SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 21 March, 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 12-16 1E 2 1 5 10 15 20 25 30 35 40 2F 28-34 2E 10 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 14.8 14.0 8.0 ASSXXM MBBB%%%... 9.5 9.2 4.7 00 01 16.2 15.6 8.8 SSSXX MMBBBF%%%. .. 10.2 10.3 5.2 01 02 16.9 16.6 9.3 SSSSX MMBBBB%%%% ... 10.2 11.0 5.4 02 03 17.4 17.2 9.5 ASSSX XMBBBBB%%% .... 10.3 11.4 5.6 03 04 17.7 17.4 9.6 ASSSX XMMBBBB%%% .... 10.6 11.6 5.6 04 05 17.8 17.2 9.5 ASSSX XMMBBBB%%% %... 10.8 11.5 5.6 05 06 17.4 16.7 9.3 SSSSX XMMBBBF%%% %... 10.7 11.1 5.4 06 07 17.2 15.7 8.8 SSSXX MMMBBFF%%% %.... 10.4 10.5 5.1 07 08 17.0 14.2 8.1 ASSSXM MMBBFF%%%% .... 10.2 9.5 4.7 08 09 16.5 11.7 6.9 SSXMMM MMFFFF%%%% .... 10.1 7.7 4.1 09 10 13.5 4.7 3.2 AMMMMMMM MFF%%%%%.. ... 8.8 0.0 2.5 10 11 10.3 2.2 0.0 XMMMMMMMMM %%%%%..... . 7.2 1.4 0.0 11 12 8.6 2.2 0.0 XMMMMMMM%% %%...... 6.3 1.4 0.0 12 13 7.9 2.2 0.0 XMMMMMM%%% %..... 5.7 1.4 0.0 13 14 7.7 2.2 0.0 XMMMMMM%%% %.... 5.5 1.4 0.0 14 15 8.1 2.2 0.0 XMMMMMMF%% .... 5.6 1.4 0.0 15 16 8.0 2.2 0.0 XMMMMMM%%% .... 5.5 1.4 0.0 16 17 8.0 2.2 0.0 XMMMMMM%%% .... 5.4 1.4 0.0 17 18 7.5 2.2 0.0 XMMMMMF%%% .... 5.3 1.4 0.0 18 19 7.0 2.2 0.0 XMMMMM%%%. ... 5.1 1.4 0.0 19 20 6.0 2.2 0.0 XMMMMM%%.. . 4.4 1.4 0.0 20 21 5.5 2.2 0.0 XMMMM%%... 4.1 1.4 0.0 21 22 7.9 2.2 0.0 MMMMMMF%%% .. 5.4 0.0 1.9 22 23 12.9 11.4 6.8 ASSXMMB BF%%%.. 8.0 7.3 4.0 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-Mar-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000