SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: PortHedlandPerth Date: 6 July, 2025 T-index: 90 Bearings: 191 12 Distance: 1323 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 17-20 1E 4 1 5 10 15 20 25 30 35 40 2F 35-39 2E 13 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 13.5 10.6 5.8 ASXMMMM FFF%%... 8.6 6.2 3.5 00 01 15.4 12.8 6.7 ASSXMMM MBFFF%%%.. . 9.9 7.6 4.0 01 02 16.2 14.0 7.3 SSSXMM MMBBFF%%.. . 10.4 8.4 4.3 02 03 16.3 14.7 7.6 ASSXMM MMBBFF%%.. . 10.5 8.9 4.5 03 04 15.5 15.0 7.7 ASSXMM MBBBB%%... 10.1 9.0 4.5 04 05 15.1 14.9 7.6 ASSXMM MBBBF%%... 9.8 9.0 4.5 05 06 14.7 14.3 7.4 SSSXMM MBBB%%%.. 9.6 8.6 4.4 06 07 14.7 13.3 7.0 SSXMMM MBBF%%%... 9.6 8.0 4.1 07 08 14.7 11.6 6.2 ASSMMMM MFFF%%%... 9.5 6.9 3.7 08 09 14.2 8.0 4.5 ASMMMMMM FFFF%%... 9.2 4.6 2.8 09 10 11.3 2.1 0.0 XMMMMMMMMF F%%... 7.5 1.3 0.0 10 11 8.4 2.1 0.0 XMMMMMMF%% ... 5.8 1.3 0.0 11 12 6.9 2.1 0.0 XMMMMM%%.. . 4.9 1.3 0.0 12 13 6.3 2.1 0.0 XMMMMF%%.. 4.5 1.3 0.0 13 14 5.8 2.1 0.0 XMMMM%%.. 4.2 1.3 0.0 14 15 5.5 2.1 0.0 XMMMM%%.. 4.1 1.3 0.0 15 16 5.5 2.1 0.0 XMMMM%%.. 4.1 1.3 0.0 16 17 5.5 2.1 0.0 XMMMM%... 4.0 1.3 0.0 17 18 5.3 2.1 0.0 XMMMM%... 3.8 1.3 0.0 18 19 5.1 2.1 0.0 XMMMF%... 3.5 1.3 0.0 19 20 4.9 2.1 0.0 XMMM%%... 3.4 1.3 0.0 20 21 4.8 2.1 0.0 XMMM%%.. 3.3 1.3 0.0 21 22 5.3 2.1 0.0 XMMMF%.. 3.9 1.3 0.0 22 23 9.2 3.6 2.3 MMMMFFF% .. 5.9 0.0 2.2 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) 6-Jul-2025 BoM Space Weather Services, Sydney Australia +61-2-9213-8000