Ionospheric Summary and Forecast

Ionospheric Summary

(last updated 14 Apr 2025 23:31 UT)

Date T index 14 Apr 116 Observed Australian Regional MUFs Cocos Island Region: Enhanced by 25% during local day. Enhanced by 45% during local night. Niue Island Region: Enhanced by 30% during local day. Near predicted monthly values during local night. Enhanced by 20% after local dawn. Northern Australian Region: Near predicted monthly values. Southern Australian Region: Near predicted monthly values during local day. Southeast depressed by 25% during local night. Antarctic Region (Casey/Davis/Mawson): Depressed by 20% over the UT day. Monthly T index: Month T index Mar 126 Apr 115 May 113

Ionospheric Forecast

(last updated 14 Apr 2025 23:31 UT)

Date T index MUFs 15 Apr 120 Near predicted monthly values/depressed 5 to 15% 16 Apr 75 Depressed 15 to 20%/near predicted monthly values 17 Apr 95 Depressed 10 to 15%/near predicted monthly values COMMENT: ASWFC SWF HF Communications Warning 37 was issued on 14 April and is current for 14-15 Apr. Maximum usable frequencies (MUFs) in the Australian region on UT day 14-Apr were generally near predicted values with depressions of 25% observed during local night hours for the southeast Australian region. Spread-F was observed during local night hours at Hobart. MUFs are expected to be initially near predicted monthly values on 15-Apr, with depressed conditions possible late in the UT day for the southern Australian region. Southern Australian region MUFs are expected to be depressed 15-20% on 16-Apr if CME induced geomagnetic storm activity eventuates late in the UT day on 15-Apr.