Ionospheric Summary and Forecast

Ionospheric Summary

(last updated 10 Jun 2025 23:30 UT)

Date T index 10 Jun 72 Observed Australian Regional MUFs Cocos Island Region: Near predicted monthly values during local day. Depressed by 25% during local night. Niue Island Region: Depressed by 15% during local day. Depressed by 30% during local night. Northern Australian Region: Near predicted monthly values during local day. Depressed by 30% during local night. Southern Australian Region: Depressed by 15% during local day. Depressed by 30% during local night. Antarctic Region (Casey/Davis/Mawson): Depressed by 20% over the UT day. Frequent sporadic E observed at Mawson and Casey. Monthly T index: Month T index May 94 Jun 109 Jul 107

Ionospheric Forecast

(last updated 10 Jun 2025 23:30 UT)

Date T index MUFs 11 Jun 90 Depressed 10 to 15%/near predicted monthly values 12 Jun 90 Depressed 10 to 15%/near predicted monthly values 13 Jun 90 Depressed 10 to 15%/near predicted monthly values COMMENT: ASWFC HF Communications Warning 61 was issued on 10 June and is current for 10-12 Jun. Maximum usable frequencies (MUFs) in the Australian region on UT day 10-Jun were near predicted values to 30% depressed during local night hours. Depressions of 15% during daylight hours were observed in the southern Australian region. Spread-F was observed at Darwin, Townsville, Hobart and Canberra during local night hours. MUFs in the Australian region over 11-13 Jun are generally expected to be depressed 10-15% to near predicted monthly values. Mildly degraded HF conditions are possible during local night hours. Isolated minor fadeouts are possible.