SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 10 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 12.9 10.5 5.5 SSXMMMM FF%%%... 8.8 6.3 3.4 00 01 14.7 12.4 6.3 ASSXMMM MBFF%%%... 9.8 7.6 3.9 01 02 15.2 13.5 6.8 SSXXMM MMBFF%%%.. . 10.1 8.3 4.2 02 03 15.3 14.2 7.1 SSSXMM MMBBF%%%.. . 10.1 8.8 4.3 03 04 15.1 14.5 7.2 SSSXMM MMBBF%%%.. . 10.0 8.9 4.4 04 05 14.8 14.4 7.2 SSSXMM MBBB%%%... 9.8 8.9 4.4 05 06 14.8 13.9 7.0 SSXXMM MMBF%%%... . 9.8 8.6 4.3 06 07 15.1 13.0 6.6 ASSXMMM MMBFF%%%.. . 9.9 8.0 4.0 07 08 14.9 11.5 6.0 ASXXMMM MMFF%%%... . 9.7 7.1 3.6 08 09 13.9 8.8 4.8 ASXMMMMM MFF%%%... 9.2 5.3 2.9 09 10 10.8 1.9 0.0 XMMMMMMMMF %%%.... 7.4 1.2 0.0 10 11 8.4 1.9 0.0 XMMMMMMF%% %... 5.7 1.2 0.0 11 12 6.9 1.9 0.0 XMMMMM%%%. .. 4.9 1.2 0.0 12 13 6.2 1.9 0.0 XMMMMF%%.. . 4.5 1.2 0.0 13 14 5.9 1.9 0.0 XMMMM%%... 4.4 1.2 0.0 14 15 5.8 1.9 0.0 XMMMM%%.. 4.4 1.2 0.0 15 16 5.8 1.9 0.0 XMMMM%%... 4.4 1.2 0.0 16 17 5.7 1.9 0.0 XMMMM%%.. 4.2 1.2 0.0 17 18 5.6 1.9 0.0 XMMMM%%.. 4.1 1.2 0.0 18 19 5.5 1.9 0.0 XMMMM%%.. 3.8 1.2 0.0 19 20 5.3 1.9 0.0 XMMMM%%.. 3.7 1.2 0.0 20 21 4.9 1.9 0.0 XMMM%%.. 3.5 1.2 0.0 21 22 5.2 1.9 0.0 XMMMM%.. 4.0 1.2 0.0 22 23 9.6 5.8 3.3 SMMMMFF% %.. 6.4 2.7 2.3 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) 10-May-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000