SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 13 August, 2026 T-index: 60 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 15.1 12.9 7.5 ASSXMM MBFFF%%... . 9.5 8.3 4.5 00 01 16.7 14.8 8.4 ASSSXM MMBBFF%%%. ... 10.4 9.6 5.0 01 02 16.5 15.9 8.9 SSSXX MMBBBF%%%% .... 10.5 10.5 5.3 02 03 16.2 16.6 9.2 SSSSX MMBBBB%%%% .... 10.6 10.9 5.4 03 04 15.5 16.8 9.3 ASSSX XMBBBP%%%. ... 10.2 11.1 5.5 04 05 15.2 16.6 9.2 SSSSX MMBBBP%%.. ... 10.0 11.0 5.4 05 06 14.8 16.0 8.9 SSSXX MMBBPP%%.. ... 9.7 10.6 5.2 06 07 14.6 14.9 8.4 ASSSXM MBBB%%%%.. ... 9.6 9.9 4.9 07 08 14.2 13.1 7.6 SSSXMM MBBF%%%... .. 9.5 8.8 4.4 08 09 14.1 9.8 6.0 ASXMMMM MFFF%%%... .. 9.5 6.6 3.5 09 10 11.8 2.2 0.0 XMMMMMMMMM F%%%%..... 8.1 1.5 0.0 10 11 9.2 2.2 0.0 XMMMMMMMF% %%..... 6.4 1.5 0.0 11 12 8.0 2.2 0.0 XMMMMMM%%% ..... 5.6 1.5 0.0 12 13 7.3 2.2 0.0 XMMMMMF%%. .... 5.1 1.5 0.0 13 14 7.0 2.2 0.0 XMMMMM%%%. ... 5.0 1.5 0.0 14 15 6.7 2.2 0.0 XMMMMM%%%. .. 4.9 1.5 0.0 15 16 6.5 2.2 0.0 XMMMMM%%%. .. 4.8 1.5 0.0 16 17 6.4 2.2 0.0 XMMMMM%%.. .. 4.8 1.5 0.0 17 18 6.0 2.2 0.0 XMMMMM%%.. .. 4.6 1.5 0.0 18 19 5.7 2.2 0.0 XMMMM%%%.. .. 4.2 1.5 0.0 19 20 5.1 2.2 0.0 XMMMM%%... . 3.7 1.5 0.0 20 21 4.6 2.2 0.0 XMMMM%%... 3.6 1.5 0.0 21 22 5.7 2.2 0.0 XMMMM%%... 4.3 1.5 0.0 22 23 12.0 9.3 5.7 ASMMMBF F%%%... 7.5 5.3 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) 13-Aug-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000