SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 14 April, 2026 T-index: 80 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 18.2 13.7 8.0 ASSXMM MMMFFFFF%% %... 11.6 8.9 4.8 00 01 19.8 15.5 8.9 SSSXX MMMMBFFFF% %%%... 12.4 10.2 5.2 01 02 21.4 16.7 9.4 ASSSX MMMMMBFFFF F%%%%... 12.8 11.0 5.5 02 03 21.9 17.3 9.7 ASSSX XMMMMBBFFF F%%%%.... 12.9 11.4 5.7 03 04 22.1 17.5 9.8 ASSSX XMMMMBBFFF FF%%%.... 12.9 11.6 5.7 04 05 21.8 17.3 9.7 ASSSX XMMMMBBFFF F%%%.... 13.0 11.5 5.7 05 06 20.5 16.7 9.5 ASSSX XMMMMBFFFF %%%%.... 12.6 11.1 5.5 06 07 20.0 15.7 9.0 SSSXX MMMMMFFFF% %%%%..... 12.3 10.5 5.2 07 08 19.2 13.9 8.1 ASSSXM MMMMFFFFF% %%%.... 11.8 9.4 4.7 08 09 18.7 10.9 6.6 ASSXMMM MMMMFFFF%% %%%.... 11.6 7.3 3.9 09 10 15.3 2.3 0.0 XMMMMMMMMM MMMFF%%%%% ...... 9.9 1.5 0.0 10 11 11.4 2.3 0.0 XMMMMMMMMM F%%%%%.... .. 7.8 1.5 0.0 11 12 10.1 2.3 0.0 XMMMMMMMMF %%%%...... 7.0 1.5 0.0 12 13 8.7 2.3 0.0 XMMMMMMM%% %%..... 6.2 1.5 0.0 13 14 8.5 2.3 0.0 XMMMMMMF%% %%.... 6.0 1.5 0.0 14 15 8.6 2.3 0.0 XMMMMMMF%% %.... 5.9 1.5 0.0 15 16 8.6 2.3 0.0 XMMMMMMF%% %.... 5.8 1.5 0.0 16 17 8.2 2.3 0.0 XMMMMMMF%% %.... 5.7 1.5 0.0 17 18 7.9 2.3 0.0 XMMMMMM%%% .... 5.6 1.5 0.0 18 19 7.3 2.3 0.0 XMMMMMF%%% ... 5.0 1.5 0.0 19 20 6.6 2.3 0.0 XMMMMM%%%. .. 4.6 1.5 0.0 20 21 5.9 2.3 0.0 XMMMM%%%.. . 4.2 1.5 0.0 21 22 7.6 2.3 0.0 XMMMMMF%%. .. 5.5 1.5 0.0 22 23 14.8 10.5 6.4 ASSMMMM FFFF%%%... 9.0 6.4 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) 14-Apr-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000