SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 9 March, 2026 T-index: 95 Bearings: 184 5 Distance: 1251 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 19-25 1E 5 1 5 10 15 20 25 30 35 40 2F 37-46 2E 14 UT OWF EMUF ALF |...|....| ....|....| ....|....| ....|....| OWF EMUF ALF UT 00 12.8 12.7 6.7 SSXMMM BB%%%... 8.7 7.9 4.1 00 01 13.9 14.2 7.4 ASSXMM MBBP%%... 9.3 8.8 4.5 01 02 14.1 15.2 7.8 ASSXXM MBBBP%%.. 9.6 9.4 4.7 02 03 14.4 15.8 8.1 ASSSXM MMBBP%%... 10.0 9.8 4.9 03 04 14.6 16.0 8.2 ASSSXM MMBBPP%... 10.2 10.0 5.0 04 05 14.7 16.0 8.1 ASSSXM MMBBPP%... 10.3 9.9 4.9 05 06 14.8 15.5 8.0 ASSXXM MMBBP%%%.. 10.3 9.7 4.8 06 07 14.4 14.8 7.6 ASSXXM MMBB%%%... 10.0 9.2 4.6 07 08 14.2 13.6 7.1 SSSXMM MMBF%%%... 9.8 8.4 4.3 08 09 14.0 11.6 6.3 ASSXMMM MFF%%%%... 9.6 7.3 3.8 09 10 12.8 8.0 4.6 ASMMMMMM MF%%%%... 8.8 4.9 2.8 10 11 11.5 2.1 0.0 XMMMMMMMMM F%%%.... 8.1 1.3 0.0 11 12 10.1 2.1 0.0 XMMMMMMMMF %%%.. 7.2 1.3 0.0 12 13 9.2 2.1 0.0 XMMMMMMMF% %%.. 6.6 1.3 0.0 13 14 8.4 2.1 0.0 XMMMMMMF%% ... 6.2 1.3 0.0 14 15 8.2 2.1 0.0 XMMMMMMF%% ... 6.0 1.3 0.0 15 16 8.1 2.1 0.0 XMMMMMMF%% .. 5.9 1.3 0.0 16 17 8.0 2.1 0.0 XMMMMMM%%% .. 5.7 1.3 0.0 17 18 7.6 2.1 0.0 XMMMMMM%%. .. 5.5 1.3 0.0 18 19 7.1 2.1 0.0 XMMMMMF%%. . 5.3 1.3 0.0 19 20 6.3 2.1 0.0 XMMMMM%%.. 4.7 1.3 0.0 20 21 5.8 2.1 0.0 XMMMM%%.. 4.3 1.3 0.0 21 22 7.3 2.1 0.0 XMMMMMF%%. . 5.4 1.3 0.0 22 23 10.9 10.3 5.6 SSXMMBB %%%.. 7.3 6.4 3.4 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) 9-Mar-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000