SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 18 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 13.1 7.6 ASSXMM MBBFF%%... . 9.6 8.4 4.5 00 01 16.6 14.9 8.4 ASSSXM MMBBFF%%%. ... 10.5 9.7 5.0 01 02 16.6 16.0 9.0 SSSXX MMBBBB%%%% .... 10.5 10.5 5.3 02 03 16.2 16.7 9.3 SSSSX MMBBBB%%%% .... 10.6 11.0 5.4 03 04 15.6 16.9 9.4 ASSSX XMBBBP%%%. ... 10.3 11.2 5.5 04 05 15.3 16.7 9.3 SSSSX XMBBBP%%%. ... 10.1 11.1 5.4 05 06 14.9 16.1 9.0 SSSXX MMBBPP%%.. ... 9.8 10.7 5.3 06 07 14.6 15.0 8.5 ASSSXM MBBBP%%%.. ... 9.6 10.0 5.0 07 08 14.3 13.3 7.7 SSSXMM MBBF%%%... .. 9.5 8.9 4.4 08 09 14.2 10.1 6.1 ASSMMMM MFFF%%%... .. 9.5 6.7 3.5 09 10 11.9 2.2 0.0 XMMMMMMMMM F%%%%..... 8.1 1.5 0.0 10 11 9.4 2.2 0.0 XMMMMMMMF% %%..... 6.5 1.5 0.0 11 12 8.2 2.2 0.0 XMMMMMMF%% %.... 5.7 1.5 0.0 12 13 7.5 2.2 0.0 XMMMMMF%%% .... 5.2 1.5 0.0 13 14 7.2 2.2 0.0 XMMMMMF%%. ... 5.2 1.5 0.0 14 15 6.9 2.2 0.0 XMMMMM%%%. ... 5.0 1.5 0.0 15 16 6.7 2.2 0.0 XMMMMM%%%. .. 4.9 1.5 0.0 16 17 6.6 2.2 0.0 XMMMMM%%%. .. 4.9 1.5 0.0 17 18 6.1 2.2 0.0 XMMMMM%%.. .. 4.7 1.5 0.0 18 19 5.7 2.2 0.0 XMMMMM%%.. .. 4.2 1.5 0.0 19 20 5.1 2.2 0.0 XMMMM%%... . 3.7 1.5 0.0 20 21 4.7 2.2 0.0 XMMMM%%... 3.6 1.5 0.0 21 22 5.8 2.2 0.0 XMMMM%%... 4.4 1.5 0.0 22 23 12.1 9.6 5.8 ASMMMMF FF%%... 7.7 5.7 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) 18-Aug-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000