SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 6 February, 2026 T-index: 130 Bearings: 184 5 Distance: 1251 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 19-29 1E 5 1 5 10 15 20 25 30 35 40 2F 37-49 2E 14 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 11.6 13.8 7.4 ASSXMB BPP%... 8.1 8.6 4.5 00 01 12.3 15.1 8.0 ASSXXM BBPPE... 8.6 9.4 4.9 01 02 12.5 16.1 8.5 SSSXM MBPPPE.. 9.0 10.0 5.1 02 03 12.9 16.6 8.7 SSSXX MBPPPP... 9.2 10.3 5.3 03 04 13.2 16.8 8.8 SSSXX MBBPPP... 9.5 10.5 5.3 04 05 13.4 16.8 8.8 SSSXX MBBPPP.... 9.6 10.4 5.3 05 06 13.6 16.4 8.6 SSSXX MMBPPP%... 9.7 10.2 5.2 06 07 13.3 15.6 8.3 ASSSXM MBBPP%.... 9.4 9.7 5.0 07 08 12.7 14.5 7.8 ASSXXM MBPP%%... 9.1 9.1 4.7 08 09 12.3 12.8 7.0 SSXMMM MB%%%... 8.8 8.0 4.2 09 10 12.3 10.0 5.7 ASXMMMM FF%%%.. 8.8 6.1 3.5 10 11 12.3 2.3 0.0 XMMMMMMMMM FF%%... 8.8 1.4 0.0 11 12 11.6 2.3 0.0 XMMMMMMMMM F%%... 8.4 1.4 0.0 12 13 11.2 2.3 0.0 XMMMMMMMMF F%%.. 8.2 1.4 0.0 13 14 10.1 2.3 0.0 XMMMMMMMMF %%.. 7.4 1.4 0.0 14 15 9.7 2.3 0.0 XMMMMMMMF% %%.. 7.1 1.4 0.0 15 16 9.6 2.3 0.0 XMMMMMMMF% %... 6.9 1.4 0.0 16 17 9.3 2.3 0.0 XMMMMMMMF% %.. 6.8 1.4 0.0 17 18 8.3 2.3 0.0 XMMMMMMF%% .. 6.1 1.4 0.0 18 19 7.4 2.3 0.0 XMMMMMM%%% . 5.4 1.4 0.0 19 20 6.7 2.3 0.0 XMMMMM%%%. 5.0 1.4 0.0 20 21 6.3 2.3 0.0 XMMMMM%%. 4.8 1.4 0.0 21 22 7.9 7.5 4.4 ASMMM%%% .. 5.8 4.5 2.8 22 23 10.4 11.7 6.5 ASSXMBB P%.... 7.3 7.3 3.9 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) 6-Feb-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000