 75% during local night. Enhanced by 30% after local dawn. Northern Australian Region: Enhanced by 15% during local day. Enhanced by 30% during local night. Southern Australian Region: Near predicted monthly values during local day. Enhanced by 15% 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 07 Dec 2025 23:30 UT)

Date T index MUFs 08 Dec 130 Near predicted monthly values to 20% enhanced 09 Dec 90 Near predicted monthly values to 20% depressed 10 Dec 100 Near predicted monthly values to 20% depressed COMMENT: ASWFC Preliminary HF Communications Warning 117 was issued on 6 December and is current for 9-10 Dec. ASWFC SWF HF Communications Warning 118 was issued on 7 December and is current for 7-8 Dec. Maximum usable frequencies (MUFs) in the Australian region on UT day 7-Dec were near predicted values to 30% enhanced. Sporadic-E was observed in Niue, Norfolk Island and Hobart during local night hours. MUFs are expected to be enhanced by 20% on UT day 8-Dec, but likely to trend down to near predicted values on 9-Dec. Depressions of 20% may begin by local night hours on 9-Dec and into 10-Dec. Nighttime sporadic-E is expected.