SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 24 May, 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 18-21 1E 5 1 5 10 15 20 25 30 35 40 2F 36-40 2E 14 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 12.5 10.1 5.3 SSXMMMB FF%%... 8.4 6.1 3.3 00 01 14.3 12.1 6.2 ASSXMMM MBFF%%... 9.6 7.4 3.8 01 02 14.7 13.3 6.7 SSXXMM MBBF%%%... 9.9 8.2 4.1 02 03 14.8 14.0 7.0 SSXXMM MBBB%%%... . 9.7 8.6 4.3 03 04 14.5 14.3 7.1 SSSXMM MBBB%%%... 9.6 8.8 4.3 04 05 14.2 14.2 7.1 SSSXMM MBBB%%.... 9.4 8.8 4.3 05 06 14.3 13.7 6.9 SSXXMM MBBF%%%... 9.4 8.5 4.2 06 07 14.8 12.8 6.5 ASSXMMM MBFF%%%... 9.5 7.9 4.0 07 08 14.5 11.2 5.8 ASXMMMM MFFF%%%... 9.4 6.9 3.6 08 09 13.3 8.3 4.5 ASMMMMMM FFF%%... 8.7 4.9 2.8 09 10 10.3 1.9 0.0 XMMMMMMMFF %%.... 7.0 1.2 0.0 10 11 7.8 1.9 0.0 XMMMMMF%%% ... 5.4 1.2 0.0 11 12 6.4 1.9 0.0 XMMMMF%%.. . 4.6 1.2 0.0 12 13 5.9 1.9 0.0 XMMMM%%... 4.3 1.2 0.0 13 14 5.7 1.9 0.0 XMMMM%%... 4.2 1.2 0.0 14 15 5.5 1.9 0.0 XMMMM%%.. 4.1 1.2 0.0 15 16 5.6 1.9 0.0 XMMMM%%.. 4.1 1.2 0.0 16 17 5.5 1.9 0.0 XMMMM%%.. 4.0 1.2 0.0 17 18 5.4 1.9 0.0 XMMMM%%.. 3.9 1.2 0.0 18 19 5.2 1.9 0.0 XMMMM%%.. 3.7 1.2 0.0 19 20 5.2 1.9 0.0 XMMMM%%.. 3.5 1.2 0.0 20 21 4.8 1.9 0.0 XMMM%%... 3.4 1.2 0.0 21 22 5.1 1.9 0.0 XMMMF%.. 3.9 1.2 0.0 22 23 9.1 3.9 2.4 AMMMMMFF% .. 6.1 0.0 2.0 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-May-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000