SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 30 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 28-32 2E 10 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 17.7 13.1 7.7 ASSXMM MMMFFFF%%% .... 11.2 8.4 4.6 00 01 19.6 15.0 8.6 SSSXM MMMMBFFFF% %%%.... 12.3 9.8 5.1 01 02 20.4 16.2 9.1 SSSSX MMMMMBFFFF %%%%.... 12.7 10.6 5.4 02 03 20.3 16.9 9.5 ASSSX XMMMMBFFFF %%%%.... 12.8 11.1 5.6 03 04 20.2 17.1 9.6 ASSSX XMMMMBBFFF %%%..... 12.6 11.3 5.6 04 05 19.8 16.9 9.5 ASSSX XMMMBBFFF% %%%..... 12.5 11.2 5.5 05 06 19.2 16.3 9.2 SSSSX MMMMBBFFF% %%%..... 12.3 10.8 5.4 06 07 19.3 15.2 8.7 SSSXX MMMMMFFFF% %%%...... 12.4 10.1 5.1 07 08 18.6 13.4 7.8 ASSXMM MMMMFFFF%% %%...... 12.1 8.9 4.5 08 09 17.8 10.0 6.1 ASSMMMM MMMMFFF%%% %...... 11.5 6.7 3.5 09 10 14.0 2.3 0.0 XMMMMMMMMM MFF%%%%%.. .... 9.3 1.5 0.0 10 11 10.7 2.3 0.0 XMMMMMMMMF %%%%%..... . 7.3 1.5 0.0 11 12 9.2 2.3 0.0 XMMMMMMMF% %%...... 6.4 1.5 0.0 12 13 8.1 2.3 0.0 XMMMMMMF%% %..... 5.7 1.5 0.0 13 14 7.8 2.3 0.0 XMMMMMM%%% ..... 5.5 1.5 0.0 14 15 7.5 2.3 0.0 XMMMMMF%%% .... 5.4 1.5 0.0 15 16 7.6 2.3 0.0 XMMMMMF%%% .... 5.4 1.5 0.0 16 17 7.2 2.3 0.0 XMMMMMF%%. ... 5.3 1.5 0.0 17 18 7.0 2.3 0.0 XMMMMM%%%. ... 5.1 1.5 0.0 18 19 6.6 2.3 0.0 XMMMMM%%%. ... 4.6 1.5 0.0 19 20 6.2 2.3 0.0 XMMMMF%%.. .. 4.3 1.5 0.0 20 21 5.6 2.3 0.0 XMMMM%%%.. . 4.1 1.5 0.0 21 22 7.0 2.3 0.0 XMMMMM%%%. . 5.0 1.5 0.0 22 23 14.1 9.4 5.8 ASMMMMM FFFF%%... 8.6 5.4 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) 30-Apr-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000