SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 2 February, 2026 T-index: 120 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 10.9 13.7 7.3 SSSXMB PPP.... 7.7 8.5 4.4 00 01 11.5 15.0 7.9 ASSXXM BPPPE... 8.1 9.4 4.8 01 02 11.9 15.9 8.3 ASSSXM BPPPE... 8.6 9.9 5.0 02 03 12.5 16.5 8.6 SSSXX MBPPPE.. 9.0 10.2 5.2 03 04 12.8 16.7 8.7 SSSXX MBPPPE... 9.2 10.4 5.2 04 05 13.1 16.6 8.6 SSSXX MBBPPP... 9.4 10.3 5.2 05 06 13.3 16.2 8.5 SSSXX MBBPPP.... 9.4 10.1 5.1 06 07 12.9 15.5 8.1 ASSSXM MBPPP%... 9.1 9.7 4.9 07 08 12.4 14.4 7.7 ASSXMM MBPP%... 8.8 9.0 4.6 08 09 11.9 12.8 6.9 SSXMMM BP%%%... 8.5 8.0 4.2 09 10 11.8 10.1 5.7 ASXMMMM F%%%... 8.4 6.2 3.5 10 11 11.7 2.3 0.0 XMMMMMMMMM F%%%.. 8.3 1.4 0.0 11 12 11.1 2.3 0.0 XMMMMMMMMF F%%.. 8.0 1.4 0.0 12 13 10.6 2.3 0.0 XMMMMMMMMF %%%.. 7.8 1.4 0.0 13 14 9.7 2.3 0.0 XMMMMMMMF% %%.. 7.1 1.4 0.0 14 15 9.5 2.3 0.0 XMMMMMMMF% %.. 6.9 1.4 0.0 15 16 9.5 2.3 0.0 XMMMMMMMF% %.. 6.8 1.4 0.0 16 17 9.2 2.3 0.0 XMMMMMMMF% %.. 6.6 1.4 0.0 17 18 8.2 2.3 0.0 XMMMMMMF%% .. 6.0 1.4 0.0 18 19 7.5 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 7.7 7.7 4.5 ASMMM%%. .. 5.7 4.6 2.8 22 23 9.8 11.7 6.4 ASSXMBP P%... 6.9 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) 2-Feb-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000