SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 14 September, 2026 T-index: 65 Bearings: 184 5 Distance: 1251 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 18-23 1E 5 1 5 10 15 20 25 30 35 40 2F 37-43 2E 14 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 12.8 11.8 6.2 ASSXMMM BF%%%... 8.4 7.3 3.7 00 01 13.7 13.4 6.8 SSXXMM BBB%%%... 8.9 8.3 4.2 01 02 13.7 14.4 7.3 SSSXMM MBBP%%... 9.0 8.9 4.4 02 03 13.6 15.0 7.5 ASSXXM MBBPP%... 9.1 9.3 4.6 03 04 13.6 15.2 7.6 ASSXXM MBBPP%... 9.3 9.5 4.6 04 05 13.5 15.2 7.6 ASSXXM MBBPP%... 9.3 9.4 4.6 05 06 12.7 14.7 7.4 ASSXXM MBPP%%.. 8.8 9.1 4.5 06 07 12.2 13.9 7.1 SSSXMM BBP%%... 8.5 8.7 4.3 07 08 12.1 12.7 6.5 ASSXMMM BB%%%... 8.3 7.9 4.0 08 09 11.8 10.6 5.6 SSXMMMM F%%%%.. 8.1 6.6 3.4 09 10 10.8 5.5 3.3 ASMMMMMMF %%%%... 7.4 3.4 2.0 10 11 8.8 1.9 0.0 XMMMMMMM%% %%... 6.1 1.2 0.0 11 12 7.7 1.9 0.0 XMMMMMM%%% ... 5.5 1.2 0.0 12 13 7.0 1.9 0.0 XMMMMMM%%. .. 5.1 1.2 0.0 13 14 6.8 1.9 0.0 XMMMMM%%%. . 5.0 1.2 0.0 14 15 6.8 1.9 0.0 XMMMMM%%.. . 4.9 1.2 0.0 15 16 6.5 1.9 0.0 XMMMMM%%.. 4.7 1.2 0.0 16 17 6.2 1.9 0.0 XMMMMF%%.. 4.6 1.2 0.0 17 18 5.8 1.9 0.0 XMMMM%%.. 4.4 1.2 0.0 18 19 5.5 1.9 0.0 XMMMM%%.. 4.0 1.2 0.0 19 20 5.0 1.9 0.0 XMMMM%.. 3.7 1.2 0.0 20 21 4.8 1.9 0.0 XMMM%%.. 3.6 1.2 0.0 21 22 6.2 1.9 0.0 XMMMMF%.. 4.6 1.2 0.0 22 23 10.0 9.0 4.9 ASXMMMB% %%.. 6.9 5.5 3.0 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) 14-Sep-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000