SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 28 September, 2026 T-index: 60 Bearings: 184 5 Distance: 1251 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 18-24 1E 5 1 5 10 15 20 25 30 35 40 2F 37-44 2E 14 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 12.2 12.1 6.3 ASSXMMB BB%%%.. 8.0 7.5 3.8 00 01 12.8 13.6 6.9 SSXXMM BBP%%... 8.3 8.4 4.2 01 02 12.9 14.5 7.3 SSSXMM BBPP%... 8.5 9.0 4.4 02 03 12.9 15.1 7.6 ASSXXM BBPPP... 8.8 9.4 4.6 03 04 13.2 15.3 7.7 ASSXXM MBBPP%... 9.1 9.5 4.6 04 05 13.3 15.3 7.6 ASSXXM MBBPP%... 9.2 9.5 4.6 05 06 12.5 14.9 7.5 ASSXXM BBPP%... 8.7 9.2 4.5 06 07 11.9 14.1 7.1 SSSXMM BPPP%.. 8.3 8.8 4.3 07 08 11.7 12.9 6.6 ASSXMMM BP%%... 8.1 8.0 4.0 08 09 11.6 11.0 5.8 ASXMMMM B%%%... 7.9 6.9 3.5 09 10 10.7 7.2 4.0 AXMMMMMF %%%%... 7.4 4.4 2.5 10 11 9.1 1.9 0.0 XMMMMMMMF% %%.... 6.3 1.2 0.0 11 12 8.0 1.9 0.0 XMMMMMM%%% %... 5.7 1.2 0.0 12 13 7.3 1.9 0.0 XMMMMMM%%% ... 5.2 1.2 0.0 13 14 7.0 1.9 0.0 XMMMMM%%%. .. 5.1 1.2 0.0 14 15 7.0 1.9 0.0 XMMMMM%%%. . 5.0 1.2 0.0 15 16 6.7 1.9 0.0 XMMMMM%%.. . 4.8 1.2 0.0 16 17 6.4 1.9 0.0 XMMMMM%%.. 4.7 1.2 0.0 17 18 6.0 1.9 0.0 XMMMM%%.. 4.5 1.2 0.0 18 19 5.5 1.9 0.0 XMMMM%%.. 4.2 1.2 0.0 19 20 5.1 1.9 0.0 XMMMM%.. 3.9 1.2 0.0 20 21 5.1 1.9 0.0 XMMMM%.. 3.9 1.2 0.0 21 22 6.9 1.9 0.0 XMMMMM%%.. 5.0 1.2 0.0 22 23 10.3 9.6 5.2 SSMMMBF %%... 7.0 5.9 3.1 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) 28-Sep-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000