SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 20 August, 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 15.8 13.3 7.7 ASSXMM MBBFF%%%.. .. 10.0 8.5 4.6 00 01 17.5 15.1 8.6 SSSXM MMBBBFF%%% .... 10.9 9.9 5.1 01 02 17.6 16.3 9.2 SSSSX MMMBBBF%%% %.... 11.0 10.7 5.4 02 03 17.3 16.9 9.5 ASSSX XMMBBBF%%% %.... 11.0 11.2 5.5 03 04 16.7 17.1 9.6 ASSSX XMBBBBP%%% .... 10.9 11.3 5.6 04 05 16.3 16.9 9.5 ASSSX XMBBBB%%%. .... 10.6 11.2 5.5 05 06 15.7 16.4 9.2 SSSSX MMBBBP%%%. .... 10.3 10.9 5.4 06 07 15.2 15.3 8.7 SSSXX MMBBB%%%%. ... 10.0 10.2 5.1 07 08 14.9 13.5 7.8 ASSXMM MMBF%%%%.. ... 9.8 9.0 4.5 08 09 14.9 10.3 6.3 ASSMMMM MFFF%%%%.. ... 9.9 6.9 3.7 09 10 12.6 2.3 0.0 XMMMMMMMMM FF%%%%.... .. 8.5 1.5 0.0 10 11 9.8 2.3 0.0 XMMMMMMMF% %%%...... 6.9 1.5 0.0 11 12 8.5 2.3 0.0 XMMMMMMF%% %..... 6.0 1.5 0.0 12 13 7.7 2.3 0.0 XMMMMMM%%% ..... 5.5 1.5 0.0 13 14 7.5 2.3 0.0 XMMMMMF%%% .... 5.3 1.5 0.0 14 15 7.3 2.3 0.0 XMMMMMF%%% ... 5.1 1.5 0.0 15 16 7.0 2.3 0.0 XMMMMM%%%. ... 5.0 1.5 0.0 16 17 6.8 2.3 0.0 XMMMMM%%%. .. 4.9 1.5 0.0 17 18 6.4 2.3 0.0 XMMMMM%%%. .. 4.8 1.5 0.0 18 19 6.0 2.3 0.0 XMMMMM%%.. .. 4.4 1.5 0.0 19 20 5.3 2.3 0.0 XMMMM%%... . 3.9 1.5 0.0 20 21 4.9 2.3 0.0 XMMMM%%... 3.8 1.5 0.0 21 22 6.2 2.3 0.0 XMMMMF%%.. 4.6 1.5 0.0 22 23 12.7 9.8 6.0 ASMMMMF FF%%%... 8.0 5.8 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-Aug-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000