SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 5 July, 2025 T-index: 70 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 11.9 9.9 5.3 SSMMMMF F%%%.. 7.9 5.9 3.3 00 01 13.7 12.1 6.2 ASSXMMM BBF%%%... 9.1 7.4 3.8 01 02 14.2 13.3 6.8 SSXXMM MBBF%%.... 9.6 8.2 4.1 02 03 14.3 14.0 7.0 SSXXMM MBBB%%.... 9.6 8.6 4.3 03 04 13.8 14.3 7.2 SSSXMM MBBP%%... 9.1 8.8 4.4 04 05 13.6 14.2 7.1 SSSXMM BBBP%%... 8.9 8.8 4.4 05 06 13.4 13.7 6.9 SSXXMM BBB%%.... 8.9 8.5 4.2 06 07 13.4 12.8 6.5 ASSXMMM BBF%%... 8.8 7.9 4.0 07 08 13.3 11.1 5.8 ASXMMMM BFF%%... 8.7 6.8 3.6 08 09 12.7 7.9 4.4 ASMMMMMM FF%%%... 8.4 4.6 2.8 09 10 9.8 2.0 0.0 XMMMMMMMF% %%... 6.7 1.2 0.0 10 11 7.3 2.0 0.0 XMMMMMF%%. ... 5.2 1.2 0.0 11 12 6.1 2.0 0.0 XMMMMF%%.. 4.4 1.2 0.0 12 13 5.6 2.0 0.0 XMMMM%%... 4.2 1.2 0.0 13 14 5.3 2.0 0.0 XMMMM%... 4.0 1.2 0.0 14 15 5.1 2.0 0.0 XMMMM%... 3.9 1.2 0.0 15 16 5.1 2.0 0.0 XMMMM%... 3.9 1.2 0.0 16 17 5.1 2.0 0.0 XMMMM%... 3.8 1.2 0.0 17 18 5.0 2.0 0.0 XMMMM%... 3.6 1.2 0.0 18 19 4.9 2.0 0.0 XMMM%%... 3.5 1.2 0.0 19 20 4.8 2.0 0.0 XMMM%%.. 3.3 1.2 0.0 20 21 4.6 2.0 0.0 XMMM%%.. 3.2 1.2 0.0 21 22 4.9 2.0 0.0 XMMM%%.. 3.7 1.2 0.0 22 23 8.1 2.0 0.0 MMMMMMFF%. . 5.5 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) 5-Jul-2025 BoM Space Weather Services, Sydney Australia +61-2-9213-8000