SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 10 June, 2026 T-index: 75 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 12.7 10.0 5.3 SSMMMMB FF%%%.. 8.4 6.0 3.3 00 01 14.6 12.2 6.3 ASSXMMM MBFF%%%... 9.8 7.4 3.9 01 02 15.4 13.4 6.8 SSXXMM MMBFF%%%.. . 10.3 8.2 4.2 02 03 15.2 14.1 7.1 SSSXMM MMBBF%%%.. . 10.2 8.7 4.3 03 04 14.9 14.4 7.2 SSSXMM MBBB%%%... . 9.9 8.9 4.4 04 05 14.6 14.3 7.2 SSSXMM MBBB%%%... 9.7 8.8 4.4 05 06 14.7 13.8 7.0 SSXXMM MBBF%%%... 9.7 8.5 4.3 06 07 15.0 12.8 6.6 ASSXMMM MBFF%%%... . 9.7 7.9 4.0 07 08 14.7 11.2 5.9 ASXMMMM MFFF%%%... 9.6 6.8 3.6 08 09 13.5 7.9 4.4 ASMMMMMM FFF%%.... 8.9 4.6 2.8 09 10 10.6 2.0 0.0 XMMMMMMMFF %%%... 7.2 1.2 0.0 10 11 7.8 2.0 0.0 XMMMMMF%%% ... 5.4 1.2 0.0 11 12 6.3 2.0 0.0 XMMMMF%%.. . 4.6 1.2 0.0 12 13 5.8 2.0 0.0 XMMMM%%... 4.3 1.2 0.0 13 14 5.6 2.0 0.0 XMMMM%%... 4.2 1.2 0.0 14 15 5.3 2.0 0.0 XMMMM%... 4.1 1.2 0.0 15 16 5.3 2.0 0.0 XMMMM%%.. 4.0 1.2 0.0 16 17 5.4 2.0 0.0 XMMMM%%.. 4.0 1.2 0.0 17 18 5.4 2.0 0.0 XMMMM%%.. 3.9 1.2 0.0 18 19 5.3 2.0 0.0 XMMMM%%.. 3.8 1.2 0.0 19 20 5.3 2.0 0.0 XMMMM%%.. 3.6 1.2 0.0 20 21 4.9 2.0 0.0 XMMM%%... 3.4 1.2 0.0 21 22 5.2 2.0 0.0 XMMMF%.. 3.9 1.2 0.0 22 23 8.8 2.0 0.0 MMMMMMFF%% .. 5.9 0.0 1.7 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-Jun-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000