SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 21 August, 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 16.2 13.4 7.8 ASSXMM MBBFFF%%%. .. 10.1 8.6 4.7 00 01 17.8 15.2 8.7 SSSXM MMMBBFF%%% %... 11.0 10.0 5.1 01 02 17.9 16.4 9.2 SSSSX MMMBBBF%%% %.... 11.2 10.8 5.4 02 03 17.9 17.0 9.5 ASSSX XMMBBBB%%% %..... 11.3 11.2 5.6 03 04 17.2 17.2 9.6 ASSSX XMMBBBB%%% ..... 11.2 11.4 5.7 04 05 16.9 17.1 9.6 ASSSX XMMBBBP%%% .... 10.9 11.3 5.6 05 06 16.2 16.5 9.3 SSSSX MMBBBB%%%. .... 10.5 11.0 5.4 06 07 15.7 15.4 8.8 SSSXX MMBBB%%%%. .... 10.3 10.3 5.1 07 08 15.4 13.6 7.9 ASSXXM MMBFF%%%.. ... 10.1 9.1 4.6 08 09 15.4 10.5 6.4 ASSMMMM MMFFF%%%.. ... 10.2 7.0 3.7 09 10 12.9 2.3 0.0 XMMMMMMMMM MF%%%%.... .. 8.7 1.5 0.0 10 11 10.1 2.3 0.0 XMMMMMMMMF %%%...... 7.0 1.5 0.0 11 12 8.8 2.3 0.0 XMMMMMMF%% %%..... 6.1 1.5 0.0 12 13 8.0 2.3 0.0 XMMMMMM%%% ..... 5.6 1.5 0.0 13 14 7.6 2.3 0.0 XMMMMMM%%% .... 5.4 1.5 0.0 14 15 7.3 2.3 0.0 XMMMMMF%%% .... 5.2 1.5 0.0 15 16 7.0 2.3 0.0 XMMMMM%%%. ... 5.1 1.5 0.0 16 17 6.8 2.3 0.0 XMMMMM%%%. ... 5.0 1.5 0.0 17 18 6.4 2.3 0.0 XMMMMM%%%. .. 4.9 1.5 0.0 18 19 6.1 2.3 0.0 XMMMMM%%.. .. 4.5 1.5 0.0 19 20 5.4 2.3 0.0 XMMMM%%%.. . 3.9 1.5 0.0 20 21 5.0 2.3 0.0 XMMMM%%... 3.9 1.5 0.0 21 22 6.4 2.3 0.0 XMMMMF%%.. . 4.7 1.5 0.0 22 23 13.0 10.0 6.1 ASSMMMB FF%%%... 8.0 5.9 3.8 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) 21-Aug-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000