SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 11 August, 2026 T-index: 40 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 28-32 2E 10 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 13.9 12.5 7.2 SSSMMM BBF%%%... 9.0 8.0 4.3 00 01 15.2 14.4 8.0 ASSXXM MBBBF%%... . 9.7 9.4 4.8 01 02 14.7 15.5 8.6 ASSSXX MBBBP%%%.. .. 9.7 10.2 5.0 02 03 14.0 16.1 8.9 SSSXX MBBPPP%%.. .. 9.6 10.6 5.2 03 04 13.6 16.3 9.0 SSSXX MBBPPP%... . 9.1 10.8 5.2 04 05 13.5 16.1 8.9 SSSXX MBBPPP%... . 8.9 10.7 5.2 05 06 13.1 15.6 8.6 ASSSXX MBBPP%%... . 8.8 10.3 5.0 06 07 13.1 14.5 8.1 ASSSXM MBBP%%.... . 8.7 9.7 4.7 07 08 12.8 12.7 7.3 SSSXMM BB%%%%.... 8.6 8.5 4.2 08 09 12.5 9.5 5.7 SSXMMMM FF%%%%.... 8.6 6.3 3.3 09 10 10.4 2.0 0.0 XMMMMMMMMF %%%..... 7.3 1.4 0.0 10 11 8.3 2.0 0.0 XMMMMMMF%% ..... 5.8 1.4 0.0 11 12 7.3 2.0 0.0 XMMMMMF%%. ... 5.1 1.4 0.0 12 13 6.7 2.0 0.0 XMMMMM%%.. .. 4.7 1.4 0.0 13 14 6.6 2.0 0.0 XMMMMM%%.. .. 4.8 1.4 0.0 14 15 6.4 2.0 0.0 XMMMMF%%.. .. 4.7 1.4 0.0 15 16 6.4 2.0 0.0 XMMMMF%%.. . 4.7 1.4 0.0 16 17 6.3 2.0 0.0 XMMMMF%%.. . 4.7 1.4 0.0 17 18 5.7 2.0 0.0 XMMMM%%%.. . 4.4 1.4 0.0 18 19 5.2 2.0 0.0 XMMMM%%%.. . 3.9 1.4 0.0 19 20 4.6 2.0 0.0 XMMM%%%... 3.4 1.4 0.0 20 21 4.3 2.0 0.0 XMMM%%... 3.3 1.4 0.0 21 22 5.3 2.0 0.0 XMMMM%%.. 4.2 1.4 0.0 22 23 11.1 8.9 5.4 SSMMMFF F%%.. 7.1 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) 11-Aug-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000