Ionospheric Summary and Forecast

Ionospheric Summary

(last updated 05 Jul 2025 23:32 UT)

Date T index 05 Jul 91 Observed Australian Regional MUFs Cocos Island Region: Enhanced by 15% during local day. Depressed by 30% during local night. Niue Island Region: Depressed by 20% during local day. Depressed by 30% during local night. Northern Australian Region: Near predicted monthly values during local day. Depressed by 15% during local night. Depressed by 25% after local dawn. Southern Australian Region: Near predicted monthly values. Antarctic Region (Casey/Davis/Mawson): Depressed by 25% over the UT day. Monthly T index: Month T index Jun 79 Jul 104 Aug 102

Ionospheric Forecast

(last updated 05 Jul 2025 23:32 UT)

Date T index MUFs 06 Jul 90 Depressed 10 to 15%/near predicted monthly values 07 Jul 95 Near predicted monthly values 08 Jul 100 Near predicted monthly values COMMENT: ASWFC Preliminary HF Communications Warning 68 was issued on 4 July and is current for 4-6 Jul. Maximum usable frequencies (MUFs) in the Australian region on UT day 5-Jul were near predicted values to 25% depressed. Conditions at low and high latitudes were degraded during local dawn hours and Cocos Island experienced significant depressions. MUFs are expected to be near predicted values to 15% depressed on UT day 6-Jul, on an improving trend over 7-8 Jul.