SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 30 July, 2026 T-index: 90 Bearings: 201 24 Distance: 1680 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 12-16 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 16.6 12.9 7.6 ASSXMM MMFFFF%%%. .. 10.4 8.2 4.6 00 01 18.7 15.0 8.6 SSSXM MMMBBFFF%% %.... 11.6 9.7 5.1 01 02 18.8 16.2 9.2 ASSSX MMMBBBFF%% %%.... 12.0 10.6 5.5 02 03 18.8 16.9 9.6 ASSSX XMMBBBFF%% %%.... 12.1 11.1 5.6 03 04 17.7 17.1 9.7 ASSSX XMMBBBB%%% ..... 11.5 11.3 5.7 04 05 17.4 16.9 9.6 ASSSX XMMBBBF%%% .... 11.3 11.2 5.6 05 06 16.6 16.3 9.3 SSSSX MMBBBB%%%. .... 10.9 10.8 5.4 06 07 16.4 15.1 8.7 SSSXX MMBBBF%%%. .... 10.7 10.1 5.1 07 08 16.3 13.2 7.8 ASSXMM MMBFFF%%%. .... 10.6 8.8 4.5 08 09 16.3 9.4 5.9 SSXMMMM MMFFFF%%%. .... 10.7 6.3 3.4 09 10 13.2 2.4 0.0 XMMMMMMMMM FFF%%%.... . 8.9 1.6 0.0 10 11 10.2 2.4 0.0 XMMMMMMMFF %%%..... 7.1 1.6 0.0 11 12 8.7 2.4 0.0 XMMMMMMF%% %.... 6.1 1.6 0.0 12 13 7.9 2.4 0.0 XMMMMMF%%% .... 5.5 1.6 0.0 13 14 7.2 2.4 0.0 XMMMMMF%%. ... 5.2 1.6 0.0 14 15 6.7 2.4 0.0 XMMMMM%%%. .. 5.0 1.6 0.0 15 16 6.6 2.4 0.0 XMMMMM%%%. .. 4.9 1.6 0.0 16 17 6.4 2.4 0.0 XMMMMM%%.. .. 4.9 1.6 0.0 17 18 6.1 2.4 0.0 XMMMMM%%.. .. 4.6 1.6 0.0 18 19 5.8 2.4 0.0 XMMMM%%%.. .. 4.2 1.6 0.0 19 20 5.2 2.4 0.0 XMMMM%%... . 3.8 1.6 0.0 20 21 5.0 2.4 0.0 XMMMM%%... 3.7 1.6 0.0 21 22 6.1 2.4 0.0 XMMMMF%%.. 4.5 1.6 0.0 22 23 12.5 8.7 5.5 ASMMMFF FF%%... 7.6 4.4 3.6 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-Jul-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000