SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 4 August, 2026 T-index: 80 Bearings: 201 24 Distance: 1680 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 12-15 1E 2 1 5 10 15 20 25 30 35 40 2F 28-33 2E 10 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 15.9 12.9 7.6 ASSXMM MBFFF%%%.. .. 10.0 8.2 4.6 00 01 17.9 14.9 8.6 SSSXM MMMBFFF%%% %.... 11.2 9.7 5.1 01 02 18.0 16.1 9.1 SSSSX MMMBBBF%%% %..... 11.5 10.6 5.4 02 03 18.0 16.8 9.4 ASSSX XMMBBBF%%% %..... 11.6 11.1 5.6 03 04 17.1 17.0 9.6 ASSSX XMMBBBB%%% ..... 11.1 11.3 5.6 04 05 16.8 16.8 9.5 ASSSX XMBBBB%%%% .... 10.9 11.2 5.5 05 06 16.0 16.2 9.2 SSSSX MMBBBP%%%. .... 10.5 10.8 5.4 06 07 15.8 15.1 8.6 ASSSXM MMBBB%%%%. .... 10.3 10.0 5.0 07 08 15.6 13.2 7.7 ASSXMM MMBFF%%%%. .... 10.3 8.8 4.5 08 09 15.6 9.6 5.9 SSXMMMM MMFFF%%%%. .... 10.3 6.4 3.4 09 10 12.7 2.3 0.0 XMMMMMMMMM FF%%%%.... . 8.7 1.5 0.0 10 11 9.8 2.3 0.0 XMMMMMMMF% %%%..... 6.9 1.5 0.0 11 12 8.4 2.3 0.0 XMMMMMMF%% %..... 5.9 1.5 0.0 12 13 7.6 2.3 0.0 XMMMMMF%%% .... 5.4 1.5 0.0 13 14 7.1 2.3 0.0 XMMMMMF%%. ... 5.2 1.5 0.0 14 15 6.7 2.3 0.0 XMMMMM%%%. .. 4.9 1.5 0.0 15 16 6.5 2.3 0.0 XMMMMM%%%. .. 4.9 1.5 0.0 16 17 6.4 2.3 0.0 XMMMMM%%.. .. 4.8 1.5 0.0 17 18 6.1 2.3 0.0 XMMMMM%%.. .. 4.6 1.5 0.0 18 19 5.8 2.3 0.0 XMMMMM%%.. .. 4.3 1.5 0.0 19 20 5.2 2.3 0.0 XMMMM%%... . 3.8 1.5 0.0 20 21 4.9 2.3 0.0 XMMMM%%... 3.7 1.5 0.0 21 22 6.0 2.3 0.0 XMMMM%%... 4.4 1.5 0.0 22 23 12.2 8.9 5.6 ASMMMFF FF%%... 7.5 4.8 3.6 23 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT =============================================================================== |. USABLE LESS THAN 50% OF DAYS |% USABLE 50% TO 90% OF DAYS | |B BOTH E and F MODES 90% OF DAYS |M MIXED FIRST AND SECOND F MODES | |F FIRST F MODE ONLY |E E-LAYER PROPAGATION |P 90% E and 50-90% F | |S SECOND MODES ONLY |A HIGH ABSORPTION |X COMPLEX MODES | (c) 4-Aug-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000