SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 18 September, 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 12-16 1E 2 1 5 10 15 20 25 30 35 40 2F 28-34 2E 10 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 16.1 14.0 8.0 ASSXXM MMBBFF%%%. .. 9.8 9.1 4.7 00 01 17.0 15.6 8.8 SSSXX MMBBBF%%%% ... 10.2 10.3 5.2 01 02 17.0 16.6 9.3 SSSSX MMBBBB%%%% ... 10.2 11.0 5.4 02 03 17.1 17.2 9.6 ASSSX XMBBBBB%%% ... 10.3 11.4 5.6 03 04 17.1 17.4 9.7 ASSSX XMBBBBB%%% ... 10.5 11.6 5.6 04 05 16.9 17.3 9.6 ASSSX XMBBBBP%%. ... 10.5 11.5 5.6 05 06 15.8 16.7 9.3 SSSSX XMBBBP%%%. .. 9.9 11.2 5.4 06 07 15.2 15.7 8.9 SSSXX MMBBB%%%.. .. 9.5 10.5 5.1 07 08 15.1 14.2 8.1 ASSSXM MBBBF%%%.. .. 9.4 9.5 4.7 08 09 14.7 11.6 6.9 ASSXMMM MFFF%%%%.. . 9.2 7.7 4.0 09 10 12.5 2.2 0.0 MMMMMMMMMM MF%%%%%... . 8.4 0.0 2.2 10 11 9.8 2.2 0.0 XMMMMMMMM% %%%%...... 6.9 1.5 0.0 11 12 8.7 2.2 0.0 XMMMMMMM%% %%%..... 6.3 1.5 0.0 12 13 8.1 2.2 0.0 XMMMMMMM%% %%..... 5.9 1.5 0.0 13 14 8.0 2.2 0.0 XMMMMMM%%% %.... 5.7 1.5 0.0 14 15 8.4 2.2 0.0 XMMMMMMF%% %.... 5.6 1.5 0.0 15 16 8.0 2.2 0.0 XMMMMMM%%% .... 5.4 1.5 0.0 16 17 7.6 2.2 0.0 XMMMMMF%%% ... 5.3 1.5 0.0 17 18 6.8 2.2 0.0 XMMMMM%%%. .. 5.1 1.5 0.0 18 19 6.2 2.2 0.0 XMMMMM%%.. . 4.5 1.5 0.0 19 20 5.7 2.2 0.0 XMMMM%%... 4.1 1.5 0.0 20 21 5.7 2.2 0.0 XMMMM%%%.. 4.3 1.5 0.0 21 22 8.3 2.2 0.0 XMMMMMMF%% ... 5.6 1.5 0.9 22 23 13.4 11.3 6.7 ASSXMMM BFF%%%.. 8.3 7.2 4.0 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-Sep-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000