SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 19 August, 2026 T-index: 65 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 15.5 13.2 7.6 ASSXMM MBBFF%%%.. . 9.8 8.5 4.6 00 01 17.0 15.0 8.5 ASSSXM MMBBBF%%%% .... 10.7 9.8 5.0 01 02 16.9 16.2 9.1 SSSSX MMBBBB%%%% .... 10.7 10.6 5.3 02 03 16.8 16.8 9.4 ASSSX XMBBBB%%%% ..... 10.8 11.1 5.5 03 04 16.1 17.0 9.5 ASSSX XMBBBBP%%. .... 10.5 11.3 5.5 04 05 15.8 16.8 9.4 ASSSX XMBBBP%%%. ... 10.3 11.2 5.5 05 06 15.2 16.2 9.1 SSSSX MMBBBP%%.. ... 10.0 10.8 5.3 06 07 14.9 15.2 8.6 ASSSXX MMBBP%%%.. ... 9.8 10.1 5.0 07 08 14.6 13.4 7.8 ASSXMM MBBF%%%%.. ... 9.7 9.0 4.5 08 09 14.5 10.2 6.2 ASSMMMM MFFF%%%%.. ... 9.7 6.8 3.6 09 10 12.2 2.2 0.0 XMMMMMMMMM FF%%%..... . 8.3 1.5 0.0 10 11 9.6 2.2 0.0 XMMMMMMMF% %%%..... 6.7 1.5 0.0 11 12 8.4 2.2 0.0 XMMMMMMF%% %..... 5.8 1.5 0.0 12 13 7.7 2.2 0.0 XMMMMMF%%% .... 5.4 1.5 0.0 13 14 7.3 2.2 0.0 XMMMMMF%%% .... 5.2 1.5 0.0 14 15 7.1 2.2 0.0 XMMMMMF%%. ... 5.0 1.5 0.0 15 16 6.9 2.2 0.0 XMMMMM%%%. ... 4.9 1.5 0.0 16 17 6.7 2.2 0.0 XMMMMM%%%. .. 4.8 1.5 0.0 17 18 6.3 2.2 0.0 XMMMMM%%%. .. 4.8 1.5 0.0 18 19 5.9 2.2 0.0 XMMMMM%%.. .. 4.3 1.5 0.0 19 20 5.3 2.2 0.0 XMMMM%%... . 3.8 1.5 0.0 20 21 4.9 2.2 0.0 XMMMM%%... 3.7 1.5 0.0 21 22 6.0 2.2 0.0 XMMMM%%%.. 4.5 1.5 0.0 22 23 12.4 9.7 5.9 ASMMMMF FF%%... 7.8 5.7 3.7 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) 19-Aug-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000