SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 12 August, 2026 T-index: 35 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 27-32 2E 10 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 13.8 12.5 7.1 SSSMMM BBF%%%... 8.8 8.0 4.3 00 01 15.0 14.3 8.0 ASSXXM MBBB%%%... . 9.5 9.3 4.7 01 02 14.5 15.4 8.5 ASSSXX MBBBP%%... . 9.5 10.1 5.0 02 03 13.7 16.0 8.8 SSSXX MBBPPP%%.. .. 9.4 10.6 5.2 03 04 13.6 16.2 8.9 SSSXX MBBPPP%... . 8.9 10.7 5.2 04 05 13.4 16.1 8.8 SSSXX MBBPPP%... 8.8 10.6 5.1 05 06 12.9 15.5 8.5 ASSSXX MBPPP%.... 8.6 10.3 5.0 06 07 12.7 14.4 8.0 ASSXXM BBPP%%.... . 8.5 9.6 4.7 07 08 12.3 12.7 7.2 SSSXMM BB%%%%.... 8.3 8.5 4.2 08 09 12.0 9.5 5.7 SSXMMMM F%%%%.... 8.3 6.3 3.3 09 10 10.1 2.0 0.0 XMMMMMMMFF %%%.... 7.2 1.3 0.0 10 11 8.0 2.0 0.0 XMMMMMM%%% .... 5.7 1.3 0.0 11 12 7.1 2.0 0.0 XMMMMMF%%. ... 5.0 1.3 0.0 12 13 6.5 2.0 0.0 XMMMMF%%.. .. 4.7 1.3 0.0 13 14 6.5 2.0 0.0 XMMMMM%%.. .. 4.8 1.3 0.0 14 15 6.4 2.0 0.0 XMMMMF%%.. .. 4.6 1.3 0.0 15 16 6.3 2.0 0.0 XMMMMF%%.. . 4.6 1.3 0.0 16 17 6.2 2.0 0.0 XMMMMF%%.. . 4.6 1.3 0.0 17 18 5.7 2.0 0.0 XMMMM%%%.. . 4.3 1.3 0.0 18 19 5.1 2.0 0.0 XMMMM%%%.. . 3.8 1.3 0.0 19 20 4.6 2.0 0.0 XMMM%%%... 3.3 1.3 0.0 20 21 4.2 2.0 0.0 XMMM%%... 3.2 1.3 0.0 21 22 5.3 2.0 0.0 XMMMM%%.. 4.2 1.3 0.0 22 23 11.0 8.9 5.4 SSMMMFF %%... 7.0 5.1 3.4 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) 12-Aug-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000