SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 19 April, 2026 T-index: 55 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 16.4 13.2 7.6 ASSXMM MMBFFF%%%. .. 10.5 8.5 4.5 00 01 17.9 14.9 8.4 ASSSXM MMMBFFF%%% %.... 11.2 9.8 5.0 01 02 19.1 16.1 8.9 SSSXX MMMMBBFFF% %%.... 11.6 10.6 5.3 02 03 19.2 16.7 9.2 SSSSX MMMMBBFFF% %%%.... 11.7 11.0 5.4 03 04 19.3 16.9 9.3 ASSSX XMMMBBFFF% %%%.... 11.7 11.2 5.5 04 05 19.0 16.7 9.3 SSSSX XMMMBBFF%% %%.... 11.8 11.1 5.4 05 06 18.5 16.1 9.0 SSSXX MMMMBBFF%% %%.... 11.5 10.7 5.2 06 07 18.5 15.1 8.5 ASSSXX MMMMBFFF%% %%..... 11.6 10.1 4.9 07 08 17.7 13.4 7.7 ASSXMM MMMMFFF%%% %..... 11.2 9.0 4.5 08 09 17.0 10.4 6.2 ASSMMMM MMMFFF%%%% ..... 10.7 6.9 3.6 09 10 13.2 2.2 0.0 XMMMMMMMMM MFF%%%%... ... 8.9 1.4 0.0 10 11 9.4 2.2 0.0 XMMMMMMMM% %%%...... 6.8 1.4 0.0 11 12 8.3 2.2 0.0 XMMMMMMM%% %%..... 5.8 1.4 0.0 12 13 7.2 2.2 0.0 XMMMMMM%%% ..... 5.1 1.4 0.0 13 14 7.3 2.2 0.0 XMMMMMF%%% .... 5.3 1.4 0.0 14 15 7.4 2.2 0.0 XMMMMMF%%% ... 5.3 1.4 0.0 15 16 7.5 2.2 0.0 XMMMMMF%%% ... 5.3 1.4 0.0 16 17 7.2 2.2 0.0 XMMMMMF%%. ... 5.2 1.4 0.0 17 18 7.0 2.2 0.0 XMMMMM%%%. ... 5.1 1.4 0.0 18 19 6.7 2.2 0.0 XMMMMM%%%. ... 4.6 1.4 0.0 19 20 6.1 2.2 0.0 XMMMMF%%.. .. 4.3 1.4 0.0 20 21 5.4 2.2 0.0 XMMMM%%... 3.8 1.4 0.0 21 22 6.8 2.2 0.0 XMMMMM%%.. . 4.9 1.4 0.0 22 23 13.2 9.9 6.0 ASMMMMF FFF%%... 8.2 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) 19-Apr-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000