SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 12 April, 2026 T-index: 75 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 17.6 13.7 8.0 ASSXMM MMMFFFF%%% %... 11.2 8.9 4.7 00 01 19.1 15.5 8.8 SSSXX MMMMBFFFF% %%.... 12.0 10.1 5.2 01 02 20.6 16.6 9.4 ASSSX MMMMMBFFFF %%%%.... 12.4 10.9 5.5 02 03 21.1 17.2 9.7 ASSSX XMMMMBBFFF F%%%.... 12.6 11.4 5.7 03 04 21.3 17.4 9.8 ASSSX XMMMMBBFFF F%%%.... 12.6 11.6 5.7 04 05 21.0 17.3 9.7 ASSSX XMMMMBBFFF %%%%.... 12.8 11.5 5.6 05 06 19.9 16.7 9.4 ASSSX XMMMMBFFF% %%%.... 12.2 11.1 5.5 06 07 19.4 15.6 8.9 SSSXX MMMMMFFFF% %%%%.... 11.9 10.4 5.2 07 08 18.6 13.9 8.1 ASSSXM MMMMFFFF%% %%%.... 11.4 9.3 4.7 08 09 18.1 11.0 6.6 ASSXMMM MMMMFFFF%% %%.... 11.2 7.3 3.9 09 10 14.8 2.3 0.0 XMMMMMMMMM MMFF%%%%%% ..... 9.6 1.5 0.0 10 11 10.8 2.3 0.0 XMMMMMMMMM %%%%%%.... .. 7.6 1.5 0.0 11 12 9.5 2.3 0.0 XMMMMMMMM% %%%%...... 6.7 1.5 0.0 12 13 8.3 2.3 0.0 XMMMMMMM%% %%..... 5.9 1.5 0.0 13 14 8.3 2.3 0.0 XMMMMMMF%% %..... 5.8 1.5 0.0 14 15 8.4 2.3 0.0 XMMMMMMF%% %.... 5.8 1.5 0.0 15 16 8.3 2.3 0.0 XMMMMMMF%% %.... 5.7 1.5 0.0 16 17 8.0 2.3 0.0 XMMMMMM%%% .... 5.6 1.5 0.0 17 18 7.8 2.3 0.0 XMMMMMM%%% .... 5.5 1.5 0.0 18 19 7.2 2.3 0.0 XMMMMMF%%% ... 5.0 1.5 0.0 19 20 6.5 2.3 0.0 XMMMMM%%%. .. 4.6 1.5 0.0 20 21 5.8 2.3 0.0 XMMMM%%%.. . 4.1 1.5 0.0 21 22 7.5 2.3 0.0 XMMMMMF%%. .. 5.4 1.5 0.0 22 23 14.3 10.5 6.4 ASSMMMM FFFF%%%.. 8.8 6.5 3.9 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) 12-Apr-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000