SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 7 June, 2026 T-index: 90 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 13.6 10.2 5.5 SSXMMMM FFF%%... 9.0 6.1 3.4 00 01 15.8 12.4 6.5 ASSXMMM MMFFF%%%.. . 10.5 7.6 4.0 01 02 16.7 13.6 7.0 SSXXMM MMBFFF%%%. .. 11.0 8.4 4.3 02 03 16.7 14.3 7.3 ASSXMM MMBBFF%%%. .. 11.1 8.8 4.5 03 04 16.2 14.6 7.4 ASSXMM MMBBFF%%.. . 10.8 9.0 4.5 04 05 15.7 14.5 7.4 ASSXMM MMBBF%%%.. . 10.5 9.0 4.5 05 06 15.7 14.0 7.2 SSSXMM MMBBF%%%.. . 10.4 8.7 4.4 06 07 16.1 13.1 6.8 SSXMMM MMBFFF%%.. .. 10.6 8.0 4.1 07 08 15.8 11.4 6.0 ASXMMMM MMFFF%%%.. . 10.4 7.0 3.7 08 09 14.7 8.1 4.5 ASMMMMMM MFFF%%%... 9.7 4.7 2.9 09 10 11.9 2.1 0.0 XMMMMMMMMF F%%%... 8.0 1.3 0.0 10 11 8.8 2.1 0.0 XMMMMMMF%% %... 6.1 1.3 0.0 11 12 7.1 2.1 0.0 XMMMMMF%%. . 5.0 1.3 0.0 12 13 6.4 2.1 0.0 XMMMMF%%.. 4.6 1.3 0.0 13 14 6.0 2.1 0.0 XMMMM%%... 4.4 1.3 0.0 14 15 5.7 2.1 0.0 XMMMM%%.. 4.3 1.3 0.0 15 16 5.6 2.1 0.0 XMMMM%%.. 4.2 1.3 0.0 16 17 5.6 2.1 0.0 XMMMM%%.. 4.2 1.3 0.0 17 18 5.5 2.1 0.0 XMMMM%%.. 4.0 1.3 0.0 18 19 5.3 2.1 0.0 XMMMM%%.. 3.8 1.3 0.0 19 20 5.3 2.1 0.0 XMMMM%%.. 3.7 1.3 0.0 20 21 4.9 2.1 0.0 XMMM%%... 3.5 1.3 0.0 21 22 5.3 2.1 0.0 XMMMF%.. 4.0 1.3 0.0 22 23 9.4 2.1 0.0 MMMMMMMFF% %. 6.2 0.0 1.8 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) 7-Jun-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000