SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Broome Perth Date: 4 April, 2026 T-index: 50 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 15.4 13.5 7.8 ASSXMM MMBFF%%%.. . 9.9 8.8 4.6 00 01 16.8 15.2 8.5 ASSSXM MMBBBF%%%% ... 10.6 10.0 5.0 01 02 17.9 16.3 9.0 SSSXX MMMBBBF%%% %... 10.8 10.7 5.3 02 03 18.1 16.9 9.3 SSSSX XMMBBBFF%% %.... 10.9 11.2 5.4 03 04 18.4 17.1 9.4 ASSSX XMMBBBBF%% %%... 11.0 11.3 5.5 04 05 18.2 16.9 9.3 SSSSX XMMBBBFF%% %.... 11.2 11.2 5.4 05 06 17.8 16.3 9.1 SSSSX MMMBBBF%%% %.... 11.0 10.9 5.3 06 07 17.8 15.3 8.6 ASSSXX MMMBBFF%%% %..... 10.9 10.3 5.0 07 08 17.2 13.8 7.9 ASSXXM MMMFFFF%%% %.... 10.6 9.2 4.6 08 09 16.6 11.1 6.5 ASSXMMM MMFFFF%%%% .... 10.4 7.3 3.8 09 10 13.1 2.1 0.0 XMMMMMMMMM MFF%%%%... ... 8.7 1.4 0.0 10 11 9.5 2.1 0.0 XMMMMMMMM% %%%%..... 6.8 1.4 0.0 11 12 8.2 2.1 0.0 XMMMMMMM%% %%..... 5.9 1.4 0.0 12 13 7.3 2.1 0.0 XMMMMMM%%% ..... 5.3 1.4 0.0 13 14 7.2 2.1 0.0 XMMMMMM%%% .... 5.3 1.4 0.0 14 15 7.6 2.1 0.0 XMMMMMF%%% ... 5.4 1.4 0.0 15 16 7.6 2.1 0.0 XMMMMMF%%% ... 5.3 1.4 0.0 16 17 7.5 2.1 0.0 XMMMMMF%%% ... 5.3 1.4 0.0 17 18 7.2 2.1 0.0 XMMMMMF%%. ... 5.3 1.4 0.0 18 19 6.8 2.1 0.0 XMMMMM%%%. .. 4.8 1.4 0.0 19 20 6.0 2.1 0.0 XMMMM%%%.. . 4.3 1.4 0.0 20 21 5.3 2.1 0.0 XMMMM%%... 3.9 1.4 0.0 21 22 7.3 2.1 0.0 XMMMMMF%%. .. 5.1 1.4 0.0 22 23 12.9 10.7 6.4 ASSMMMB FF%%%... 8.1 6.7 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) 4-Apr-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000