SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 18 July, 2026 T-index: 55 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 14.5 12.1 7.0 SSXMMM BBFF%%%... 9.2 7.6 4.3 00 01 16.1 14.2 8.0 ASSXXM MBBBFF%%.. .. 10.2 9.2 4.8 01 02 15.7 15.4 8.6 SSSXX MMBBB%%%%. ... 10.3 10.1 5.1 02 03 15.2 16.0 8.9 SSSXX MMBBBP%%%. ... 10.3 10.5 5.2 03 04 14.4 16.3 9.0 SSSXX MMBBPP%%.. .. 9.7 10.7 5.3 04 05 14.3 16.1 8.9 SSSXX MBBBPP%%.. .. 9.5 10.6 5.2 05 06 13.9 15.4 8.6 ASSSXX MBBPP%%... .. 9.3 10.2 5.0 06 07 13.8 14.3 8.1 ASSSXM MBBP%%%... .. 9.1 9.5 4.7 07 08 13.6 12.4 7.2 SSSXMM MBF%%%%... .. 9.1 8.2 4.2 08 09 13.2 8.4 5.2 ASSMMMMM MFF%%%.... . 9.0 5.6 3.0 09 10 10.2 2.2 0.0 XMMMMMMMFF %%%..... 7.2 1.4 0.0 10 11 7.9 2.2 0.0 XMMMMMM%%% ..... 5.7 1.4 0.0 11 12 6.9 2.2 0.0 XMMMMM%%%. ... 5.0 1.4 0.0 12 13 6.4 2.2 0.0 XMMMMF%%.. .. 4.6 1.4 0.0 13 14 6.1 2.2 0.0 XMMMMF%%.. . 4.5 1.4 0.0 14 15 6.0 2.2 0.0 XMMMM%%%.. . 4.5 1.4 0.0 15 16 6.1 2.2 0.0 XMMMMF%%.. . 4.5 1.4 0.0 16 17 5.8 2.2 0.0 XMMMM%%%.. . 4.5 1.4 0.0 17 18 5.4 2.2 0.0 XMMMM%%... . 4.1 1.4 0.0 18 19 5.1 2.2 0.0 XMMMM%%... . 3.8 1.4 0.0 19 20 4.7 2.2 0.0 XMMM%%%... 3.3 1.4 0.0 20 21 4.6 2.2 0.0 XMMM%%%... 3.3 1.4 0.0 21 22 5.6 2.2 0.0 XMMMM%%... 4.3 1.4 0.0 22 23 10.7 7.6 4.8 SMMMFFF %%... 6.6 0.0 3.2 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) 18-Jul-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000