SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 24 March, 2026 T-index: 55 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 11.9 11.8 6.1 ASSXMMB B%%%... 8.1 7.3 3.7 00 01 12.9 13.4 6.8 SSXXMM BBP%%... 8.7 8.3 4.1 01 02 13.4 14.3 7.2 SSSXMM MBBP%%... 8.9 8.9 4.4 02 03 13.5 14.9 7.4 ASSXXM MBBP%%... 9.0 9.2 4.5 03 04 13.7 15.1 7.5 ASSXXM MBBPP%%.. 9.3 9.4 4.6 04 05 13.8 15.1 7.5 ASSXXM MBBPP%%... 9.5 9.3 4.5 05 06 13.6 14.6 7.3 SSSXXM MBBP%%%.. 9.4 9.1 4.4 06 07 13.4 13.9 7.0 SSXXMM MBB%%%%.. 9.1 8.6 4.2 07 08 13.3 12.6 6.5 ASSXMMM MBF%%%%.. 8.9 7.9 3.9 08 09 13.1 10.7 5.6 SSXMMMM MFF%%%... 8.7 6.6 3.4 09 10 11.4 6.2 3.6 SMMMMMMM F%%%%... 7.6 3.9 2.2 10 11 9.1 1.9 0.0 XMMMMMMMF% %%.... 6.3 1.2 0.0 11 12 7.6 1.9 0.0 XMMMMMM%%% ... 5.5 1.2 0.0 12 13 6.8 1.9 0.0 XMMMMM%%%. .. 5.0 1.2 0.0 13 14 6.5 1.9 0.0 XMMMMM%%.. . 4.8 1.2 0.0 14 15 6.5 1.9 0.0 XMMMMM%%.. 4.9 1.2 0.0 15 16 6.4 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 6.2 1.9 0.0 XMMMMM%%.. 4.6 1.2 0.0 18 19 6.1 1.9 0.0 XMMMMF%... 4.5 1.2 0.0 19 20 5.4 1.9 0.0 XMMMM%%.. 4.0 1.2 0.0 20 21 4.8 1.9 0.0 XMMM%%.. 3.6 1.2 0.0 21 22 6.0 1.9 0.0 XMMMM%%.. 4.5 1.2 0.0 22 23 9.6 9.2 4.9 ASXMMMB% %... 6.6 5.6 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) 24-Mar-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000