SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 20 April, 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 28-32 2E 10 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 17.0 13.3 7.7 ASSXMM MMMFFF%%%% ... 11.0 8.6 4.6 00 01 18.7 15.1 8.6 SSSXM MMMMBFFF%% %%... 11.8 9.9 5.1 01 02 19.8 16.2 9.1 SSSSX MMMMBBFFF% %%%.... 12.1 10.7 5.4 02 03 20.1 16.9 9.4 ASSSX XMMMBBFFFF %%%.... 12.2 11.1 5.5 03 04 20.1 17.1 9.5 ASSSX XMMMBBBFFF %%%..... 12.2 11.3 5.6 04 05 19.8 16.9 9.4 ASSSX XMMMBBFFF% %%%.... 12.2 11.2 5.5 05 06 19.0 16.3 9.1 SSSSX MMMMBBFF%% %%%.... 12.0 10.9 5.3 06 07 18.8 15.3 8.6 ASSSXX MMMMBFFF%% %%%..... 11.9 10.2 5.0 07 08 18.1 13.5 7.8 ASSXXM MMMMFFFF%% %%..... 11.5 9.1 4.5 08 09 17.3 10.4 6.3 ASSMMMM MMMFFFF%%% %..... 11.1 6.9 3.7 09 10 13.7 2.2 0.0 XMMMMMMMMM MMF%%%%%.. .... 9.1 1.5 0.0 10 11 10.0 2.2 0.0 XMMMMMMMM% %%%%...... 7.1 1.5 0.0 11 12 8.8 2.2 0.0 XMMMMMMM%% %%%..... 6.2 1.5 0.0 12 13 7.6 2.2 0.0 XMMMMMM%%% %..... 5.4 1.5 0.0 13 14 7.6 2.2 0.0 XMMMMMM%%% ..... 5.5 1.5 0.0 14 15 7.6 2.2 0.0 XMMMMMM%%% .... 5.4 1.5 0.0 15 16 7.7 2.2 0.0 XMMMMMF%%% .... 5.4 1.5 0.0 16 17 7.4 2.2 0.0 XMMMMMF%%% ... 5.3 1.5 0.0 17 18 7.2 2.2 0.0 XMMMMMF%%% ... 5.2 1.5 0.0 18 19 6.8 2.2 0.0 XMMMMM%%%. ... 4.7 1.5 0.0 19 20 6.3 2.2 0.0 XMMMMF%%.. .. 4.4 1.5 0.0 20 21 5.6 2.2 0.0 XMMMM%%%.. . 4.0 1.5 0.0 21 22 7.0 2.2 0.0 XMMMMM%%%. . 5.1 1.5 0.0 22 23 13.7 9.9 6.0 ASMMMMM FFF%%%... 8.5 6.0 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) 20-Apr-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000