SWS GRAFEX HF FREQUENCY PREDICTIONS ADDRESS NO. 1234 =============================================================================== Circuit: Karratha Perth Date: 5 March, 2026 T-index: 110 Bearings: 184 5 Distance: 1251 km First Mode |--------F r e q u e n c y (MHz)---------| Second Mode 1F 19-26 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 13.1 13.0 7.0 SSXXMM BBB%%... 8.8 8.1 4.2 00 01 14.0 14.5 7.6 ASSXMM MBBP%%%.. 9.5 9.0 4.6 01 02 14.4 15.5 8.1 ASSSXM MBBBP%%... 9.9 9.6 4.9 02 03 14.8 16.1 8.3 ASSSXM MMBBPP%... 10.4 10.0 5.0 03 04 15.0 16.3 8.4 SSSXX MMBBPP%... 10.6 10.1 5.1 04 05 15.2 16.2 8.4 SSSXX MMBBBP%%.. . 10.7 10.1 5.1 05 06 15.3 15.8 8.2 ASSSXM MMBBB%%%.. . 10.7 9.8 5.0 06 07 14.9 15.1 7.9 ASSXXM MMBBP%%%.. . 10.4 9.4 4.8 07 08 14.6 13.8 7.3 SSSXMM MMBF%%%... 10.1 8.6 4.4 08 09 14.3 11.9 6.5 ASSXMMM MMFF%%%... 9.9 7.5 3.9 09 10 13.3 8.4 4.8 ASXMMMMM MFF%%%... 9.3 5.1 2.9 10 11 12.5 2.2 0.0 XMMMMMMMMM FF%%%... 8.7 1.4 0.0 11 12 11.0 2.2 0.0 XMMMMMMMMF %%%... 7.9 1.4 0.0 12 13 10.2 2.2 0.0 XMMMMMMMMF %%... 7.3 1.4 0.0 13 14 9.2 2.2 0.0 XMMMMMMMF% %... 6.7 1.4 0.0 14 15 8.8 2.2 0.0 XMMMMMMM%% %.. 6.4 1.4 0.0 15 16 8.7 2.2 0.0 XMMMMMMF%% ... 6.3 1.4 0.0 16 17 8.6 2.2 0.0 XMMMMMMF%% ... 6.1 1.4 0.0 17 18 7.9 2.2 0.0 XMMMMMM%%% .. 5.8 1.4 0.0 18 19 7.5 2.2 0.0 XMMMMMF%%. . 5.5 1.4 0.0 19 20 6.6 2.2 0.0 XMMMMM%%.. 4.9 1.4 0.0 20 21 6.1 2.2 0.0 XMMMMM%.. 4.7 1.4 0.0 21 22 7.6 2.2 0.0 XMMMMMF%%. . 5.6 1.4 0.0 22 23 11.1 10.6 5.9 ASXMMMB F%%.. 7.4 6.6 3.5 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-Mar-2026 BoM Space Weather Services, Sydney Australia +61-2-9213-8000