SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 17 April, 2026 T-index: 70 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 17.5 13.5 7.8 ASSXMM MMMFFFF%%% .... 11.1 8.7 4.7 00 01 19.0 15.3 8.7 SSSXM MMMMBFFF%% %%.... 11.9 10.0 5.1 01 02 20.6 16.4 9.2 SSSSX MMMMMBFFFF %%%%.... 12.4 10.8 5.4 02 03 20.8 17.0 9.5 ASSSX XMMMMBBFFF %%%%.... 12.6 11.2 5.6 03 04 20.9 17.2 9.6 ASSSX XMMMMBBFFF %%%%.... 12.6 11.4 5.6 04 05 20.6 17.1 9.5 ASSSX XMMMMBBFFF %%%%... 12.7 11.3 5.6 05 06 19.5 16.5 9.3 SSSSX MMMMMBFFF% %%%.... 12.2 11.0 5.4 06 07 19.3 15.4 8.8 SSSXX MMMMMFFFF% %%%%.... 12.0 10.3 5.1 07 08 18.4 13.7 7.9 ASSXXM MMMMFFFF%% %%..... 11.5 9.2 4.6 08 09 17.8 10.7 6.4 ASSXMMM MMMMFFF%%% %%.... 11.2 7.1 3.8 09 10 14.2 2.3 0.0 XMMMMMMMMM MMFF%%%%%. ..... 9.5 1.5 0.0 10 11 10.4 2.3 0.0 XMMMMMMMMM %%%%%..... . 7.4 1.5 0.0 11 12 9.2 2.3 0.0 XMMMMMMMF% %%%...... 6.5 1.5 0.0 12 13 8.0 2.3 0.0 XMMMMMM%%% %..... 5.7 1.5 0.0 13 14 7.9 2.3 0.0 XMMMMMM%%% %.... 5.7 1.5 0.0 14 15 8.0 2.3 0.0 XMMMMMM%%% .... 5.6 1.5 0.0 15 16 8.0 2.3 0.0 XMMMMMM%%% .... 5.5 1.5 0.0 16 17 7.6 2.3 0.0 XMMMMMM%%% .... 5.5 1.5 0.0 17 18 7.5 2.3 0.0 XMMMMMM%%% .... 5.4 1.5 0.0 18 19 7.0 2.3 0.0 XMMMMM%%%. ... 4.8 1.5 0.0 19 20 6.4 2.3 0.0 XMMMMM%%%. .. 4.5 1.5 0.0 20 21 5.7 2.3 0.0 XMMMM%%%.. . 4.0 1.5 0.0 21 22 7.2 2.3 0.0 XMMMMMF%%. . 5.2 1.5 0.0 22 23 14.1 10.2 6.2 ASSMMMM FFFF%%... 8.6 6.2 3.8 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) 17-Apr-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000