SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 19 November, 2025 T-index: 115 Bearings: 184 5 Distance: 1251 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 19-30 1E 5 1 5 10 15 20 25 30 35 40 2F 38-51 2E 14 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 11.1 13.7 7.3 SSSXMB BPP.... 7.9 8.6 4.4 00 01 11.3 15.0 7.9 ASSXXM BPPPE.. 8.3 9.4 4.8 01 02 11.8 15.9 8.3 ASSSXM BPPPE... 8.8 9.9 5.0 02 03 12.3 16.4 8.5 SSSXX MBPPPE.. 9.2 10.2 5.1 03 04 12.8 16.6 8.6 SSSXX MBPPPE... 9.4 10.4 5.2 04 05 13.1 16.6 8.6 SSSXX MBBPPP... 9.6 10.3 5.2 05 06 13.0 16.2 8.4 SSSXX MBPPPP... 9.4 10.1 5.1 06 07 12.4 15.5 8.1 ASSSXM MBPPP... 9.0 9.7 4.9 07 08 11.9 14.4 7.6 ASSXMM MPPP%.. 8.8 9.0 4.6 08 09 12.0 12.8 6.9 SSXMMM MP%%%... 8.7 8.0 4.2 09 10 12.0 10.3 5.7 ASXMMMM M%%%%.. 8.8 6.3 3.5 10 11 11.8 2.2 0.0 XMMMMMMMMM F%%%... 8.6 1.4 0.9 11 12 10.9 2.2 0.0 XMMMMMMMMM %%%.. 8.1 1.4 0.0 12 13 10.1 2.2 0.0 XMMMMMMMMF %%.. 7.6 1.4 0.0 13 14 9.6 2.2 0.0 XMMMMMMMF% %%.. 7.2 1.4 0.0 14 15 9.5 2.2 0.0 XMMMMMMMF% %%.. 7.0 1.4 0.0 15 16 9.7 2.2 0.0 XMMMMMMMF% %%.. 7.0 1.4 0.0 16 17 9.0 2.2 0.0 XMMMMMMM%% %.. 6.6 1.4 0.0 17 18 8.0 2.2 0.0 XMMMMMM%%% .. 6.0 1.4 0.0 18 19 7.4 2.2 0.0 XMMMMMM%%. . 5.6 1.4 0.0 19 20 7.1 2.2 0.0 XMMMMMF%%. . 5.3 1.4 0.0 20 21 7.2 2.2 0.0 XMMMMMM%%. . 5.5 1.4 0.0 21 22 9.1 8.2 4.7 ASMMMMF% %... 6.6 4.9 2.9 22 23 10.6 11.8 6.4 ASSXMMB P%%... 7.5 7.4 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) 19-Nov-2025 BoM Space Weather Services, Sydney Australia +61-2-9213-8000