SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 25 July, 2026 T-index: 75 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 15.5 12.6 7.4 ASSMMM MBFFF%%%.. . 9.8 8.0 4.5 00 01 17.3 14.6 8.4 ASSSXM MMBBFFF%%% .... 10.9 9.5 5.0 01 02 17.4 15.8 8.9 SSSXX MMMBBFF%%% ..... 11.3 10.4 5.3 02 03 17.3 16.5 9.3 ASSSX MMMBBBF%%% %..... 11.3 10.9 5.5 03 04 16.3 16.8 9.4 ASSSX XMBBBB%%%. .... 10.8 11.1 5.5 04 05 16.1 16.6 9.3 SSSSX MMBBBB%%%. .... 10.6 11.0 5.4 05 06 15.4 15.9 9.0 SSSXX MMBBB%%%%. ... 10.1 10.6 5.3 06 07 15.3 14.8 8.4 ASSSXM MMBBF%%%.. .... 10.0 9.8 4.9 07 08 15.1 12.8 7.5 SSSXMM MMFFF%%%.. ... 10.0 8.5 4.4 08 09 14.9 9.0 5.6 SSMMMMM MMFF%%%%.. ... 9.9 6.0 3.2 09 10 11.8 2.3 0.0 XMMMMMMMMM F%%%%..... 8.1 1.5 0.0 10 11 9.0 2.3 0.0 XMMMMMMM%% %%..... 6.4 1.5 0.0 11 12 7.8 2.3 0.0 XMMMMMM%%% ..... 5.5 1.5 0.0 12 13 7.1 2.3 0.0 XMMMMMF%%. .... 5.1 1.5 0.0 13 14 6.6 2.3 0.0 XMMMMM%%%. .. 4.8 1.5 0.0 14 15 6.2 2.3 0.0 XMMMMM%%.. .. 4.7 1.5 0.0 15 16 6.2 2.3 0.0 XMMMMF%%.. .. 4.6 1.5 0.0 16 17 6.0 2.3 0.0 XMMMM%%%.. . 4.6 1.5 0.0 17 18 5.8 2.3 0.0 XMMMM%%%.. . 4.3 1.5 0.0 18 19 5.5 2.3 0.0 XMMMM%%%.. . 4.1 1.5 0.0 19 20 5.0 2.3 0.0 XMMMM%%... 3.6 1.5 0.0 20 21 4.9 2.3 0.0 XMMMM%%... 3.6 1.5 0.0 21 22 6.0 2.3 0.0 XMMMM%%... 4.4 1.5 0.0 22 23 11.5 8.2 5.2 SSMMMFF F%%... 7.1 3.8 3.4 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) 25-Jul-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000