SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 8 January, 2026 T-index: 105 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 10.2 13.7 7.2 SSXXBB PPE.. 7.0 8.6 4.4 00 01 11.1 14.9 7.8 ASSXXB BPEE.. 7.4 9.3 4.7 01 02 11.7 15.8 8.2 ASSXXM BPPEE.. 7.9 9.8 4.9 02 03 12.1 16.3 8.4 SSSXX BBPPEE. 8.3 10.1 5.1 03 04 12.3 16.5 8.5 SSSXX BBPPEE.. 8.6 10.3 5.1 04 05 12.2 16.4 8.4 SSSXX MBPPPE.. 8.8 10.2 5.1 05 06 12.3 16.1 8.3 ASSSXM MBPPPE.. 8.7 10.0 5.0 06 07 11.8 15.4 8.0 ASSXXM BPPPP... 8.3 9.6 4.8 07 08 11.3 14.4 7.5 ASSXMM BPPP... 8.1 9.0 4.6 08 09 11.0 12.8 6.9 SSXMMM PP%%... 7.9 8.0 4.2 09 10 10.7 10.5 5.8 ASXMMMB %%%... 7.6 6.4 3.6 10 11 10.5 3.2 2.2 MMMMMMMF %%%.. 7.6 0.0 2.1 11 12 10.1 2.2 0.0 XMMMMMMMMF %%... 7.4 1.3 0.0 12 13 9.8 2.2 0.0 XMMMMMMMM% %%.. 7.2 1.3 0.0 13 14 9.4 2.2 0.0 XMMMMMMMF% %%.. 6.9 1.3 0.0 14 15 9.4 2.2 0.0 XMMMMMMMF% %%.. 6.8 1.3 0.0 15 16 9.3 2.2 0.0 XMMMMMMMF% %... 6.6 1.3 0.0 16 17 8.9 2.2 0.0 XMMMMMMM%% %.. 6.3 1.3 0.0 17 18 8.1 2.2 0.0 XMMMMMMF%% .. 5.9 1.3 0.0 18 19 7.6 2.2 0.0 XMMMMMF%%. .. 5.5 1.3 0.0 19 20 6.7 2.2 0.0 XMMMMM%%.. 5.1 1.3 0.0 20 21 6.5 2.2 0.0 XMMMMM%%.. 5.0 1.3 0.0 21 22 7.9 8.6 4.9 SXMMP%% .. 5.8 5.2 3.1 22 23 9.2 11.9 6.4 ASSXMBP P.... 6.6 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) 8-Jan-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000